Ever been cruising along mid-run, feeling good, and then bam—your heart does something funky?
Like it skips, flutters, or thuds hard enough to make you stop and go, “What the hell was that?”
First—don’t panic.
Most heart palpitations (that sudden flutter, flip-flop, or pounding thud) are common, especially in runners.
And they’re usually no big deal.
Running naturally revs up your heart—that’s just cardio doing its job.
But if your heart throws in an extra beat or two, or you feel it stumbling around like it forgot the rhythm, it’s time to tune in and pay attention.
Think of this as a no-BS coaching session.
I’m not a doctor (just a dude who’s been scared straight by a heartbeat), so if you’re getting these flutters regularly, go see a pro.
But I have dug into the research, and I’ve talked to plenty of runners who’ve been there too.
So here’s the deal: most of the time, a few basic fixes—better hydration, dialing back the caffeine, not hammering every run like it’s race day—can settle things down.
But I’ll also help you spot when it’s time to stop brushing it off and get checked out.
What the Heck Are Heart Palpitations, Anyway?
Okay, so let’s break it down: a heart palpitation isn’t just your heart beating fast—that’s normal when you run.
It’s when the beat itself feels off. Like it skips, pounds too hard, races out of nowhere, or does this weird hiccup thing.
You might feel it in your chest, neck, even your throat.
Technically, it’s often caused by what docs call premature contractions.
The most common is a PVC—premature ventricular contraction.
Fancy name, simple idea: your heart sneaks in an extra beat, then thumps hard on the next one.
Feels like a skip followed by a punch. Freaky—but if it happens once in a while and you’re healthy? Usually no biggie.
Here’s the thing: when you’re out there grinding up a hill and your heart’s pounding like a bass drum, that’s not a palpitation—that’s normal.
Your body’s just delivering the goods (oxygen, blood, power) to your muscles. You should feel your heart working.
Palpitations are different.
They usually show up when you’re chilling mid-run, or even during your cooldown.
You’re expecting smooth and steady—and suddenly it’s jazz.
Out of rhythm. Like a drummer who lost the beat.
For context, normal resting heart rate for adults is around 60–100 bpm.
If you’re in solid shape, it could be way lower—mine sometimes dips into the high 40s after a strong training block.
During moderate workouts, 120–160+ bpm is totally fair game.
But again—palpitations are about rhythm, not speed. It’s the pattern that gets wonky.
A 40-year-old, for example, might peak at around 180 bpm (220 minus your age—a rough formula, but a decent guide).
You’ll feel the thump when you’re pushing hard—but if your heart randomly lurches while jogging at an easy pace or throws a fit while cooling down?
That’s when the quiet alarm bells start ringing.
Now here’s the good news: research shows that most of these little heartbeat hiccups are harmless, especially in runners who are otherwise healthy.
The Journal of Strength & Conditioning Research has found that endurance athletes often experience benign palpitations that go away when they rest, rehydrate, or simply stop stressing out. No ER trip needed.
Still, you’ve got to pay attention. If it’s just one flutter and you feel fine? Probably nothing to stress over. But if it comes with dizziness, shortness of breath, or pain? That’s a red flag. And we’ll cover exactly what to look for in the next section.
When It’s Not Just Nerves—Take This Seriously
Look, most of the time, heart palpitations are not some serious running injury—like your ticker trying to throw a rave for no reason. Annoying, maybe even a little scary, but usually nothing to panic about.
But sometimes? They’re a big red flag.
As much as I love to say “push through it,” this is one of those times where I’ll tell you to pull the plug and pay attention.
If you get any of the signs below while your heart’s skipping around like a jackrabbit, don’t tough it out—get checked.
These could mean you’ve got something serious going on with your heart’s rhythm, and that’s not something you can out-train.
1. Chest Pain or Pressure? Don’t Be a Hero
Feel tightness, pain, or that crushing elephant-on-the-chest thing while your heart’s flipping out? That could mean your heart isn’t getting enough oxygen. We’re talking ischemia—or worse.
2. Dizzy Spells or Blacking Out? Huge Warning Sign
If you feel like the floor’s moving or like you might faint—or if you actually do—your heart might not be pumping enough blood upstairs to your brain. And yeah, that’s bad.
Passing out (syncope) during or right after a palpitation isn’t just “a weird moment.” It’s a 911 moment.
3. Nearly Passing Out? Same Deal
Even if you don’t hit the ground, that “graying out,” cold-sweaty, tunnel-vision vibe is just as sketchy. It could mean your heart’s not keeping up, maybe due to an arrhythmia.
