Endurance athletes and coaches are typically cautious when it comes to including strength training into their programmes. Their apprehension is largely based on concerns of increased lean body mass or the reduced quality of subsequent on the bike training sessions. Earlier, poorly designed studies on concurrent (endurance and strength) training showed no improvements in endurance performance following the addition of strength training to already high training loads. However, recent research shows that including strength training may be of benefit for endurance athletes. Studies conducted on runners, cyclists and triathletes have all shown positive additive effects of strength training on endurance performance.
Success in endurance sport requires athletes to sustain the highest possible speed or power output at the lowest energy cost. In certain situations, athletes will be required to accelerate to break away from the pack or sprint to the line to take the win. In these situations, glycolytic capacity and maximal speed become important determinants of success. In a previous article, we mentioned the four main physiological determinants of endurance performance;
- Cycling economy
- Threshold intensity
- Muscular power
A recent review on optimising strength training for running and cycling performance, concluded that, despite resulting in improvements in exercise economy and time trial performance, strength training was not an appropriate method for increasing VO2max in trained endurance athletes. While it is not disputed that high VO2max values are associated with endurance capacity, the highest VO2max value does not always result in the best endurance performance and there can be large differences in performance between athletes with similar VO2max values. Therefore, improvements in endurance performance following strength training, are most likely the result of changes in other variables.
We define cycling economy as the metabolic or energetic cost of maintaining a certain speed or power output. A good exercise economy is crucial for success in endurance sport and there can be large differences between individuals’ economy, despite similar VO2max values. The addition of strength training to an endurance athlete’s training programme, may result in greater improvements in exercise economy when compared to endurance training alone. Cyclists and triathletes are reported to show improvements in economy following maximal strength training. Maximal strength training refers to high load, low velocity movements (1 – 15 RM), where the goal is to increase the maximal force generating capacity of the muscles. Typical exercises in a maximal strength programme would be squats and deadlifts. The current literature supports the use of maximal strength training for improving economy.
A cyclist’s threshold refers to the highest intensity that can be sustained for a prolonged period of time (40 – 60 minutes). One of the main goals of endurance training is to increase the intensity at threshold, allowing the athlete to sustain a higher power output for a longer period of time. A recent study on young male cyclists showed the addition of strength training resulted in an 8% improvement in 45 minute time trial performance compared to endurance training alone.
Peak power output
Peak power output (PPO) is able to differentiate endurance performance between cyclists. VO2max and economy will both influence PPO, but glycolytic capacity and neuromuscular factors will also play a role. Maximal strength training, prescribed in combination with endurance training has been shown to improve PPO.
Endurance athletes may also be required to produce a high power output at the start of mass-start events (XCO), to close a gap, break away or sprint to the line. Maximal strength training in cyclists has both been shown to increase the force producing capacity of the muscles.
How does strength training improve endurance performance?
One of the proposed mechanisms for improved endurance performance following strength training is increases in the maximum strength of the type I fibres. Type I muscle fibres are more fatigue resistant than type II fibres and increasing the strength of type I fibres may increase their time to fatigue and thus delay the recruitment of the less economical type II fibres. In addition, type II muscles fibres may change their characteristics from type IIX to the more fatigue resistant and powerful type IIA fibres.
Endurance athletes can improve their performance by the correct application of strength training. Strength training has been shown to improve a variety of factors associated with endurance performance in novice to well-trained endurance athletes. Strength training sessions should be tailored to the athlete’s needs based on their experience and current strength level. Strength training should be viewed by endurance athletes as an additional tool in their goal to improve performance.