Whenever you suggest weight training to a cyclist, runner, or triathlete, one of the athlete’s first concerns is whether putting on additional muscle mass will hurt their sport-specific performance. Will more muscle make you slower by increasing you total bodyweight, or make you faster by increasing your strength and resilience? There are a few ways to look at the question.
You don’t need to be bigger to be stronger
Hypertrophy (making muscles bigger) is not the same thing as increasing strength (maximum force production). Professional bodybuilders are not nearly as strong as powerlifters, but powerlifters don’t come close to bodybuilders in terms of muscularity. There are a lot of reasons for this, but one of the most important for endurance athletes is the idea that developing strength depends a lot on improving neurological recruitment, whereas the stimuli for hypertrophy have more to do with inducing structural stress to the muscle (getting pumped).
Athletes looking to increase muscle size utilize more total reps and reps-per-set at moderate to heavy resistance (70-85% of 1RM), and they often use multiple exercises to target the same muscles in different ways and from different angles. This increases the structural stress. In contrast, athletes looking to increase raw strength utilize fewer total reps, fewer reps-per-set, heavy resistance (80-90% of 1RM) and a narrower range of multijoint exercises. This lifting style maximizes neuromuscular recruitment so you activate more existing muscle fibers with each contraction.
Even the recovery between sets is different depending on your goal. Bodybuilders and those looking to increase muscle mass take short rest periods (1-2 minutes) between sets, whereas the athletes going for pure strength take longer (3-5 minute) rest periods. This is similar to sprint training for endurance athletes. When cyclists train for sprints or standing starts, you want to take 3-5 minutes between efforts so you are recovered and able to produce maximum power for each effort.
Endurance athletes gain both mass and strength, at first
Bodybuilders are not weak and powerlifters are not small. There’s obviously plenty of crossover between gaining strength and building muscle mass. In the weight lifting world there is a big division between gaining strength and building muscle. It’s a matter of specialization. With the last good example being Franco Colombo in the 1970s, it’s extremely rare for an athlete to simultaneously be an elite champion in powerlifting and bodybuilding.
None of that matters for most endurance athletes because your strength and muscle mass are both so low that almost any strength training you do will result in structural and neurological stress and therefore lead to both increased muscle mass and increased strength.
Why endurance athletes don’t become bodybuilders
That last section is what scares endurance athletes away from resistance training, but it shouldn’t. Yes, you will gain some lean body mass, especially if you have avoided resistance training for a long time. The reason you are unlikely to gain a lot of muscle mass, however, is that substantial hypertrophy requires very specific focus and intention.
Sustained and substantial hypertrophy requires a lot of nutritional support. Bodybuilders and endurance athletes consume a lot of calories, but bodybuilders consume more protein per kilogram of bodyweight than endurance athletes and expend a fraction of the energy endurance athletes utilize for aerobic (cardio) training. To build muscle you need a caloric surplus, but cyclists and triathletes operate a much smaller energy surplus – and sometimes in an energy deficit. Exercising for hypertrophy without adequate nutritional support won’t result in hypertrophy, and endurance athletes who utilize resistance training and eat like endurance athletes rarely provide the nutritional support necessary for significant hypertrophy.
Gaining lean muscle mass is unlikely to make you slower
For elite amateurs and professional endurance athletes there is great aversion to gaining muscle mass, but that aversion is largely irrelevant for most age groupers, masters, and amateurs. For most of us, the small increase in lean muscle mass will be offset by fat loss and a change in body composition. Your total weight is likely to remain relatively constant, but you will gain strength through improved neuromuscular recruitment. And as I’ve talked about in previous posts, resistance training is likely to improve your ability to complete sport-specific training with greater consistency, and increase the range of activities you can use to supplement your sport-specific training when you can’t ride or swim or run.
Above all, it is important to realize that for the majority of amateur athletes, bodyweight is not your limiting factor for success. You have not maximized your potential for improving aerobic fitness yet, so while losing weight will help you get faster by increasing power to weight ratio, you have more potential for getting faster with improved aerobic fitness than you do by losing weight. That’s why gaining a few pounds of lean muscle mass is not necessarily a bad thing, especially if it makes you a more well rounded athlete who can, in turn, be more consistent with high-quality sport-specific aerobic training.
The bottom line
Resistance training is good for you, especially if you are a middle-aged endurance athlete who is not pursuing a paycheck from endurance sports. You may gain a few pounds, you may stay at the same weight and improve body composition (more muscle, less fat), or you may even lose weight. In any scenario you will gain strength and in the end you will be a better, more well-rounded athlete.
CEO/Head Coach of CTS