“I can’t breathe… I have to stop.”

I still remember that humid Bali morning. I was hunched over, gasping for air, while the rest of my running group pulled ahead like it was no big deal. I honestly thought being out of breath was just part of the deal — something I’d always have to live with.

Fast forward a few years, and now I’m that guy cruising up steep jungle trails, barely winded. What changed? I started training my breath — specifically, my carbon dioxide (CO₂) tolerance. Fancy name, but trust me, the idea is simple. And powerful.

This isn’t hype. This is real science mixed with experience — both mine and the runners I coach. We’ll get into what CO₂ tolerance really means, why it matters more than you think, and how it can change your running for good. Plus, I’ll walk you through how to start training your breath today with some simple, real-life tips.

So take a deep breath (through your nose if you can!), and let’s get into it.

I Couldn’t Breathe… Until I Learned to Breathe Right

Back when I started running, I couldn’t make it one block without wheezing. Picture this: a sweaty twenty-something guy in Denpasar, Bali, trying to jog in the morning heat, heart pounding like a drum solo, and lungs screaming for air.

One memory stands out — I was running up Campuhan Ridge, one of the prettiest routes in Ubud. But I was too busy sucking wind to enjoy any of it. I remember thinking, “Maybe I’m just not built for this.”

Turns out, I wasn’t short on oxygen — I just didn’t know how to use it properly. I was mouth-breathing like crazy, flushing out CO₂ too fast, which left me more breathless. It was a frustrating loop: the more I gasped, the worse it got.

My wake-up moment? An ultra runner from our group passed me with his mouth shut, breathing calmly through his nose. Afterward, over post-run coconuts (yes, very Bali), he explained something that floored me:

“You’re not running out of oxygen — you’re just not handling carbon dioxide well.”

Wait, what?

Apparently, it’s not low oxygen that makes you feel breathless. It’s the rise in CO₂. And the crazy part? You actually need a bit of that CO₂ to get oxygen where it needs to go. That lit a fire in me. I started researching, experimenting, and slowly learning to breathe better. It completely changed the way I run.

What is Carbon Dioxide Tolerance (and Why Should You Care)?

CO₂ tolerance is your body’s ability to stay cool when carbon dioxide builds up — especially during hard efforts.

Here’s how it works:

When you move, your muscles create CO₂ as they burn fuel. This gas builds up in the blood. Your brain doesn’t panic because oxygen is low — it panics when CO₂ gets too high.

Most people freak out when that happens. They breathe faster to get rid of it. But here’s the catch:

CO₂ is actually what helps oxygen get delivered to your muscles.

Thanks to something called the Bohr effect, higher CO₂ levels make hemoglobin release oxygen more easily. So if you hyperventilate and blow off all your CO₂, your body holds onto oxygen — and your muscles get less of it.

Let that sink in…

The very thing that feels like the right move — breathing faster — can backfire and leave your muscles starved for oxygen.

That explained a lot about my old struggles.

The Real Benefits of Training Your CO₂ Tolerance

Building CO₂ tolerance isn’t about being a breath-holding wizard. It’s about improving how your body handles stress, effort, and fatigue.

Here’s what happens when your body learns to tolerate more CO₂:

🫁 More Oxygen Where You Need It

Higher CO₂ = better oxygen delivery (Bohr effect again). That means your legs get what they need during those tough miles — especially on hills or long runs.

❤️ Better Blood Flow

CO₂ helps your blood vessels relax and open up. That means more blood to your muscles, more nutrients delivered, and more waste carried away.

🧘 Lower Heart Rate, Slower Breathing

Once you stop panicking about the breath, you naturally breathe slower and deeper. That leads to a lower heart rate at the same pace. I now talk through runs that used to leave me gasping.

💪 More Endurance, Faster Recovery

When you use less energy on every breath, you’ve got more gas in the tank for your legs. Plus, your body bounces back faster post-run — breathing calms down, heart rate drops, and you’re ready for round two sooner.

🧠 Mental Toughness

Breath training teaches you to stay calm when your body says, “Panic!” That skill? It’s gold during mile 20 of a marathon or the final rep of a brutal workout. It also spills over into life — a lot of runners report feeling less anxious day-to-day.

Reality Check: It’s Not Magic, But It’s a Game-Changer

Let’s be real: training your CO₂ tolerance won’t turn you into Kipchoge overnight. It’s one piece of the puzzle. But it’s a powerful one most runners ignore.

We obsess over VO₂ max and oxygen intake — but forget the oxygen has to be delivered to matter. CO₂ is the delivery key.

By learning to sit with that breathless feeling — not panic, not over-breathe — you teach your body to run smarter, not just harder.

For me, it was like upgrading my engine’s software. Same legs. Same lungs. But a totally different level of control and calm under pressure.

How CO2 Tolerance Training Can Boost Your Running Without Fancy Gear

So, how does all this breath-holding stuff actually help when you’re out grinding miles? Let’s break it down runner-to-runner:

1. You’ll Breathe Easier at the Same Pace

After just a few weeks of CO2 tolerance drills, I noticed something weird (in a good way): I wasn’t gasping for air as much. Those routes that used to leave me huffing? Suddenly manageable. Not because my legs magically got stronger—but because my breathing got more efficient.

That’s the point. Better CO2 tolerance = more oxygen delivered to your muscles without hitting the panic button too soon. It’s like lifting the roof off your endurance—you’ve got more airspace to work with.

📚 According to one study, CO2 training boosts oxygen availability by improving your body’s ability to use what’s already there.

Try this: Next time you’re on an easy run, pay attention. Are you gasping at mile two, or staying steady? That change says more than your watch ever could.

2. Lower Heart Rate, Better Endurance

You know that panicky, “oh crap I’m dying” feeling when your breathing spikes and heart rate jumps through the roof? Been there.

