How to be more explosive: rate of force development for sprinters

What rate of force development means

On a graph of force against time as you push into the ground, maximal strength is the highest point of the curve and rate of force development is how steeply the curve climbs. Two athletes with the same squat can have very different slopes.

The classic study here is Per Aagaard's from 2002. Fifteen men did 14 weeks of heavy strength training (38 sessions). Their maximal knee-extension strength rose about 16%, and their RFD rose by roughly 17 to 26% depending on the time window measured. The electrical activity in their muscles at the start of the contraction rose sharply as well, which the authors read as a stronger “neural drive” from the nervous system.

A 2016 review led by Nicola Maffiuletti, with Aagaard among the authors, explains where that signal fits in. The first 50 to 75 milliseconds of an explosive contraction depend mostly on how fast your motor units fire. Later in the rise, the size and strength of the muscle take over. The same review found that elite sprinters and jumpers develop knee-extensor force much faster over the first 150 milliseconds than active people of the same age.

Where it shows up in a sprint

Your foot spends longer on the ground in the first steps of a sprint and less as you speed up. A study that tracked sprinters step by step over 50m found support time falling while step length and flight time grew through the whole acceleration. By top speed, elite sprinters are on the ground for around 100 milliseconds, according to Haugen and colleagues' review of elite sprint training.

Aagaard's paper puts the window where RFD matters at 0 to 200 milliseconds. Every sprint contact fits inside it. Faster runners reach higher top speeds by applying more force to the ground, and their legs swing through the air at about the same speed as slower runners' legs. With so little time on the ground, more force per step has to come from building force faster, which is what rate of force development measures.

The link holds over short distances too. The Maffiuletti review describes elite rugby players with high RFD covering 5m in under a second, while teammates with lower RFD took a second or longer.

Heavy lifting raises the ceiling

Heavy strength training improves RFD as well as maximal strength, and it mainly lifts the later part of the force curve. A meta-analysis of strength training and sprinting found that gains in squat strength carried over to faster sprinting, with an average improvement of about 3%.

How strong you already are changes the priority. A 2018 review of strength training recommends that weaker athletes build strength before emphasizing power-type training, and that stronger athletes begin to emphasize power while maintaining or improving their strength. If you are new to the weight room, build your strength first and add the fast work as you get stronger.

Ballistic work and Olympic lifts

Ballistic exercises are ones where you accelerate the load all the way through and let it go: jump squats, med ball throws, trap-bar jumps. The Haugen review describes loads up to about 60% of your one-rep max as a potent stimulus for maximal power, with heavier loads needed to build the force side.

How fast you try to move the bar changes the result. In a 2025 study of 20 elite athletes who were already strength-trained, one group lifted with maximal intended velocity for 4 weeks and another lifted at moderate speed. Both groups got stronger. Only the fast group improved RFD relative to their strength, and the moderate-speed group's relative RFD fell by 15%. Try to move every rep as fast as you can, even when a heavy bar is moving slowly.

Olympic lifts are ballistic by design. The 2022 meta-analysis found that weightlifting training improved jump height more than traditional strength training, and it matched plyometrics for gains in sprint speed and power. Elite sprint programs use the snatch and the clean alongside squats and single-leg work, according to the Haugen review. If you haven't been coached on the lifts, the meta-analysis suggests plyometrics give you similar gains in sprint speed.

Plyometrics teach short, stiff contacts

Plyometrics train the fast stretch-and-rebound you use on every sprint step. A meta-analysis of 26 studies found that plyometric training improves sprint performance, and programs that mixed jump types and included horizontal jumps did best. The Haugen review advises sprinters to focus on leg stiffness and short ground contacts during plyos. It notes that the Italian sprinter Pietro Mennea's horizontal jumps and skips never exceeded 100 milliseconds of contact, close to elite sprint contacts at top speed.

The plyometrics for sprinters guide builds from pogo hops and bounds up to hurdle hops and depth jumps, with doses for each.

A sample week

This week follows the high/low pattern of Sprint University's base program. The sprint and jump doses come from its first two weeks. The lift goes after the sprints on the acceleration day, because the program never pairs heavy squats or deadlifts with max-velocity sprinting.

Every jump and throw is a full effort with full rest, and every set ends when the distance or height drops. The speed training guide explains how the high and low days are spaced and how the lifting changes over six weeks. To check whether any of it is working, time your 100m and compare it on the average 100m times page.

Common mistakes

Lifting fast loads slowly

Moderate-speed lifting lowered relative RFD in the 2025 study. Move every rep as fast as you can, and end the set when the bar slows from rep to rep.

Only lifting heavy

Heavy work raises your peak force. Add jumps, throws or ballistic lifts so you also reach force quickly.

Jumping tired

Plyos after a hard lift or a long sprint session turn into slow, long contacts. Jump fresh, then lift.

Skipping the sprinting

Heavy, vertical lifting does not automatically turn into horizontal force on the track. The Haugen review notes the odds of transfer improve when you combine strength and sprint training.