Either way, treat it like a big red stop sign.
4. Can’t Catch Your Breath?
Yeah, we all huff and puff on hills.
But if your heart’s going haywire and you’re gasping for air when you shouldn’t be—or you suddenly feel like you’re drowning in your own lungs mid-run—listen to your body.
Especially if your pulse feels totally out of control and won’t settle down even when you stop.
5. Heart’s Still Racing Long After You Stop?
It’s normal for your heart to keep pounding for a few minutes after a hard effort—but it should come back down.
If your heart’s still doing drum solos at 180+ bpm while you’re standing still? That’s not okay. Time to call the doc.
Why the Heck Is Your Heart Acting Up Mid-Run?
Let’s break down why this happens. No fluff. Just the real stuff, based on both the science and what I’ve seen in the trenches with runners of all levels.
1. Stimulants: The Sneaky Speed-Demons in Your System
Let’s talk about that magical cup of morning go juice—yeah, your coffee.
It might help you feel alive during that 6 AM run, but too much of it? Your heart’s not a fan.
Caffeine amps up adrenaline, and if you’re sensitive or just chugged a double espresso, it could throw your rhythm off.
According to research in the Journal of Strength & Conditioning Research, caffeine messes with heart rate and rhythm in susceptible folks—especially in combo with intense training.
Same goes for pre-workout powders, energy drinks, nicotine, and even chocolate (yep, theobromine is a mild stimulant).
Then there’s alcohol. Even though it’s technically a downer, too much can jack your heartbeat.
They even call it “holiday heart” when it kicks in after a few too many drinks.
2. Running on a Full Belly? Recipe for Heart Drama
Look, I love food as much as the next runner. But slam a big meal and dash out the door? Your heart’s gonna throw a fit.
Here’s what’s happening: after a heavy, greasy, or sugar-loaded meal, your body’s trying to digest.
That takes blood.
But your muscles also need blood when you run. So your heart ends up stuck between two bosses, trying to serve both. That tug-of-war can cause palpitations—and maybe some nasty cramping too.
High-sodium meals, MSG, nitrates (think hot dogs or processed junk), even spicy food? All have been linked to extra beats and fluttery heart stuff.
🕒 Rule of thumb: Wait at least 2–3 hours after a heavy meal to run. If you’re short on time, grab a banana, half a bagel, or an energy bar—something light that won’t throw your heart into chaos.
And if your go-to fuel includes tons of sugar? That insulin spike can set off adrenaline and get your heart racing before your feet even hit the road.
3. Dehydration: When Your Heart’s Working Double Overtime
Ever feel your heart thudding harder during a summer run? Like, louder than usual? Might not be your playlist—it’s probably dehydration.
When you’re running low on fluids, your blood volume drops.
Less blood = your heart has to beat faster to keep the engine going.
It’s like trying to water your lawn with a half-clogged hose. Not great.
And it’s not just about water—sweat steals electrolytes too, especially sodium and potassium.
Mess with those, and your heartbeat can get weird real fast.
Simple game plan:
- Drink water throughout the day—not just right before your run.
- About 30 minutes pre-run: sip 4–6 ounces.
- Going long or running in heat? Bring water or an electrolyte mix. Aim for a few ounces every 20 minutes. Adjust for how much you sweat.
4. Electrolyte Imbalances: The Hidden Saboteur of Your Heartbeat
Look, your heart isn’t just thumping away randomly—it’s running on an electrical system that’s wired up with electrolytes.
I’m talking sodium, potassium, magnesium, and calcium. These minerals?
They carry electric charges that literally keep your heart beating in rhythm.
When they’re off—either too low or too high—it’s like trying to run your GPS watch on a dead battery.
Your heart starts throwing in some weird beats, skips, or flutters.
Now, if you’re a runner, odds are you’re more likely to be on the low end.
Why? Because we sweat buckets. Especially in heat, or on those monster long runs.
And if you’re just downing gallons of plain water to rehydrate? You could actually be diluting the stuff your heart needs to function properly.
Sodium and potassium are the big players here. They’re the ones controlling the little electric switches in your heart muscle cells.
Magnesium and calcium back them up, helping keep the rhythm smooth and steady.
Drop any of these—like if you’re low on potassium (hypokalemia)—and boom: you’re twitchy, crampy, and possibly feeling like your heart’s doing the cha-cha.
Ever finished a long hot run and had your calves cramp up like crazy?
Or those annoying muscle twitches that hit when you’re trying to fall asleep?