Once I started slowing down my breathing and focusing on nasal inhales, my heart rate dropped—same pace, less effort. It made long runs feel smoother, even during marathon prep. I wasn’t burning out early because my body wasn’t yelling at me to breathe.

📚 Again, study backs this: Training yourself to tolerate CO2 shifts your ventilatory threshold—you can run faster or longer before that heavy breathing kicks in.

Coach’s Note: This is clutch in longer races. The calmer your breathing, the longer you can stay in the zone.

3. You’ll Recover Faster Between Reps or Hills

We’ve all topped a steep hill or hammered through a rep feeling like we just swallowed fire. But here’s the thing—after working on CO2 tolerance, I could actually catch my breath faster. No more gasping like a fish.

This happens because your chemoreceptors (the little sensors in your brain that scream when CO2 builds up) stop overreacting. You train your body to chill—even when things get spicy.

📚 Cyclists talk about this a lot too—more CO2 tolerance = slower, deeper breathing = faster bounce-back.

Runner Reality: When you crest that climb, you’re back in the game quicker. That’s a real edge on race day.

4. More Efficient Oxygen Use = Better Running Economy

Running economy isn’t just strong legs—it’s how little oxygen you burn for the same pace. I switched to mostly nasal breathing on my easy runs and felt like I traded in my old clunker for a hybrid.

📚 Some studies even suggest nasal breathing can help runners maintain VO₂ max while reducing how much air they need.

The crazy part? I could breathe through my nose at tempo pace. That used to sound impossible. Now it’s just training.

5. Stronger Mind, Sharper Focus

This might be my favorite part: mental toughness.

Those breath-hold drills where your brain is screaming “BREATHE NOW”—yeah, they’re uncomfortable. But that’s the whole point. You learn to stay calm when everything says “panic.”

In races, when your body’s freaking out, you fall back on that breath control. I’ve seen runners shave minutes off their times just by not panicking mid-race.

I tell my crew all the time: “When it gets hard, lock in on your breathing. Anchor yourself.”

📚 Breath control has legit mental benefits too. It trains your nervous system to stay in control under pressure.

⚠️ But Don’t Throw Out Your Mileage Just Yet…

Let’s not get carried away. Some scientists are skeptical. If you’re already in great shape, your oxygen saturation during workouts is likely around 98–100%—so boosting CO2 might not drastically change that.

📚 One study showed nasal breathing didn’t improve VO₂ max in trained runners. Another found that better BOLT scores didn’t always lead to faster race times over a few weeks.

That said, don’t ditch your long runs or intervals. Breath training isn’t a magic bullet—it’s more like adding polish to the engine. It’s about feeling smoother, not suddenly gaining superpowers.

In My Experience: What changes most is comfort, control, and your ability to stay composed. And that often does lead to faster times because you’re not tapping out early.

🧪 Testing Your CO2 Baseline: The BOLT Score

Want to know where your breathing stands? Try the BOLT test. It’s super simple and surprisingly telling.

I call it the “control pause.” It’s basically a snapshot of how chill your breathing system is.

Here’s how to test it:

1. Sit and relax. Ideally first thing in the morning or after 10 minutes of rest.
2. Take a normal inhale, then exhale normally through your nose.
3. Pinch your nose and hold. Start timing.
4. Stop when you feel the first strong urge to breathe. Don’t go full hero mode—no gasping allowed.
5. Check your time. That’s your BOLT score. Resume nasal breathing calmly.

📚 Most folks score around 20 seconds.

If you’re under 10 seconds, your system’s stressed—maybe poor sleep, fatigue, or just shallow breathing. Around 20? Not bad, but room to grow. Hit 30+ and you’re breathing like a pro. Over 40? That’s elite territory.

Patrick McKeown—the guy behind The Oxygen Advantage—says 40 seconds is the gold standard.

Final Thoughts: Is It Worth It?

If you’re serious about running—not just surviving runs but feeling good out there—CO2 training is worth a shot. No gear. No subscriptions. Just your breath, your body, and a bit of discomfort.

I’ve used it. I coach it. And it works—not in flashy PRs out of nowhere, but in the quiet moments where you realize, “Hey, I’m not dying at mile five anymore.”

👟 Your Turn:

What’s your BOLT score?

Have you tried nasal breathing or breath-hold drills?

Drop a comment and let’s talk about how it’s helped—or frustrated—you. This stuff is simple, free, and can make a difference.

Let’s breathe smarter, not just harder.

CO2 Tolerance Training for Runners: A Real-World Breathing Upgrade

Let me be honest with you—my first BOLT score was 16 seconds, and I felt like I was suffocating.

That tight, panicky feeling? It was my body freaking out over CO2. But like any muscle, your tolerance can be trained. These days, I hover around 40 seconds, and I swear—my running feels like I unlocked a secret level. Easier breathing, smoother pace, and way less gasping. Keep your BOLT score handy—we’ll check in again after some training and you’ll see the change for yourself.

Coach tip: Treat the BOLT test like checking your battery. A big drop one morning? That could be your body telling you it’s stressed out, under-recovered, or riding the edge of burnout. CO2 tolerance tends to dip when you’re anxious or fatigued. On those days, back off a bit or focus on recovery instead.

Call to Action: Try This Mini Experiment

Tomorrow morning, measure your BOLT score. Write it down. Then commit to two weeks of simple breath work:

• Nasal breathing during runs
• Breath holds or box breathing before bed

After 14 days, test your BOLT again. Even a few seconds of improvement is proof that something’s shifting. But more importantly—check in with how your runs feel. Are you less winded on those easy miles? Recovering faster after speed work? That’s the real win.

