How heavy should a sled be for sprint training?

It depends on the goal, and the best measure is how much the sled slows you. Light loads of under 10% velocity loss keep your sprint close to normal. Loads that cut your top speed by about 50% train horizontal force for the first steps. In high school athletes, a 50% velocity loss took a sled pull of 71–107% of body mass and a sled push of 45–85%, so test your own load.

Is a sled push or sled pull better for speed?

Both have improved short sprints in research. A pull, in a harness, lets your arms swing and looks more like a sprint. A push, with hands on the poles, fixes your body angle and your arms. In one study of 50 high school athletes, all three sled-push groups improved 5–20m split times over 8 weeks, and unresisted sprinting did not.

Do sled sprints make you faster?

They improve acceleration. A 2018 meta-analysis found sled training improved early acceleration but not maximum velocity, and it was not clearly better than the same training without a sled. A 2024 meta-analysis found resisted sprinting improved 10m times more than normal sprinting, with no difference over 20m or at top speed.

Do heavy sleds ruin sprint technique?

Not in the studies so far. Heavy sleds change your stride while you pull them, with longer ground contacts and shorter steps. After 9 weeks of heavy sled training at loads near or above body mass, professional soccer players showed no meaningful long-term change in their unloaded sprint kinematics, and their 30m times improved.

How many sled sprints should I do?

One heavy-sled study used 10 × 20m twice a week for 8 weeks. As a supplement to free sprints, 4–8 reps of 10–20m is plenty for one session, with 2–3 minutes of rest. Sprint University's program uses about four light sled pushes of 10–20m after the day's sprints.

Sled sprints: how heavy, push vs pull, and sessions that work

By the Sprint University coaching team

A sled sprint is an all-out acceleration with a weighted sled, either pulled behind you in a harness or pushed in front of you by its poles. Light sleds keep your sprint close to normal. Heavy sleds that cut your speed by about half train the long, hard push of the first steps. Set the load by how much it slows you, since the same plates slow different athletes on different surfaces by very different amounts.

Sled training improves acceleration, and in pooled studies it beat plain sprinting only over the first 10m. Use the sled alongside free sprints.

What sled training does

Acceleration depends on how much force you put into the ground and how much of it points forward. The acceleration drills guide covers that research. A sled adds resistance, so you stay in the forward lean of the first steps for longer and push against more load on each one. Your speed stays low while your effort stays maximal.

The sled also changes your stride while you pull it. With heavy loads in one study, ground contact time rose about 28–40%, step rate fell about 15–17% and step length fell 11–22%. Lighter sleds change it less. That trade decides which load to use: light sleds for sprint-specific work, heavy sleds for force.

Sled push vs sled pull

The sled push most people know is the gym sled you lean into with both hands. Loaded with plates and pushed at walking pace, that is strength and conditioning work. Loaded so you can still sprint, it is a resisted sprint.

	Sled push	Sled pull
Contact	Hands on the poles	Waist belt or shoulder harness and a line
Arms	Fixed on the poles	Free to swing
Body angle	Set by the pole height and the load	Set by the load
Load for 50% velocity loss (high school athletes)	45–85% of body mass	71–107% of body mass
Best for	Team-sport acceleration, short pushes	Acceleration with your normal arm action

The two velocity-loss figures come from separate studies by the same group, with different athletes, so the loads aren't interchangeable. Test each sled on its own. Both kinds of sled have improved short sprint times in training studies.

How heavy should a sprint sled be? Light vs heavy loads

Researchers describe sled loads as a percentage of body mass or as the drop in top speed they cause (velocity loss, or velocity decrement). A 2016 systematic review grouped them like this:

Load	% body mass	Velocity loss
Light	Under 10%	Under 10%
Moderate	10–19.9%	10–14.9%
Very heavy	Over 30%	Over 30%

Older guidelines put sled loads at about 7–20% of body mass. Then Cross and Morin's group measured the load that maximizes power while sprinting with a sled: about 78% of body mass for recreational athletes and 82% for sprinters, and 69–96% depending on the surface friction. That is several times heavier than the guidelines, and the heavy-sled studies below train in that range.

Sprint University's program sits at the light end. It uses a sled of about 10–15% of bodyweight after the day's sprints and moves to about 20% later in the block. Heavy sleds are a separate tool.

How to set the load with the velocity-loss method

Body mass percentages are a poor guide on their own. In Cahill's study of 70 high school athletes pulling sleds, the load that caused a 50% velocity loss spanned 71% to 107% of body mass across athletes. Surface friction also changes how heavy a sled feels. Velocity loss measures what the sled does to you, on your surface.

Velocity loss	Sled pull load	Sled push load
10%	14–21% of body mass	Not tested
25%	36–53%	23–42%
50%	71–107%	45–85%
75%	107–160%	69–131%

Each range is the spread between athletes that the study reported. Use them as starting guesses, then test:

Measure your top speed in an unloaded sprint. A radar or laser gun is best. Timing gates or phone video over a marked 5–10m section near the end of a 20–30m sprint also works.
Run the same sprint with the sled at two or three loads, with full rest between. Measure your speed over the same section.
Plot speed against load. In both Cahill studies the relationship was close to a straight line for every athlete, so you can read off the load for any target.

If you only have a stopwatch or video, compare the time through the same section. A 10% speed loss makes that section take about 11% longer, a 25% loss about 33% longer and a 50% loss twice as long.

