Le rôle du renforcement musculaire chez les runners

Strength training for runners

Perhaps the idea of integrating strength training into your training program strikes you as strange. This is likely due to the fact that strength training has long been considered as being detrimental to endurance and the runner’s performance, with claims that it reduces the mitochondrial content of muscles and the density of capillary vessels.

However, scientists (Jun et al., 2003) have shown that for runners, the main benefit of strength training is improved running economy.

Running economy corresponds to consumption of oxygen per unit of distance. Think of it much in the same way as a car’s fuel economy, in that a runner who can improve their running economy will use less energy to run a given distance.

In this context, Running Care has deciphered for your convenience all the physiological explanations as well as instructions for implementing strength training for runners.

The effects of a strength training program on running endurance

The principal performance parameters for running are:

  • The VO2max (the maximal oxygen consumption)
  • Running economy (consumption of oxygen per unit of distance)

For runners, a strength training regimen has not been shown to lead to a significant increase in maximal oxygen consumption. However, several studies have indicated an improvement in running economy after completing 6 to 14 weeks of strength training using plyometrics and weight training.


The principle of a plyometric exercise is a cycle of muscular stretching and shortening. The muscle contracts: at first in an eccentric (stretching) manner, and then works in a concentric manner (shortening).

A depth landing followed by a vertical jump is an example of a plyometric exercise: the athlete cushions their landing (eccentric phase) then extends their legs (concentric phase).

Plyometric training helps increase your ability to produce a stronger movement over a very short period.

The plyometric contraction is the most common athletic movement as well as the most natural.

The advantages of plyometry:

  • Acts on nervous factors
  • Strength developed beyond concentric maximum
  • Promotes muscular elasticity

Strength and weight training

Strength training regimens which have shown effectiveness with weights require 2 to 3 strength training sessions per week. The use of weight training in association with plyometry has shown a benefit for running economy.

While studies have not shown any increase in lactic acid threshold, some studies have shown an increase in speed reaching lactic threshold after strength training. The strength training method used (weight training or plyometry) does not matter much. This improvement in the threshold could be related to an improvement in running economy. Furthermore, no study has shown a reduction in threshold after the addition of strength training to endurance training.

The effects of strength training on a runner’s performance

Whether it’s plyometric training or training with weights near your maximum, the link between strength training and endurance training can improve your endurance. Unfortunately, the studies only analyzed performance over short exertions (5 km, 3 km, and maximum effort time at MAS). Of course, the link between “improving MAS and improving energy economy” leads one to believe there will equally be performance increases over longer exertions.

What are the mechanisms that could explain the benefits of weight training?

Above all, note that for runners, maximal strength training and plyometry are both beneficial. The specificity of running’s eccentric nature means that with each stride the muscles of the lower limbs will perform a muscular contraction all while lengthening in order to absorb the body’s weight. This eccentric contraction is much more traumatizing to the muscle than a concentric contraction (shortening) or isometric (static). This is one of the causes of stiffness after running sessions.

Strength training can reinforce the rigidity of the musculotendinous system resulting in an improvement in running economy by learning to more effectively use the elastic energy stored in each stride.

Strength training lets the type I (slow twitch) muscle fibers adapt and/or increases the percentage of type IIA (intermediate fast twitch) fibers at the cost of type IIB (extremely fast twitch) fibers. Strength training can also help improve neuromuscular stimulation.

Can strength training have negative effects on performance?

Weight gain is the risk most often brought up by runners. However, all the studies agree that there was no evidence of weight gain after adding strength training to an endurance training regimen.

No reduction of VO2max and no reduction of lactic threshold were observed.

If the classic endurance training sessions are maintained, strength training has not been observed to have any negative side effects.

How can strength training be integrated into endurance training?

If you want to improve your running performance, we suggest you replace part of your endurance training with strength training sessions. This is only recommended if you train at least three times a week. If you engage in fewer than three sessions per week, it would be best to only run and add a few plyometry exercises during one or two sessions during the week.

Winter is the ideal period for your strength training sessions. The integration should be done gradually. You can take advantage of the poor weather to do your sessions in the comfort of your home.

Ideally, the program will include two or three strength training sessions per week over a minimum period of six weeks. After this strength development phase and as the competitions start approaching, you can switch to training that is more and more specific without giving up on strength training, maintaining one session per week.

You can choose to go with weight training or plyometry. The advantage of plyometry is that it requires very little equipment, making it accessible for everyone. Plyometry uses functional, near-realistic movements that work numerous muscles with each movement without isolating them from each other. The program aims to work out the quadriceps, hamstrings, and the triceps surae.

Both methods should start with two to three weeks of learning the technical movements and gradual weight increase.

This implementation is followed by the real strength training regimen, which will mean 2 to 3 sessions per week in addition to endurance training.

Example of a weight lifting routine

  • 3 to 5 sets of 3 to 5 repetitions with 90% of maximum weight, 1 maximum repetition (1 RM)
  • 3 sets of 6 repetitions of 85% of maximum weight
  • 4 sets of 4 maximum repetitions
  • 2 to 3 minutes of recovery between each set

Example of a plyometry routine

Plyometry consists of following an eccentric contraction with a concentric contraction in as little time as possible. To do this, you can jump from a higher level (e.g. a 50 cm tall plyo-box) followed by a vertical jump, jumping on one leg, hurdle jumps (different heights), squat jumps, etc.

It is also possible to add weights during the jumps.

The protocol to follow goes from 30 to 200 jumps per session with 5 to 20 repetitions per set.

Replacing certain endurance sessions with strength training sessions or also adding muscular reinforcement sessions will not only let you improve your performance in endurance challenges or ultras, but also help you to stave off injuries by reinforcing your weakest areas.

Consult your Running Care app to learn more about our injury prevention programs. You can then benefit from global muscular reinforcement sessions, as well as specific sessions depending on your areas of weakness and level of experience.

Written by:
Guillaume Boitel – Doctor in Physiology, Bio-mechanics & Sports Sciences


Rønnestad BR, Mujika I. Optimizing strength training for running and cycling endurance performance: A review. Scand J Med Sci Sports. 2013 Aug 5. 


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