That’s your body screaming for electrolytes. And yeah, your heart’s a muscle too—it can cramp in its own way.
Here’s the deal: if you’re training hard (especially in heat), get smart about your electrolytes.
A sports drink, salty snack, or a tablet in your bottle during long runs can go a long way.
Target: Aim for about 300–600 mg of sodium per hour of exercise—on the higher end if your face looks like a salt lick after a run. That’s a sign you’re a “salty sweater.”
- Potassium: Bananas, sweet potatoes, coconut water
- Magnesium: Dark leafy greens, whole grains, nuts, supplements if needed
- Calcium: Dairy, tofu, almonds
If your heart feels off, it’s worth getting a simple blood test.
Docs often check potassium and magnesium when you report palpitations. And the good news? If you’re low, it’s usually easy to fix with some dietary tweaks or basic supplements.
But careful: Don’t go rogue on potassium—too much can mess you up fast. But a banana or Gatorade? Totally safe.
Think of it like this: your electrolytes are the fuel for your heart’s spark plugs. Keep ‘em topped off.
5. High Altitude: Where Your Heart Gets Humbled
So you’re headed for the mountains? Maybe it’s a trail race or just a high-elevation training camp.
Whatever the reason, don’t freak out if your heart feels like it’s racing even when you’re walking to the start line.
That’s altitude doing its thing.
At higher altitudes—especially above 8,000 feet—oxygen gets scarce.
Your body’s smart. It goes, “Uh oh, we’re low on air,” and kicks the heart into overdrive.
Beats faster. Harder. Just to shove more oxygen around.
That pounding heartbeat? Totally normal.
And please don’t take my word for it.
Studies show your heart rate at high altitude is gonna spike—same effort, higher beats per minute.
So what do you do?
Adapt. Slowly.
- If you’ve got a race coming, get there early. Spend a day or two at moderate altitude first if you can.
- Sleep, hydrate, take it easy. The air’s dry up there—you lose more water just by breathing. So sip fluids, but don’t forget electrolytes too.
- Don’t expect sea-level pace. You’re not Superman. Scale it back and let your body catch up.
Over a few days, your body will start producing more red blood cells, which helps you adjust. Most runners settle in after 2–4 days.
6. Medications and Supplements – The Sneaky Saboteurs
Let’s get real for a second—sometimes your heart’s not freaking out because of your training or your diet.
Sometimes, it’s that innocent-looking stuff in your bathroom cabinet.
Yeah, I’m talking meds and supplements. These things can sneak up on you.
Take decongestants, for example. That cold medicine you grabbed with pseudoephedrine?
It’s basically a legal stimulant.
Same with certain asthma inhalers—especially the ones with albuterol.
They do their job, but they also rev your heart like you just slammed an espresso and started sprinting.
Even thyroid meds can mess with your rhythm if the dose is a tad too high. Your metabolism goes full throttle, and your heart follows suit.
And don’t even get me started on fat burners or diet pills. A lot of that junk is loaded with caffeine, yohimbine, or other lab-sounding ingredients.
I tried a so-called “natural” fat burner a few years ago—my heart was pounding like I was mid-race, and I was just sitting in traffic. Never again.
According to the Journal of Strength & Conditioning Research, even some antibiotics and antifungals can throw off your rhythm—rare, but it happens.
And if you’re popping herbal supplements thinking “natural means safe,” think again. Bitter orange (common in weight-loss stuff) and licorice root have both been tied to palpitations.
Rule of thumb: If you start something new—med, vitamin, herb—and suddenly your heart’s doing the jitterbug, it’s not a coincidence. Talk to your doc or pharmacist.
Pro tip:
- If you’re on thyroid meds, asthma inhalers, or anything else with a heart-boosting side effect, stick to the lowest dose that still works.
- Don’t mix pre-workouts with cold meds and expect your heart to be cool with it. That’s like lighting a match on a gas grill and hoping it doesn’t flare.
And yes—let’s not ignore the elephant in the room.
Recreational drugs? Massive red flag. Cocaine, amphetamines, even weed in some people, can wreck your heart rhythm.
You’re already putting enough pressure on your ticker with training—don’t throw fuel on the fire.
7. Overtraining or Going Too Hard, Too Fast
Okay, now we’re getting into classic runner territory—the “I thought more was better” trap.
We’ve all been there.
You start feeling strong, so you add more mileage, throw in extra speedwork, skip a rest day here and there… until your heart starts tapping out weird signals.