Embrace the Discomfort: Turning Breath Training into Running Gains

Ultimately, improving your breathing is about improving your running experience. Running will feel less like a fight for air and more like a flow. You’ll likely run faster or farther before fatigue sets in, and even if you don’t become Mo Farah overnight, you’ll enjoy running a heck of a lot more when you’re not constantly gasping.

For me, that meant the difference between quitting running out of frustration and becoming a lifelong runner and coach. That’s the power of learning to breathe better.

So, take a deep (nasal) breath, and take the plunge into CO2 tolerance training. Your lungs, legs, and even mind will thank you. The next time you find yourself in that tough part of a run where your chest is burning, you’ll smile knowing you’ve trained for this very moment. And as you exhale, you’ll push onward, stronger and calmer than before.

Happy breathing and happy running!

Ever wonder if someone like you—maybe a brand-new runner—can actually go from zero to marathon-ready?

I’ve been there. I’m David Dack, a running coach living in the sweaty chaos of Bali, and I used to ask myself that same question. My marathon journey didn’t start with talent or some perfect training plan. It started with struggle—real struggle.

I remember dragging myself through humid 5 a.m. runs, feeling like every step was a mistake. My lungs burned after 15 minutes. I’d hear that nagging voice in my head whisper, “You’re not built for this.” But I kept coming back. I’d tell myself, “Just one more lap. Just five more minutes.” That mindset—matched with smart, slow mileage building—is how I made it from gasping beginner to running over 70 km a week. Injury-free.

This guide is my blueprint. It’s what helped me finish marathons without burning out or ending up sidelined. And if I can pull it off in Bali’s brutal heat, dodging motorbikes and potholes, trust me—you can too.

Why Mileage Matters in Marathon Training

Before you think about pace, tempo runs, or hill repeats, you’ve got to stack your miles. Easy miles. These quiet, steady efforts are what build your foundation.

Here’s what’s really going on under the hood when you pile on smart mileage:

You build an aerobic engine

That’s your long-haul system. Each easy run helps your body adapt—more mitochondria, more capillaries feeding your muscles. You burn fat better and stay strong longer.

Your heart levels up

Literally. It gets stronger and pumps more blood per beat, which means more oxygen goes to your muscles with less effort. That’s why your resting heart rate drops the more consistent you get.

You move better and waste less energy

Mileage helps stiffen your tendons and shift your muscles to more efficient slow-twitch fibers. The result? You start gliding more, struggling less.

Even running just 20–30 km a week has been shown to seriously boost cardiovascular health and endurance, according to research on recreational runners.

Sure, elite marathoners can hit 160 km weekly, but that’s after years of layering smart volume. You don’t need that to start—you just need to build. Gradually.

Mental Toughness: The Real Key to Upping Your Mileage

Let’s be honest—building mileage isn’t just about legs or lungs. It’s a mental fight too. Some days you’ll love the grind. Other days, even lacing up feels like a chore. I’ve been there.

I still remember dragging myself through a 25K run in Bali, the sun melting me, while my brain screamed, “What the hell are you doing this for?” But over time, I picked up a few tricks to stay in the game.

Break it Down

Thinking “25 km left” is a surefire way to freak yourself out. Instead, I tell myself, “Just make it to that warung” or “One more song.” That’s called chunking.

According to research on noneotorun.com, breaking down long distances makes the whole thing feel easier—and we naturally move quicker. When I’m out there, I treat the run like checkpoints: 5K here, another 3K there. Suddenly, I’m not overwhelmed by the whole mountain—I’m just climbing one step at a time.

Talk to Yourself (Nicely)

Don’t wait for a pep talk. Give it to yourself.

Studies have shown that runners who repeat mantras like “Stay on” or “You’re doing great” actually perform better than those who don’t practice any self-talk. For me? I use, “I am strong” or “One more push.”

And on the worst days? I speak in third person—“You got this, David.” It sounds ridiculous, but it works. It shifts your mindset when the pain creeps in.

Distract the Mind

Music, podcasts, or a chatty running buddy can be game changers. Research backs it—pleasant distractions help reduce the feeling of effort during long runs.

Personally, there’s nothing like watching the sunrise peek over Bali’s volcanoes while my feet are pounding the pavement. It keeps my brain engaged and far from complaining.

Make Friends with Discomfort

I used to hate the pain. Now, I see it as growth. Every run that sucks is building something.

When I grind through a hill repeat or a sweaty long run, I remind myself: “That hurt, and I didn’t quit. That means I’m getting tougher.” You’re not just training your body—you’re training your grit.

And let’s get this straight—you’re going to have garbage runs. Days where your legs feel like bricks, or your stomach rebels. Instead of sulking, ask: “What did this teach me?”

Bad fueling? Too little sleep? Learn and move on.

And when things click? Celebrate it. I still remember my first 20K run like it was a festival. Sat down, smashed three plates of nasi campur, and thought, “Holy crap, I might actually be a runner.”

Mileage Progressions That Actually Work

Here’s a simple 12-week blueprint—nothing fancy, just numbers that work. Adjust based on your fitness and life.

Beginner: Build from 40K to 60K Per Week

Advanced: Build from 60K to 80K+

Every 4th week, ease up to let your body recover. And don’t just stack long runs—mix in easy days, tempo work, and some cross-training.

Nothing here is written in stone. If your legs are fried, back off. If you’re cruising, hold that peak a little longer. Just don’t let your ego push you into the injury zone.

👉 Want to plan it all out? Grab my 12-Week Marathon Mileage Planner to build your own schedule that fits your life.

My Real Story: From 10-Minute Gasps to Marathon Legs

When I started, I could barely run for 10 minutes without gasping like a fish on land. A 10K felt like Mount Everest. The marathon? That was laughable. But I had this stubborn voice that whispered: “What if you just try?”

So I did.

