The Claim

Even though the players got stronger, their ability to jump higher or more powerfully didn’t improve after five weeks of leg press training — meaning strength on the machine doesn’t automatically make you jump better.

Source: The Effect of Unilateral and Bilateral Leg Press Training on Lower Body Strength and Power and Athletic Performance in Adolescent Rugby Players

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
54score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Even though the players got stronger, their ability to jump higher or more powerfully didn’t improve after five weeks of leg press training — meaning strength on the machine doesn’t automatically make you jump better.

See the scientific wording

Five weeks of unilateral or bilateral leg press training does not improve vertical jump height or peak power in adolescent male rugby players, as no significant changes were observed in countermovement jump performance despite increases in lower body strength, indicating a lack of transfer from machine-based strength training to explosive power in this context.

What the research says

1 study
  1. Study: The Effect of Unilateral and Bilateral Leg Press Training on Lower Body Strength and Power and Athletic Performance in Adolescent Rugby Players

    Even though the players got stronger from doing leg presses, they didn’t jump any higher—showing that getting stronger on machines doesn’t always make you more explosive in sports.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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