You can't train hard every day

In partnership with

DEEP DIVE

Most sprinters understand that running fast requires hard training.

What fewer athletes grasp is that trying to train hard every day is the fastest way to stop getting faster.

Sprint training operates on a principle that feels counterintuitive to competitive athletes: some days need to be deliberately easy.

Not because you're soft or avoiding hard work, but because of what happens inside your body when you sprint at maximum effort.

When you run a true maximal sprint, you're not just getting tired. You're depleting the ATP and creatine phosphate stored in your muscle cells. You're asking your nervous system to coordinate thousands of muscle fibers in precise sequences. You're generating ground forces that create significant stress on muscles and connective tissue.

All of this requires real recovery time. Not just a day off, but actual structured training at lower intensities that helps your body adapt.

This is where high-intensity and low-intensity training come in.

High-intensity sessions are what most people think of as "real" sprint training. Maximum effort sprints. Explosive plyometrics. Heavy resistance work. Anything performed at 90-100% of your capability.

These sessions develop speed, power, and explosiveness. They create the specific adaptations that make you faster.

But they also hammer your central nervous system and create tissue damage that requires 48-72 hours to recover from properly.

Low-intensity training looks completely different. Tempo runs at 75% effort. Pool workouts. Light resistance work. The intensity is deliberately submaximal, and the purpose isn't to develop speed directly.

Instead, these sessions promote recovery while building aerobic capacity and work capacity. They keep you training without creating the neural fatigue or tissue stress that would compromise your next high-intensity session.

The research on this is pretty clear. Your ATP-CP energy system, which fuels maximal sprinting, needs substantial time to replenish after hard efforts. Studies suggest roughly 60 seconds of rest for every 10 meters you sprint at 100% effort.

That's just within a single training session.

Between sessions, the nervous system needs even longer. When you don't give it adequate recovery, your muscle contraction rates get dampened. Stride frequency drops. Technical quality degrades.

You might still be working hard, but you're no longer creating the stimulus that actually makes you faster.

This is why sprint programs alternate high and low-intensity days throughout the week. It's not about being cautious or holding athletes back. It's about respecting what the body needs to adapt.

Most programs prescribe 2-3 high-intensity sessions per week, never on consecutive days, with low-intensity work filling the gaps.

The pattern might look like high on Tuesday, low on Wednesday, high on Thursday, low on Friday. Or high on Monday and Wednesday and Friday, with low-intensity sessions on Tuesday and Thursday.

The specific arrangement varies, but the principle stays the same: adequate recovery between maximal efforts.

What makes this difficult for competitive athletes is the mental challenge of constraining effort during low-intensity sessions.

When you're wired to compete and push yourself, running at 75% effort feels wrong. It feels like you're leaving something on the table or not maximizing your training time.

But that's exactly the point.

Low-intensity training only works if you actually keep the intensity low. Pushing tempo runs into threshold zones or treating recovery sessions like competitions defeats the entire purpose. You end up creating additional fatigue without the benefits of true high-intensity work.

The discipline required to train easy on easy days is often harder than the discipline to train hard on hard days.

From my experience coaching groups, this is where most athletes struggle. They understand high-intensity work intellectually. But executing genuinely submaximal training goes against every competitive instinct they have.

The athletes who figure this out tend to be the ones who keep improving over multiple seasons. They learn that productive training isn't about crushing yourself every session. It's about creating the right stimulus at the right time and allowing adaptation to occur.

Both high-intensity and low-intensity training serve essential purposes in sprint development. Neither can replace the other.

High-intensity work provides the stimulus for speed improvement. Low-intensity work creates the foundation that allows you to execute high-quality training consistently without breaking down.

Strip away either component and the system falls apart.

Try to train hard every day and your quality deteriorates. Skip low-intensity work entirely and you lose the aerobic base and work capacity that supports sustained high-level training.

The alternating model works because it acknowledges a fundamental truth about human physiology: adaptation occurs during recovery, not during the training session itself.

Your job during high-intensity training is to create a stimulus strong enough to trigger adaptation. Your job during low-intensity training is to facilitate that adaptation while maintaining training frequency.

Over the next two weeks, I'll break down what each type of training actually accomplishes and how to execute both properly. But the foundation is understanding why you need both in the first place.

You can't just train hard all the time because your body doesn't work that way.