My early runs were short and brutal. I broke them into chunks. 2K, then 3K, then maybe 5. Some days I ran through scooter traffic and mosquito clouds. Other days the Bali heat made 5K feel like survival training.

I learned to adapt: early morning runs, shady routes, treadmill during monsoons—whatever it took to stay moving.

I didn’t follow some flashy plan. I just increased mileage slowly—around 10–15% a week. Some days I felt great and ran a little more. Other times, my legs begged for mercy.

I ignored early shin splints and paid for it—two weeks off and a hard lesson in respecting recovery.

Walk breaks? Hell yes. Especially in the heat. I’d go 5 min run, 1 min walk, and finish strong instead of crawling. That’s not weakness—that’s smart.

Nutrition? Learned the hard way. Dizzy, bonking, sitting on a curb thinking, “Maybe I should’ve eaten something.” Now I fuel up before, during, and after. Banana. Coffee. Gels. I know my window and how to dodge “the wall.”

Strength training was the game-changer. I used to think more miles = better. Wrong. At 40K a week, my body was yelling. I added squats, lunges, deadbugs—and like magic, my knees stopped barking.

No coach. Just online buddies, my runner girlfriend, and the odd Reddit thread. That accountability kept me honest.

My biggest fear? “What if I train for months and still crash on race day?” But I flipped it—if training sucks now, good. I’m learning to fight.

The week I hit 70K was surreal. My body ached, but my heart rate dropped. I was stronger than I thought.

If I could talk to my old self? I’d say: “Forget the finish line. Just show up tomorrow. Run. Rest. Repeat. You’re not chasing 42K—you’re building the kind of person who can handle it.”

And if you’re reading this, you’re already on that path.

Common Questions Runners Ask Me About Mileage

🏃 Is running every day safe when you’re training for a marathon?

For most people—especially beginners—the answer is no. Running 7 days a week without rest is asking for trouble.

Your muscles need time to bounce back, and those rest days are where the real growth happens.

I always recommend 1–2 rest days or low-impact days (like yoga, cycling, or swimming). You’re still moving, but you’re giving your legs a break from the pounding.

Think of recovery as part of the training cycle, not something you earn after a race. Research backs this too—proper rest can actually improve performance and cut down injury risk.

🧠 My rule: If your legs feel trashed when you wake up, you probably needed that rest day yesterday.

⚖️ Should I build more mileage or add speed first?

Mileage. Always mileage.

Here’s why: speed work breaks you down. Mileage builds you up.

If your aerobic base isn’t ready, piling on intervals is like adding nitro to a weak engine—it might feel fast for a while, but eventually, something blows.

So before you throw in hill repeats or tempo runs, lock in your base. Get consistent at your weekly distance. Only after you’re running steady for a few weeks should you test the gas pedal.

Build the engine first. Then you can start tuning it.

🔁 I took a break—how fast can I bounce back?

That depends on your base.

If you’ve run 60K weeks before, you’ll likely bounce back fast—maybe in three weeks (like 30 → 45 → 60K). Muscle memory is a gift like that.

But if you’re starting from scratch or returning from injury, don’t rush it. You’re not behind—you’re just rebuilding.

Listen to your body more than your ego.

I’ve come back from breaks thinking I was still in shape… and paid the price. Respect the process.

💪 How do I add strength and cross-training without overdoing it?

Easy—just be smart about placement.

I like to lift twice a week (20–30 min max), usually on easy run days or right after an easy jog. That way I’m not piling stress on speed days.

You can also swap a short run for an easy swim or spin on the bike. Ten minutes of something light still counts.

The key? Keep it consistent and short.

I learned the hard way that strength work actually makes running feel easier—not harder. Two sessions a week? Total game changer.

Final Mileage Advice from the Trenches

📈 Progress is about consistency—not crushing big numbers.

One more run each week. One more easy kilometer. That’s the real win.

Not every week will be record-breaking, and that’s okay. The grind builds grit. The people who get faster are the ones who show up when it’s boring, not just when it’s fun.

🛌 Rest isn’t weakness. It’s strategy.

You don’t start losing fitness until you’ve skipped training for two full weeks. So stop panicking over a missed run. One good rest day can make the next five days better.

Some of my best training weeks happened right after a guilt-free day off.

⏳ Be patient—real fitness takes time.

Running a marathon isn’t something you cram for. It’s months of buildup, setbacks, and steady growth. Don’t judge progress by one week’s numbers.

Look at the bigger picture. Trust your blocks. Your body will catch up if you give it time.

It took me months to break 50K per week without breaking myself. But when it clicked, I felt like I’d leveled up as a runner.

🏅 The race is just one day. The real win is the lifestyle.

Marathon day is awesome, sure. But the real joy? It’s in the habits—the daily grind, the solo runs, the small PRs, the post-run nasi goreng.

If you fall in love with the process, race day becomes a celebration, not a test.

What flipped the switch for me?

One mindset: “Slow progress is still progress.”

I stopped chasing big leaps. I learned to trust the boring days. And I started sharing my story—every struggle, every tiny win. That kept me honest and gave others the courage to keep going too.

You don’t need to be elite. You just need to keep moving forward.

If you’ve read this far, you’re serious. You’re learning. You’re probably hungry to do this right.

And that’s exactly what it takes to become a marathoner—curiosity, patience, and grit.

👣 Every single marathoner started with a first run. You’re already on your way.

I’ll never forget the Bromo Half Marathon in East Java.

As a Bali-based running coach, I was used to flat coastal routes, so I thought 13.1 miles was just 13.1 miles—how tough could a few hills be?

Turns out, a whole lot tougher than I expected. By mile 9 of that race, staring up at yet another volcanic incline, I was wiped out and mentally questioning if I’d even finish.