When you’re training too hard without enough recovery, your nervous system gets stuck in fight-or-flight mode. You feel wired, maybe anxious. Resting heart rate climbs. HRV tanks. Cortisol shoots up. Basically, your body’s yelling, “Dude, chill!”
Here’s how I’d recommend you to do:
- Increase gradually. That old 10% rule is a decent baseline, but if you’re fried, even that’s too much.
- Mix intensity wisely. Keep HIIT and hill sprints occasional, not daily.
- Rest days are non-negotiable. Your body repairs on the couch, not during the run.
- Use wearables. A spiked resting HR or tanked HRV? Back off.
Respect the Long Game
Your heart is a tough, amazing muscle. It’ll adapt and get stronger with training—but it needs respect, too.
Don’t trash it by ignoring fatigue or thinking rest is weakness.
Research even shows that lifetime endurance athletes (think Ironman diehards) have 2–10x higher rates of atrial fibrillation.
Not a reason to quit running—but a reason to stay balanced.
Listen to the Body—It’s Always Talking
Here’s a little truth from the trenches: when I wake up feeling like I’ve been hit by a truck, I don’t train hard.
That’s not weakness—it’s being smart.
Fatigue, stress, and bad sleep gang up on your nervous system and invite palpitations to the party.
My best advice?
Get yourself a heart rate monitor or smartwatch. Check your resting heart rate (RHR) in the morning.
If it’s 5–10 beats higher than usual, that’s your body whispering: “Not today.”
If you track HRV and see a nosedive, keep it chill. No hero workouts on days your system’s down.
Don’t Just Run—Train Like a Full Athlete
Look, if all you do is hammer miles every day, even the strongest heart’s gonna grumble.
Mix it up.
Bike. Swim. Hike. Walk the dog fast enough to break a sweat. That’s cross-training gold right there.
And strength training? Don’t skip it.
Lifting doesn’t spike your heart rate like cardio, but it makes your running more efficient.
I’ve seen it time and time again—runners who lift run smoother, stronger, and with less cardiac strain at the same pace.
When It’s Time to Call the Pros
Now, if you’ve done all the above—hydrated, cut back caffeine, trained smart, slept well—and your heart’s still fluttering like it’s in love with your shoes, it’s time to loop in a doc.
Palpitations hitting daily? Feeling faint, dizzy, or tight in the chest? Don’t wait it out. Get it checked. Here’s what the medical side usually looks like:
- Resting ECG: Quick in-office test. Might catch an arrhythmia—or not. These things are sneaky, but it’s a solid starting line.
- Blood Work: Checks thyroid (overactive thyroid can spike heart rate), anemia, electrolytes, and inflammation markers.
- Holter Monitor: Worn for 24–48 hours (or longer with a Zio patch). Logs every beat—great if palpitations happen daily.
- Treadmill Stress Test: Wires you up and makes you run. Not fun if you’re nervous, but super revealing for how your heart behaves under load.
- Echocardiogram: Ultrasound that shows heart size, valve function, and pumping power. Useful for spotting hidden issues.
- Extra Testing (if needed): Tilt-table tests (for dizziness/passing out) or an electrophysiology study (mapping your heart’s circuits from the inside). Hardcore, but only if truly necessary.
Final Thoughts: Don’t Freak Out, But Don’t Shrug It Off Either
Let’s get one thing straight: almost every runner out there—me included—has felt their heart do something weird at least once.
Maybe it skips a beat after you push too hard on intervals. Maybe it flutters on a hot long run when you’re salty, sunbaked, and underfueled.
Most of the time? It’s nothing serious. But still, don’t brush it off. And don’t spiral into panic mode either.
But here’s the deal—don’t be a hero if something feels off. You can’t just grind your way through heart issues. If you’re feeling dizzy, get chest pain, or even if your gut just screams “not normal,” you’ve gotta respect that signal. Go get it checked.
Worst case, you catch something early and get the help you need. Best case? You get a clean bill of health and sleep better knowing your engine’s solid.
So here’s my call to you: be the kind of runner who listens to their body—not just their GPS watch. Build a running life that supports your heart. Hydrate, eat real food, cut back on the stress (yeah, easier said than done, but it matters).
Most palpitations will fade. And if they don’t? You’ve got science, doctors, and a game plan to help you move forward.
At the end of the day, strong runners aren’t just the ones who hit big mileage. They’re the ones who take care of their whole damn system. Your heart’s the engine. Listen to it. Take care of it. And it’ll keep you running strong for years to come.
What About You?
Ever had heart flutters mid-run? What did they feel like? How did you handle it? Drop your story—let’s talk. You’re not alone in this.