Interval Training Mistakes (And How to Fix Them Without Wrecking Your Progress)
Interval training works — no doubt about it.
But only if you don’t sabotage yourself.
I’ve coached runners for over a decade, and I’ve messed up plenty myself.
The truth? Most people don’t screw up because they’re lazy — they mess up because they’re either too eager or just following bad advice.
So here’s the no-fluff breakdown of the biggest interval training mistakes I see over and over…
and how to fix them before they derail your gains.
1. Blasting Out Too Fast (aka The Crash-and-Burn Special)
This one’s at the top for a reason.
Too many runners treat the first rep like a 100m sprint — all out, no control — then wonder why they’re dragging through the rest.
That “fly and die” routine? It kills the purpose of the workout.
You spend less time in the right pace zone and more time just surviving.
I’ve seen it a hundred times. Heck, I’ve done it.
You nail the first 400m feeling like a beast, then by rep #5, you’re bargaining with your watch and praying for mercy.
The Fix:
Start smarter. Lock in on consistent pacing.
Slight negative splits are gold — finish strong, not crawling.
If your workout says 8×400m at 90 seconds, stay within 1–2 seconds of that target.
If your first rep clocks in at 1:20, that’s not “crushing it” — that’s ego.
Save the hero pace for race day.
💬 What’s your go-to pacing trick for intervals?
2. Messing Up Recovery (or Just Skipping It Altogether)
Some runners rush through recoveries like it’s a punishment. Others jog so slow it looks like a zombie shuffle.
Neither works.
Recovery is part of the workout — not a breather, not a nap, but a reset so you can hit the next rep hard.
Coach Matt Fitzgerald put it best:
If you can’t hold your planned recovery pace toward the end, your intervals were too aggressive. Period.
The Fix:
Use the recovery wisely. A slow jog or brisk walk works.
You don’t need to feel fresh — just fresh enough.
Rule of thumb:
Aim to feel 50–70% recovered before the next rep.
If you start needing to walk all your recoveries when you planned to jog, either ease up the pace or extend your recovery a bit.
Recovery isn’t weakness — it’s strategy.
💬 Do you jog, walk, or pray during your recoveries?
3. Skipping the Warm-Up (Then Wondering Why You Pulled a Hammy)
This one still baffles me.
Runners jump out of the car, slap on a watch, and start sprinting like they’re late for a flight.
That’s not training — that’s begging for injury.
I’ve had runners message me asking why their hamstrings felt tight mid-workout…
and when I ask if they warmed up, it’s crickets.
The Fix:
Always. Warm. Up.
Start with 5–15 minutes of easy jogging, toss in some leg swings, high knees, and a few strides.
You want to break a sweat before you break the speed barrier.
If your first rep feels stiff, hit pause, loosen up, then go again.
💬 How long do you usually warm up before speed work? Be honest.
4. Doing Too Much, Too Soon (aka The “More Must Be Better” Trap)
I love enthusiasm. I do. But interval workouts are not all-you-can-eat buffets. I’ve seen runners copy elite workouts like 10×800m before they’ve even mastered 4×400m. The result? Sore legs, zero progress, and sometimes injury.
The Fix: Respect where you’re at. Start with just one interval session a week. Keep total speed work volume reasonable — about 2 miles’ worth for newbies, 4–5 miles for experienced folks. Give yourself 48+ hours between hard sessions. This stuff builds over time — not overnight.
Back when I started, I thought doubling the reps would get me fitter faster. It didn’t. It got me benched with an overuse injury.
💬 Ever overcooked a workout thinking it would give you superpowers? What happened?
5. Letting Form Go to Trash Mid-Workout
When the pace gets spicy, form often goes out the window. I’ve seen runners flailing their arms like they’re in a mosh pit, overstriding, and tightening every muscle like they’re trying to squeeze out more speed with their face.
But bad form during speed work = reinforcing sloppy mechanics = higher injury risk. Not worth it.