At that point, the half marathon felt less like 21 kilometers and more like 25 or 30.

It wasn’t all in my head—course elevation really does make a race feel longer.

Let’s dig into why hills mess with your pace and how they mess with your mind. I’ll also share a few hard lessons from Bromo and give you some tips to help you power through hilly half marathons.

Half Marathon Elevation Gain vs. Flat Courses 

Running a half marathon on a flat course is already a tough challenge, but add some significant elevation gain and you’ve got yourself a whole new beast.

Elevation gain is how much you climb during a race. Even if the course is still 13.1 miles long, those uphill stretches will feel “longer” because you’re using up more energy and taking more time to get over them.

Some trail running advice I’ve heard says that for every 100 meters of elevation gain, you should mentally add about 1 kilometer to your race in terms of effort.

It’s not perfect math, but it’s a good rule of thumb. A half marathon with, say, 300 meters of climbing might feel like running a 16K on flat ground.

Let me put it this way: during my Bromo race, where the first 21K was essentially a half marathon, I climbed around 900 meters in that first half. By the time I reached the actual 21.1K mark, I was as spent as I’ve ever been at the end of some flat full marathons.

That day, I learned that miles with elevation feel twice as hard. I later found out this isn’t just my personal feeling. Coaches and mountain runners refer to Naismith’s Rule, which suggests that for every 100 meters of ascent, you should add about 800–1000 meters of “equivalent” flat distance.

Hills literally add distance to how your body experiences the effort. No wonder that Bromo Half felt endless!

Does Elevation Make a Race Feel Longer? 

100% yes. A hilly half marathon will feel harder and longer than a flat one, even though the official distance stays the same.

That’s because the extra time spent huffing it uphill means you’re on your feet longer and racking up fatigue. I remember during Bromo, every uphill segment made the race feel like it was stretching on forever.

It’s not just in your head—scientific studies back this up. One study found that, even when a race course has equal ups and downs, runners’ times were about 2.5–2.8% slower on hilly courses compared to flat ones.

In a half marathon, a 2.5% slower time could add several extra minutes, and that’s definitely noticeable when you’re running.

Physiologically, running uphill ramps up your heart rate and your breathing. Your legs burn because they’re working harder to fight gravity.

I can still remember gasping for breath on a steep incline around mile 5 of the Bromo Half, my pulse racing even though I was barely moving. Every switchback felt like it was pulling me further from that 13.1-mile goal.

So yeah, elevation makes the race longer—not just in terms of time but also in how your brain perceives the challenge.

And don’t be fooled into thinking downhill stretches will fully make up for the uphill grind. You never really “earn back” all the time lost during climbs.

Experts say that for every 100 feet of uphill, the average runner only gains about 15–20 seconds on the downhill. Gravity helps you on the way down, but it doesn’t fully offset the energy spent climbing.

I saw this firsthand in Bromo: I’d tear down a hill at what felt like lightning speed, but my split times were still slower than what I’d see on a flat course. The uphill battles just take way more out of you than the downhills can repay.

The Mental Game of Hilly Races

Let’s be real—hilly courses are also a mental battle. When you know there’s a climb ahead, every hill becomes a challenge for your brain.

It messes with your perception of distance. You look at the miles ticking by and think, “How the heck am I only at mile 8?” because the effort distorts your sense of time.

On flat courses, you can zone out and find a rhythm, but on hills, you’re constantly engaged—usually in discomfort—and it feels like you’re working double-time. Each mile on a hilly course feels like a hard-earned victory.

As a coach, I tell my runners that a hilly race requires not just physical training but mental toughness. You’ve got to be prepared to push through the fatigue and not let the mental struggle break you down.

It’s all about setting realistic expectations: you’ve got to understand that a hilly race is going to be harder and take longer.

So when you cross that finish line, don’t think of it as a failure because it took longer than you planned. Think of it as a stronger performance than running the same distance on an easier course.

Running Uphill vs. Flat 

Let’s get one thing straight—running hills isn’t just harder. It’s a totally different beast.

You feel it the second you hit an incline. Your pace drops like a rock—and it should. Because trying to force your usual speed on a hill is the fastest way to blow up your race (or your lungs).

You’re suddenly fighting gravity, lifting your body weight step after step. It’s like someone flipped the difficulty switch to “extra hard” without warning.

And the data backs this up. According to a classic study, even a small 1% incline can slow your pace by 12 to 15 seconds per mile if you’re running between 7:30 to 10:00 per mile.

Hit a 2% grade? Expect double that.

“But I’m Slower on Hills!”  

This is something I drill into my runners (and honestly, myself too). Pace on hills is all relative. A 9:00 mile on the flats might take 10:00+ going uphill—and that’s perfectly normal.

I always urge my runners to run by effort, not pace on hills. You don’t need a fancy study to prove it—just try breathing through your nose at the same pace uphill and watch your heart rate skyrocket.

During the Bromo Half, I ditched my time goal as soon as the first real climb started. I wasn’t chasing splits anymore—I was just trying to survive.

I shortened my stride, focused on breathing, and even hiked a few stretches. And you know what? That saved my legs later.

The Muscle Shift: Hills Work You Differently

Hills don’t just mess with your pace—they work your glutes, quads, and calves in a way that flat running never will.

Your stride shortens. Your steps get quicker. Your body shifts into climbing mode.

Even if you’re moving slower, your effort level jumps. One study showed that runners had higher blood lactate levels on hill courses, despite running slower.

Translation? You’re working harder uphill whether your watch says it or not.

I felt this in Bromo—halfway up a steep section, my legs were screaming and I was barely jogging. That burn? That’s lactic acid saying hello. And that’s when you know the climb is real.

Downhill Running 

Once you crest the top of a hill, you finally get that glorious downhill. Gravity gives you a hand. You can catch your breath.

