Contrast training: how it works and how it raises your vertical jump

Contrast training is a system that alternates, inside the same set, a heavy loaded exercise and an explosive bodyweight exercise. First you squat heavy, then you jump. The idea is to use the activation left behind by the load to jump higher in the next exercise, and over time to teach the nervous system to recruit fibres faster. You'll find it under the names contrast training or french contrast method.

What post-activation potentiation really is

When you push a load close to your max, the nervous system raises the activation level of the muscles involved. That activation doesn't vanish the second you rack the bar: it hangs around for a few minutes. If you jump inside that window, you start from a neurally "warmer" state than usual.

This is called post-activation potentiation (PAP). It isn't magic and it doesn't always work: it lives alongside the fatigue produced by that same heavy load. Rest too little and fatigue wins and you jump worse. Rest too long and the effect has already faded. For most athletes the useful window sits between two and four minutes, but it varies person to person: the stronger you are, the later your peak arrives.

What a contrast set looks like

The basic structure is simple: heavy load, short pause, explosive movement, long pause, start again.

1. Barbell squat — 3 reps around 85-90% of your max, clean, no grinding.
2. 15-30 second pause — the time it takes to rack the bar and get set.
3. Maximal vertical jump — 4-5 reps, every one at 100%, standing or with an approach depending on your goal.
4. Full 2-3 minute recovery before the next set.
5. Repeat for 3-4 sets total.

The French version (french contrast) adds two steps: after the heavy lift and the jump it slots in a plyometric exercise and finally an assisted or very lightly overloaded movement. Four exercises back to back, one block. It's very effective and it's also very demanding: it only makes sense if you already have a solid strength base.

The detail almost everyone gets wrong

The jump after the heavy lift isn't "some jump to round off the set". It's the part that matters most. If you do it tired, soft, with no intention of getting as high as you can, you're just piling up fatigue. Four jumps done properly beat ten done for the sake of it.

Who it's for and who it isn't

Contrast makes sense if you already have a strength base. If your squat is still light relative to your bodyweight, the "heavy" load doesn't produce enough activation and the session becomes a complicated way to do a few jumps. In that case you're better off building maximal strength first with classic weight room work, and moving to contrast a few months later.

It does make sense if:

• you train a sport where the jump or the sprint decides plays: volleyball, beach volleyball, basketball, track and field;
• you already have strength in reserve but feel "slow" in the explosive movement;
• you're at a point in the season where you want to turn built strength into power you can actually spend on court.

Frequency and where it goes in the week

Two sessions a week is more than enough. They go at the start of training, after the warm-up and before any endurance work: contrast needs a fresh nervous system. Don't put it the day before an important match and don't stack it onto a week that's already full of games.

Warm-up: not optional

Before you load 85% you need ankle and hip mobility, glute and calf activation and a few progressive sets on the movement you're about to use. Skipping the warm-up in a contrast session is the fastest way to get hurt.

Measure first, train, then measure again

Contrast is a conversion method: it takes the strength you have and makes it faster. To know whether it's working you need a starting number, otherwise you're going on feel — and feel, after six weeks of training, lies almost every time.

On the site there's a free jump test: you upload a two-second video of yourself jumping and the system calculates the height in centimeters from flight time. The video never leaves your device. Take the test before you start the block, write the number down, and redo it at the end. That way you know whether the method is paying off for you, not in theory.

The JHP programs that use contrast

If you want to apply it without having to build loads, rests and progressions yourself:

• JHP Contrast Method — €90. The plan built around contrast training: sequences already assembled, loads and rests given session by session, video for every execution.
• JHP Gym Edition — 16 weeks in the weight room, €60. This is the one to do first if you're still short on maximal strength.
• JHP Vertical Upgrade — 36 sessions across 12 weeks, €67.
• Every plan is listed on the JHP courses page.

Alternatively, the JHP subscription at €99/year includes all 13 programs, WhatsApp support and free cancellation.

You might also like: How to increase your vertical jump with the French Contrast Method · Why the gym belongs in your sports routine