The Fix: Do mental form checks mid-rep. Ask yourself: “Are my shoulders relaxed? Is my stride short and snappy? Am I landing under my body?” Keep your arms compact. Run tall. If your form falls apart, slow down a little — not a full gear shift, just enough to run smooth again. Good mechanics at 90% is more useful than ugly effort at 105%.
And if you really want to improve form? Add strides on your easy days. They teach you how to move fast without falling apart.
💬 What’s your go-to form cue when things get messy mid-interval?
Don’t Be a Slave to the Watch (Or Blind to It Either)
Here’s the deal: some runners go into intervals completely winging it—no timing, no pacing, just vibes. Others? They obsess over their splits like their life depends on hitting that exact 400m time. Both camps run into trouble.
If you’re not paying attention to pace at all, you might be running way too easy or redlining without knowing it. On the flip side, if you’re glued to your watch every rep, freaking out over a few seconds, you’ll stress yourself into burnout.
My advice: Use the watch smartly. Check your first rep to see where you’re landing. That’ll help you calibrate. But don’t panic if one split’s off because of wind, fatigue, or a hill. Conditions change. So should your expectations.
I once coached a guy who trained purely by feel, no watch. He swore it made him “free.” Turns out, he was running his intervals slower than his long runs. No joke. Freedom’s great, but structure still matters.
Chasing Intervals but Skipping the Meat
Intervals are exciting. They make you feel fast. They give you numbers to chase. I get the thrill—I’ve been there. But here’s a mistake I see way too often: runners falling in love with speedwork and ditching everything else.
I’ve seen runners bang out 3 speed sessions a week, no easy runs, no long runs, just high-octane grind. Then they hit a wall—either they stop improving or end up sidelined.
Someone on Reddit once said they were doing up to 10×800m during marathon prep—and saw zero benefit. Honestly? Probably because they didn’t have the endurance base to support that kind of work. Intervals without aerobic support are like trying to build a house on sand.
The fix: Use intervals as seasoning, not the whole meal. You need easy runs to build your base, long runs for stamina, and maybe some tempo work to hold steady effort. Intervals are the final touch—the sharpener. Not the engine.
If your interval times aren’t budging, or they feel harder than they should, it might be time to back off the repeats and put more time into base miles or threshold work.
Recover Like It Matters—Because It Does
You can nail the session, but if you skip recovery, it’ll come back to bite you.
I’ve had stretches where I crushed my workouts… and then stayed up till 2 a.m., barely ate anything after, and got lazy with the foam roller. Not surprisingly, I felt like trash two days later.
Intervals are hard. They stress your body. That stress only turns into gains if you give it time and fuel to rebuild.
So here’s your job after intervals: Drink water, get in some carbs and protein, maybe a short stretch or light mobility later that evening. And sleep—good sleep. It’s not optional.
Also, check in with your mind. If you’re dreading interval day to the point of panic, something’s off. Maybe you’re overcooked. Or you’re pushing every session like it’s race day. Pull back. Not every session has to wreck you.
Final Thoughts: Run Smart, Not Just Hard
Intervals should challenge you—but they shouldn’t break you. When done right, you’ll finish tired but proud. Done wrong, you’ll leave the track frustrated, or worse, limping.
Remember: every rep should have a reason. If you’re just going through the motions, it’s time to reassess. Training isn’t just about grinding—it’s about smart execution.
Some runners can handle two interval sessions a week. Others? One is more than enough. Learn what works for you. Your body will tell you—if you’re willing to listen.
Even as a coach, I catch myself going out too hot on the first rep just because my ego’s feeling spicy. We all make mistakes. What matters is learning from them and dialing things in.
Bottom Line:
Interval training is one of the best tools in the toolbox — but like any tool, it works best when used with some know-how. Don’t just run hard. Run smart.
Train with purpose. Rest with intention. And stay honest with yourself — because running doesn’t lie.
Let’s open it up:
What’s the biggest interval mistake you’ve made? How did you fix it? Drop a comment and let’s trade war stories. #intervaltraining