Your pace might even drop a full minute or two compared to the uphill before it.

I remember flying down a sandy downhill at Bromo, laughing like a maniac as I let my legs go. It felt like a free ride… for a while.

But there’s a price.

Downhill running can pound your legs with 50–75% more impact force than flat ground. That force hits your quads the hardest.

They’re doing the braking while you’re flying downhill. If you’re not ready for it, a long descent can turn your legs to jelly.

And trust me—I’ve been there. After a 3K downhill at Bromo, my quads were already trembling, and I still had more climbs ahead.

It’s like borrowing speed and paying for it later—plus interest.

What About Downhills?

Sure, you’ll gain a little time.

I’d suggests around 8 seconds faster per mile for every 1% downhill.

But notice that’s only about half of what you lost going uphill. So don’t count on downhills saving the day entirely—especially if they’re too steep to safely bomb down.

Unless you’re on a net downhill course (and even then, there’s a limit), hilly runs will slow your average pace. That’s just how it goes.

Use GAP to Keep Perspective

If you’re using Strava, check out GAP (Grade Adjusted Pace). It’ll show you what your hilly run felt like effort-wise if it were flat.

I’ve had runs where I slogged up 11-minute miles, only to see that my GAP was equivalent to 9:30s. That’s the kind of validation you sometimes need.

How Elevation Gain Affects Your Half Marathon Time

Alright, let’s get real—hills change the game. If you’re gearing up for a hilly half marathon, you’re probably asking:

“How much slower will I be?”

Short answer: you will be slower.

How much? That depends on a few key things—how much elevation there is, how the climbs are spread out, and whether you’ve trained for them.

So… how much does 500 feet of climbing slow you down?

Here’s the ballpark: most coaches agree that for every 100 feet (about 30 meters) of elevation gain, you might add 1 to 2 minutes to your half marathon time.

That’s not gospel, but it’s a good starting point.

Let’s say you’re a 2-hour half marathoner on a flat course. If your race has 500 feet of climbing, expect to be 5–10 minutes slower.

And yeah, that checks out with what we see in real-world races and physics-based models.

According to Runner’s World, even elite runners lose about 20 seconds per 100 feet climbed. For us mere mortals? Closer to 30–40 seconds.

And going downhill doesn’t give you all that time back—maybe 10–20 seconds per 100 feet if you’re lucky. That’s assuming you don’t shred your quads or wipe out.

Translation: a course with a ton of up-and-down will likely leave you with a slower overall time than a pancake-flat route.

Flat vs. Hilly

I learned this the hard way. In 2022, I ran two half marathons just months apart.

One was a flat road race in Jakarta—hot and humid, sure, but no hills. I ran one of my best times that year.

The other? Another bromo Half. Beautiful course, meaningful cause, but ~1300 feet of climbing. Same fitness level, same prep—and I finished 15 minutes slower.

I hadn’t gotten slower. The hills just crushed me.

At around kilometer 18, I hit the top of a brutal hill with my legs wobbling and my heart pounding. I remember thinking: “If this were flat, I’d be DONE by now… but nope, now I have to run down this beast.”

That day taught me that finish time doesn’t always show your fitness. Course profile matters. Sometimes, finishing strong on a hard course is more of a win than a shiny new PR on an easy one.

How to Adjust Your Game Plan for a Hilly Race

Let’s break this down. If you’ve got elevation on race day, your approach needs to shift.

Here’s what I tell my runners:

1. Start Smart (Not Heroic)

On a flat course, you might get away with a hot start. On a hilly course? That’s a rookie mistake.

Be conservative early on—especially if there’s a climb in the first few miles. Some runners even plan walk breaks on steep sections.

I’ve done it. I power-hiked the caldera climbs during the Bromo Half. No shame in that—it saved my legs.

2. Run by Effort, Not Pace

Forget the watch on the hills. Use your effort meter, or a heart rate monitor if you like gadgets.

Going all-out on the first climb is a recipe for regret.

I’d recommend to shorten your stride, keep your cadence steady, and don’t hunch forward. Stand tall. Stay smooth.

That rhythm—even if it’s slower—is what gets you to the top without frying your legs.

3. Respect the Downhills

Downhills can be your friend—or your destroyer. If your legs aren’t used to them, you’ll get wrecked.

I once bombed a training downhill like a maniac. Felt amazing—until I couldn’t walk right the next day. Quads were toast.

During training, work in some downhill repeats. Get those muscles used to the pounding.

Then on race day, lean in, take light, quick steps, and flow with the terrain. It’s free speed if you’ve earned it.

4. Fuel Early and Often

Hilly races take longer. That means you’ll be out there burning more energy.

Here’s my mistake: during the Bromo race, I skipped an energy gel early because I was out of breath on a steep climb.

Dumb move.

By the next aid station, I was running on fumes.

Fuel before you think you need it—especially if the course profile delays aid stations. Hills suppress appetite, so practice eating when breathing hard during training.

5. Train for the Terrain

If your local runs are all flat, and your race isn’t, you’re in for a shock.

I’ve had beginner clients training in Bali for the Yogja Half. Flat routes all week—then race day comes and they get chewed up by the hills.

That’s why I tell them: once a week, go find a hill and do repeats. If you don’t have hills, incline treadmill, stadium stairs, parking ramps—whatever it takes.

Race day isn’t the time to meet hills. It’s where you show you’ve already made friends with them in training.

6. Mentally Chunk the Course

Hilly races are mentally exhausting. Instead of thinking “13.1 miles,” I tell myself,

“Get up this hill. Then recover. Then get to the next one.”

Break it down. Stack wins. Each hill becomes a checkpoint, not a wall.