The Sprint University app

Acceleration sessions with or without a sled

Sprint University programs acceleration, top speed, speed endurance, plyos and strength week by week from your current times. If you don't have a sled, it gives you the hill or partner version.

Get Sprint University

What the research shows for resisted sprints

Reviews

A 2016 systematic review of 11 studies found that moderate to very heavy sled loads produced acceleration gains from trivial to extremely large (0.5–9.1%) in team-sport and strength-trained athletes. Whether sleds beat unresisted sprinting remained unclear. A 2018 meta-analysis of 13 studies found sled training improved the acceleration phase but not maximum velocity, and in studies with a control group, the sled groups did not improve significantly more. The biggest effects were in recreationally active or trained men from team sports such as football and rugby.

A 2024 meta-analysis of 21 studies came to a similar place. Resisted sprinting (sleds, parachutes, hills) was the only method that improved 10m times more than normal sprinting. For 20m times, maximum velocity and kinematics, normal sprinting did as well.

Heavy sled studies

Sixteen amateur soccer players trained for 8 weeks (16 sessions of 10 × 20m), with either a sled of 80% of body mass or no sled. The heavy sled group increased maximal horizontal force more (effect size 0.80 vs 0.20) and improved how much of their force pointed forward. Their 5m gains were moderate, against small gains in the control group.

In professional Finnish soccer players, sled groups trained at loads that cut their speed by 50% (about 94% of body mass, sled included) or 60% (about 120%). Over 11 weeks, 30m times improved 2.9% and 2.0%. The control team improved 1.2%, which was not significant. The players' unloaded sprint kinematics showed no meaningful change.

A pilot study in soccer and rugby players compared 12 sessions of 10 × 20m at a 10% velocity loss with the same at the power-optimal load (a 50% velocity loss). Both protocols improved split times by an average of 1.4–2.3%, and individual results varied widely.

Sled push in young athletes

Fifty high school athletes trained twice a week for 8 weeks with unresisted sprints or with a sled push set at a 25%, 50% or 75% velocity loss. All three sled groups improved their 5–20m split times, and the unresisted group did not. Gains were largest over the first 5m and in the heaviest group.

Taken together, sled training improves the first 5–10m, and heavy loads haven't damaged sprint mechanics in the studies so far. They have not clearly beaten plain sprinting over 20m or more, and they don't train top speed. A brief review of 48 studies, covered in the sprint workouts guide, found sprinting itself the most effective way to improve sprint times.

Sled sprint sessions

This is the first acceleration session of Sprint University's base program, with a light sled:

Week 1, day 1 · Acceleration

Acceleration + Sled

High day

Block	Prescription
Track warm-up	15 min: easy jog, dynamic drills, build-ups
20m sprints	4 × 20m @ 98–100%, rest 2 min
30m sprints	2 × 30m @ 98–100%, rest 3 min
40m sprint	1 × 40m @ 95–100%, rest 4 min
Sled push	4 × 10m, light sled (~10–15% bodyweight), rest 2 min No sled? 5 × 15m hill sprints or partner-resisted sprints
Backward run	2 × 60m, walk-back rest
Barefoot cooldown walk	One easy lap of the track barefoot, unhurried

The sled push comes after the free sprints, so it doesn't slow them down. If you don't have a sled, the hill sprints guide has the equivalent. Three heavier sessions:

1.Heavy sled pull

6–8 × 20m at about 50% velocity loss, 3 min rest

After the warm-up and two free 20m sprints, pull a sled heavy enough to halve your top speed. Each rep is slow and takes several seconds, so stay patient and keep pushing the ground back. Finish with two free 20m sprints. It is modeled on the heavy-sled studies above, which used sets of 10 × 20m. Start with fewer reps and build.

2.Sled push for team sports

4–6 × 10–15m at 25–50% velocity loss, 2–3 min rest

Hands high on the poles, arms straight, a long lean, and full extension of the back leg on every step. In the high school study above, the heaviest push group gained the most, and the biggest gains came over the first 5m.

3.Heavy pull as a primer

2 × 15m, full recovery, before the main sprints

A couple of heavy pulls in the warm-up force a deep acceleration angle before your free sprints. Keep it to two or three reps so the sled doesn't tire you for the main set.

Treat a heavy sled day as a high-intensity day, with at least 48 hours before the next one. The speed training guide shows how to lay out the week.

Sled setup: surface, harness and timing

Test and train on the same surface. Friction on turf, grass, rubber track or a gym floor varies, and so does wet versus dry. Re-test when you change surface.
For pulls, use a waist belt or harness and a line long enough that the sled can't clip your heels. Take up the slack before each rep so the first step doesn't jerk.
For pushes, set your hands high on the poles for a more upright angle and low for a steeper one. Keep your arms straight and your back flat.
Start from a split stance. Mark the start and finish so every rep covers the same distance.
Film or time a rep every session. If you're folding at the waist or shuffling, the load is too heavy for the goal.

Common mistakes

Picking the load by plate weight: The same sled slows two athletes, or one athlete on two surfaces, by different amounts. Set it by velocity loss.
All sled, no free sprints: Sleds help the first 10m. Free sprints at full speed are still the main work.
Sled before sprints: A long sled set tires you for your fastest reps. Run the free sprints first, or limit the sled to two or three primer reps.
Short rest: Sled reps are maximal efforts. Take 2–3 minutes between them, more after heavy pulls.
A heavy push that turns into a walk: If you can't keep a sprint rhythm, you're doing strength work. That's fine in the gym, but don't count it as speed training.