Only 11 of 19 lifters jumped higher after a heavy squat
In short
Nineteen collegiate basketball players squatted at 80% 1RM to velocity-loss thresholds of 5%, 10% and 20%, then jumped at 3 and 8 minutes post-squat. There were no significant group-level improvements in jump height, peak power output or reactive strength index under any condition (all P>0.05). At the individual level the 20% velocity-loss condition produced the most responders, 11 of 19 (58%). Relative strength did not predict who responded.
Jump higher after a heavy squat — post-activation performance enhancement, or PAPE. This study tested it across three conditions set by velocity loss, and the answer split between the group average and the individuals inside it.
Nineteen collegiate basketball players completed three familiarisation sessions, then all four conditions in a randomised crossover: control (passive rest), and 80% 1RM squats terminated at 5%, 10% and 20% velocity loss. Countermovement jump height, peak power output and modified reactive strength index were measured at 3 and 8 minutes after the squat.
At group level, nothing
Linear mixed-effects models found no significant condition × time interactions and no main effects of condition for jump height, peak power output or reactive strength index (all P>0.05). Whether the set stopped at 5% or 20%, nothing separated it from passive rest at group level.
The authors' interpretation is the practically useful part: a comprehensive warm-up may itself create a performance ceiling. If the body is already primed, stacking one more heavy squat on top leaves nothing further to raise.
Individually, a bit over half responded
The researchers calculated the smallest worthwhile change to identify individual responders. The condition producing the most was 20% velocity loss, at 11 of 19 players (58%).
Repetition counts complete the picture. The 5% and 10% conditions did not differ from each other, but both were significantly lower than the 20% condition (P<0.01). The condition that produced the most responders is also the one where the most work got done.
Stronger lifters did not respond better
PAPE is commonly said to show up more in people with higher relative strength. This study entered mean-centred relative strength into the model and found no significant strength × time × condition interaction. Who responded was not explained by how strong they were.
Nineteen athletes, crossover design, one sport. The authors' conclusion is explicit — squat protocols at 5–20% velocity loss and 80% 1RM produced no group-level jump improvement, and inter-individual variability was high enough that PAPE has to be programmed individually. Rest intervals in contrast training are covered in 30-second rest in contrast training, and velocity loss as a training cutoff in velocity loss 10% vs 20%.
So are you a responder?
The study leaves one practical instruction: do not decide from the average, measure it. Use the study's own method — warm up, take several jumps to establish a baseline, do the heavy squat, then jump again at 3 and 8 minutes, and repeat that across several separate days. If it rises every time, you respond. If the direction wobbles, that is measurement noise.
The link to a strength score is a negative one, which makes it clearer. Since relative strength did not predict response, "my score is high so I am probably a responder" has no support in this data. A Muscle Index score comes from Big 3 1RMs, and that number says nothing about how much your jump will rise five minutes later. Track and judge the two separately.
Frequently asked questions
Does a heavy squat make you jump higher?
Not at group level in this study. With 19 collegiate basketball players squatting at 80% 1RM to 5%, 10% and 20% velocity loss and jumping at 3 and 8 minutes after, there were no significant condition effects on jump height, peak power output or reactive strength index (P>0.05).
How many people actually respond?
Applying a smallest-worthwhile-change threshold to individuals, the best condition was 20% velocity loss, where 11 of 19 players responded — 58%. The other conditions produced fewer.
Why was there no effect on average?
The authors suggest a comprehensive warm-up may already create a performance ceiling. If the body is primed, adding a heavy squat leaves no further headroom to exploit.
Do stronger lifters respond better?
Not here. Mean-centred relative strength was entered into the model and the strength × time × condition interaction was not significant, so response was not explained by how strong the athlete was.
How do you find out whether you respond?
By testing it. Warm up, take several jumps for a baseline, do the heavy squat, then jump again at 3 and 8 minutes, and repeat across several separate days. Consistent improvement means you respond; a direction that wobbles is measurement variation.
Source: PubMed