Strength Training for Distance Runners and Cyclists: A Look at a New Review

A recent review from Ronnestad and Mujika has evaluated the effects of strength training programs on performance and the components of performance in runners and cyclists.

An abstract can be found here.

As I found with my literature review for hill sprint training (here and here) this review notes that strength training, either heavy-weight and slow or light-weight and explosive, improves running economy. Interestingly, this review states that it may also improve cycling economy, especially as an athlete becomes fatigued.

Ronnestad and Mujika also evaluated the effects of strength training on VO2max, lactate threshold/anaerobic capacity, and performance measures.

I have written on concurrent strength and endurance training in the past, questioning what effect(s) endurance training might have on strength for the strength and power athlete. While this review is concerned with concurrent training, it is strength training for the endurance athlete - and it appears that there is no detriment to endurance performance when strength training is done properly in conjunction with endurance training. I am not sure the opposite is true; based on the evidence we have now, I certainly still believe endurance training may inhibit strength gains for the pure strength and power athlete. Still, I do not believe the most effective timing of concurrent training has been established (same day vs. alternate day, same session vs. separate sessions, etc.).

To help summarize the findings of the review, here are some excerpts:

"... there are no reports of a negative effect of heavy strength and explosive strength training on either cycling or running economy."

"... running economy can be improved by 2–3 strength training sessions per week, it seems a threshold of (explosive) strength training volume and frequency has to be overcome to achieve improved running economy."

" ...none of the studies on long-distance runners and cyclists report a negative effect of strength training on velocity or power output at the lactate threshold."

"... anaerobic running power can increase substantially after a period of added explosive strength training."

"... there are no reports of negative impacts of concurrent training on endurance performance."

"Strength training contributes to enhance endurance performance by improving the economy of movement, delaying fatigue, improving anaerobic capacity, and enhancing maximal speed."

The most interesting section of the review to me was "Potential Mechanisms." Here, the authors give the following mechanisms as an element for improved performance. They were:

1. Altering muscle fiber recruitment pattern  - postponing fatigue in type I fibers, placing less reliance on the less efficient type II fibers,  improving economy, putting less reliance on limited muscle glycogen, improving sprint performance following endurance activity

2. Conversion of type IIx to type IIa - by recruiting the fastest twitching fibers again and again, they could become more oxidative and fatigue resistant

3. Increasing maximal force/rate of force development - increasing muscle-tendon stiffness, improving running economy, lowering relative exercise intensity - reducing the amount of muscle mass activated to generate submaximal power.

The authors go on to provide "potential negative outcomes." The primary negative outcome is hypertrophy - which would mean weight gain. There is a reason why the best middle and long distance runners are not 100 kg. Hypertrophy could also decrease capillary to muscle area ratio - potentially limiting O2 delivery to the muscle. Despite these recognized potential negative consequences, the authors note that when strength training is done in conjunction with large volumes of endurance training, hypertrophy is inhibited (remember this?).

Overall, this study is another piece of evidence to indicate that strength training for the endurance athlete is an effective mode of improving endurance performance. Table 1, adapted from Ronnestad & Mujika, summarizes the effects of strength training on endurance performance:

Table 1.
Benefits	Possible Negative Outcomes
Improved Economy	Increased Body Mass – Lacking evidence
Anaerobic Capacity	Decreased VO2max – No evidence
Lactate Threshold	Increased diffusion distance – No evidence
Delayed Fatigue	Reduced capillarization – No evidence
Maximal Strength	Reduced Oxidative enzyme activity – No evidence
RFD
Maximal velocity
Endurance Performance

 In my next post, I'll provide sample programs for the distance runner, the cyclist and the multisport athlete.

Ronnestad, B. R., & Mujika, I. (2013). Optimizing strength training for running and cycling endurance performance: A review. Scand J Med Sci Sports.