Conclusion 

Now it’s your turn. You’ve got the knowledge, the strategies, and hopefully a fired-up attitude.

Take these insights to heart and to your training. The next time you line up at a hilly half marathon start line, you’ll do so with confidence and a game plan.

When the gun goes off, you won’t fear the course – you’ll embrace it, every uphill grind and downhill fly.

And when you hit that finish, you’ll know that no matter the number on the clock, you achieved something special.

Lace up, get out there, and get ready for the hills – they’re ready for you, and they will make you a stronger runner than you ever thought possible.

See you at the top!

A few years ago, I found myself sitting on my porch, heart racing, thoughts spiraling, trapped in the kind of anxiety that tightens your chest and makes it hard to breathe.

It was one of those nights where my mind wouldn’t shut off – just running in circles, feeding into the worry.

In a moment of desperation, I threw on my running shoes and decided to head out into the warm tropical night.

I wasn’t looking to break any records; I just needed an escape.

As my feet hit the pavement and the humid air filled my lungs, something unexpected happened: my mind started to slow down. By the time I got home, tired but at peace, my anxiety had loosened its grip.

For the first time that day, I felt like myself again. It got me wondering: does running really help with anxiety?

In my experience, the answer is a big yes – but it’s not a quick fix, and it’s definitely not a replacement for professional help.

In this article, I’ll take you through my personal experience with running and anxiety, break down why running is such a powerful tool for anxiety relief, and offer practical tips to get started.

Let’s get to it.

My Anxiety and How Running Became My Release

I haven’t always been the running coach living in Bali. In my early 20s, I was just a guy struggling with anxiety.

Back then, it felt like I had a heavy cloud following me everywhere.

I’d wake up with a knot in my stomach, already thinking of a dozen “what-ifs” before my feet even hit the floor. Whether it was work stress, personal problems, or sometimes nothing at all, anxiety would hit me out of nowhere.

I tried the usual distractions – binge-watching TV, browsing the internet – but those were just temporary band-aids. The anxiety always crept back.

Then running entered my life almost by accident. One particularly tough day, after hours of feeling on edge, I decided I needed to do something, anything, to break the cycle.

I remembered an old pair of running shoes collecting dust in my closet.

With nothing to lose, I put them on and jogged around my neighborhood for about 15 minutes.

It wasn’t pretty – I was gasping for air, out of shape – but when I stopped, I realized something surprising: my hands weren’t shaking anymore.

My thoughts weren’t racing.

I felt a noticeable shift, like I had just flipped a switch on my stress. That short run didn’t fix everything, but it made me feel lighter.

From that day, running evolved from just a workout into my therapy in motion. Whenever anxiety started bubbling up – that tight chest, that racing heart – I learned to lace up and run through it.

I’ll never forget one night when panic hit me out of nowhere (you know how it is, anxiety doesn’t give you a warning). It was around 9 PM, and I could feel the familiar wave of dread taking over.

Instead of sitting around, feeling trapped, I threw on my running shoes and ran under the moonlight along a quiet beach road. The rhythm of my footsteps in the sand, the sound of the waves crashing in the distance, my deep breaths – all of it brought me back to the moment.

By the end of that run, the panic had melted into a calm exhaustion.

I leaned against a palm tree, sweat pouring down my face, but I was smiling. I felt okay.

Little by little, run by run, I realized that running gave me a sense of control over my anxiety that I’d never had before.

But let’s be real: Running didn’t cure my anxiety overnight. It didn’t fix everything, and it’s not a miracle solution. But it became one of the most reliable tools in my toolbox.

I still had anxious days (and I still do), but I knew that even a short jog could ease the worry, or sometimes even chase it away entirely. Soon, I started calling my morning runs my “moving meditation” or my “cheap therapy.”

Over time, I also realized I wasn’t alone in this. So many people face anxiety – in fact, about 40 million adults in the U.S. alone suffer from diagnosed anxiety disorders.

It’s a huge issue, and many of us are looking for ways to feel better that don’t just rely on medication or sitting in a therapist’s office. That’s part of why I became a running coach.

I’ve seen firsthand how running can be a lifeline for anxiety relief, both in myself and in the runners I coach.

Why Does Anxiety Feel So Overwhelming?

Before we get into how running helps, it’s helpful to understand what we’re up against.

If you’ve ever had anxiety, you know it’s more than just “worry.” Anxiety is an all-consuming experience that takes over both your mind and body.

When I felt anxious, it wasn’t just my thoughts racing – my body felt it too. My heart would thump in my chest, my breath would get shallow, and my muscles would tighten like I was bracing for something bad to happen.

This is what we call the “fight or flight” response.

It’s your body’s way of preparing to face a threat, even if that threat is something small, like being late to a meeting or having an awkward conversation.

In a way, anxiety is just your survival instincts working overtime. The same adrenaline rush that could save you if you encounter a predator is triggered by everyday stresses.

Our ancestors survived by fighting or running from danger, but today’s stresses (like social pressure or work deadlines) don’t require running from a saber-toothed tiger.

So that pent-up energy has nowhere to go. You’re stuck in a high-alert state, unable to release the tension. That’s why anxiety can feel so overwhelming – your body is ready to fight or run, but you’re standing still, mentally overloaded, and physically tense.

For me, understanding this was a breakthrough moment. It helped explain why I felt better after a run. By running, I was giving my body the release it desperately needed. I wasn’t sitting still with those nervous jitters anymore. I was moving, sweating, and letting my body do what it was built to do when stressed: get rid of that anxious energy.

And there’s some science behind it too. When you exercise, you’re completing the stress response cycle.

In simple words: when you’re anxious, your body is preparing you to fight or flee.Until you do, your body stays on high alert.

But once you actually go for a run (essentially “fleeing” in a healthy way), the body gets the message that it’s safe to relax. In my life, running became that healthy escape my body needed to calm down from that anxious high.

