Engeroff’s plyometric program involved nothing but hopping on the spot

Friday, May 26th, 2023

Plyometric training can make you a more efficient runner, Alex Hutchinson notes, but there’s still plenty of debate about how it works:

As a result, studies like this one in Sports Biomechanics, published last month by a group led by Aurélien Patoz of the University of Lausanne, don’t garner much attention. They found a 3.9 percent improvement in running economy after eight weeks of either plyometric or dynamic strength training, roughly comparable to what Nike’s original Vaporfly 4% shoe produced. (They also found no evidence that either form of training altered running stride in any significant way, for what it’s worth.)

Why no excitement about a free four-percent boost? As someone who has experimented on and off with various forms of plyometric training over several decades, let me venture a hypothesis: it’s perceived as too complicated, and possibly risky, for most of us.

Does it need to be that complicated?

That’s the question tackled by another recent study, this one led by Tobias Engeroff of Goethe University Frankfurt and published in Scientific Reports. They stripped plyometric training down to its bare bones, tested it on a group of amateur runners—and still found a significant improvement in running economy after just six weeks. The exact size of the improvement depends on how you measure it and at what speed, but was between 2 and 4 percent.

Engeroff’s plyometric program involved nothing but hopping on the spot. Specifically, “participants were instructed to start with both feet no wider than hip width apart and to hop as high as possible with both legs, keeping the knees extended and aiming to minimize ground contact time.” They started by hopping for 10 seconds, resting for 50 seconds, and repeating five times for a total of five minutes. They did this five-minute program daily, decreasing the rest and increasing the number of sets each week: the second week was 6 sets of 10 seconds of hopping with 40 seconds of rest; the sixth and final week was 15 sets of 10 seconds hopping with 10 seconds of rest, still totaling five minutes.

This program was based on the idea that it’s tendon stiffness that boosts running economy. In particular, the stretch and recoil of the Achilles tendon provides between half and three-quarters of the positive work required for running, by some estimates. Engeroff’s short daily program draws on recent research by Keith Baar and others suggesting that connective tissue such as tendons responds best to brief, frequent stimulus rather than longer and harder workouts. Notably, this approach didn’t injure any of the runners.


  1. Pseudo-Chrysostom says:

    Improvements in tendon strength may be a factor, but the number one thing wrt plyometrics is neural drive, conditioning motor engrams to move in more impulsive ways. This is also related to where ‘noob gains’ in novice lifters come from – greater muscle recruitment through higher neural drive in people who theretofore have never made lifting heavy a regular practice – before other factors (like hypertrophy, vascularization, or metabolic efficiency) start becoming primary limiting factors (there is no speed without strength).

    The granddaddy of this area of investigation comes from the wide wild world of soviet sports science (winning medals in international competitions was considered a matter of strategic significance by the politburo, so there was significant investment of human capital). In particular the work of Yuri V. Verkhoshansky, which was reproduced in english in the books ‘Supertraining’ and ‘Special Strength Training’ under the term ‘shock method’.

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