The Science: How Running Eases Anxiety

Alright, I’m a coach, not a scientist, but I’ve made it my business to figure out why running does wonders for my mental health. And here’s the thing—it’s not just in our heads.

There’s actual science behind why running eases anxiety, and knowing this helps me feel better about recommending it to my athletes.

Trust me, when you lace up and hit the pavement, real magic happens.

Here’s why running helps relieve anxiety:

It Triggers Calming Brain Chemicals

You’ve probably heard of endorphins—the “feel-good” hormones released during exercise. They’re the ones that give you that “runner’s high” and make you feel euphoric.

But get this—recent research suggests the real anxiety-fighting champion could be something even more powerful: endocannabinoids.

These are cannabis-like chemicals that our bodies produce naturally. When you run, you get a surge of endocannabinoids that can cross into your brain, helping to calm things down and reduce anxiety.

Basically, your brain gets drenched in a mix of anti-anxiety chemicals like endorphins, endocannabinoids, serotonin, and GABA—all working together to lift your mood and relax you. (I know it sounds like a lot, but trust me, it’s all good!)

According to Harvard Health, serotonin is the mood stabilizer many anxiety meds target, and GABA is like your brain’s natural chill pill.

It Burns Off Stress Hormones

Stress hormones like adrenaline and cortisol can make anxiety feel like an out-of-control engine. When you’re stressed, your body pumps out these hormones, and they keep you on edge.

But when you run, you’re burning through these stress hormones.

Running helps lower adrenaline and cortisol levels in your body, which helps you calm down. For me, it’s like I’m literally sweating out the cortisol that built up during a stressful day. And as Harvard Health points out, aerobic exercise is key to reducing these stress hormones.

It Relaxes Muscle Tension

If you’ve ever noticed your neck getting stiff or your jaw clenching when you’re anxious, you know that anxiety lives in your muscles. Running acts like a natural muscle relaxant.

When you get moving, your muscles burn energy, then release tension. After a run, I often feel physically looser and lighter—it’s that muscle tension melting away.

And research backs this up: exercise helps relax your muscles and clears stress-related chemicals from your bloodstream. Your body’s more relaxed, and it sends a signal to your brain that things are okay, interrupting the cycle of anxiety.

It Engages Your Flight Instinct in a Healthy Way

This one’s a bit more of a theory, but it rings true for me—and many other runners. Think about that fight-or-flight response we all experience when anxiety strikes.

Running is like a safe outlet for that “flight” instinct. When I start to feel panic—my heart racing, chest tightening—I go for a run. It’s like I’m giving my body the action it craves, and in return, it calms down.

One study even compared exercise to exposure therapy for panic because it helps you get used to physical symptoms like heart pounding and sweating in a safe way. Over time, those sensations become normal, and you don’t panic anymore.

It Boosts Your Brain’s Resilience

Here’s where it gets wild: regular running doesn’t just change your mood for the day; it actually changes your brain.

Cardio, like running, stimulates neurogenesis—the growth of new brain cells, especially in the hippocampus, which is key for mood and memory regulation.

Some of these new cells even release GABA, the calming neurotransmitter. Princeton scientists found that mice who ran regularly had brains that handled stress better because their new neurons helped them calm down faster.

So, running literally builds you a mental buffer against anxiety.

Plus, running increases blood flow and oxygen to the brain, and it even triggers BDNF (brain-derived neurotrophic factor), which helps protect neurons from damage.

Long story short? Running makes your brain more resilient to anxiety over time.

It Activates the Happy Part of Your Brain

When we’re anxious, our brain’s amygdala—the fear center—fires off like crazy. Running helps engage the prefrontal cortex, the part of the brain that can tell the amygdala to chill out and stop overreacting.

Think of it like this: the prefrontal cortex is the wise coach telling the amygdala, “Hey, it’s not that serious.” Over time, running helps you train your brain to handle stress better.

In fact, studies have shown that active people have better control over their stress response than those who don’t exercise. Running helps me “train my brain” just as much as I train my body.

Better Sleep (and More Stable Mood)

Anyone who’s dealt with anxiety knows how sleep and stress go hand in hand.

When you’re anxious, it’s hard to sleep—and when you’re tired, it makes anxiety worse.

But here’s the good news: running helps you sleep better. And I can tell you from experience: on days I run, I sleep like a rock. On days I don’t, I toss and turn.

Better sleep means a calmer mind the next day. If running helps you sleep, it breaks that vicious cycle of sleep-deprived anxiety.

That’s a lot of science, but here’s the bottom line: running is like a natural, all-in-one anti-anxiety treatment.

It releases mood-boosting chemicals, burns off stress hormones, relaxes muscles, and even helps rebuild your brain to better handle stress. And the best part? It works right away, but the benefits keep building over time.

You’ll notice a mood boost within minutes of starting a run (usually after about 10–20 minutes, I get that “Ah, I’m okay” feeling).

Research even shows that just 5 to 10 minutes of moderate exercise can improve your mood and reduce anxiety—so you don’t need to run for hours to get the benefits.

One study even found that people who were more physically active had better protection against developing anxiety than those who weren’t as active. So yeah, running is armor against anxiety. Some studies even suggest that exercise can be just as effective as medication or therapy for managing anxiety—though I’m not saying you should toss your meds just yet. More on that later.

One of the coolest things I’ve learned is that even a 10-minute walk can be as effective as a 45-minute workout in relieving anxiety. So, you don’t have to train for a marathon to feel better—just getting out there for a quick run or walk can make a huge difference.

Okay, now I want to hear from you: what’s your go-to way to beat anxiety? Drop a comment and let’s talk about how running helps you, or if you’ve got other ways that work!