Sports science isn’t sure that conventional resistance training helps endurance performance. It depends on the individual’s weaknesses. If you’re naturally strong but lack aerobic power, you’re probably better off riding and working on strength on the bike with short hard hills and low-cadence/high-gear repeats. If you lack strength in your legs, weights can help improve this weakness. But then you have to convert that strength into cycling-specific power with on-bike training.
There’s another consideration. As we age, it’s increasingly important to maintain muscle volume. Weights are a great way to do that. I suspect that most riders over 45 or 50 should do squats or leg presses routinely just to stave off sarcopenia (loss of lean muscle tissue). Think of it this way — you’re lifting not to improve your riding next spring but rather to ensure that you’re still able to ride in 20 or 30 years.
Relatively low reps (5-10) and heavier weights build strength most effectively, and that’s why you’re in the weight room. But if you don’t have good flexibility and good form in doing leg exercises, you’re better off using high reps and relatively low weight to avoid injury.
Remember that some great riders can leg press only around 400 pounds, while many strength athletes can top 1,000 — but can’t ride a bike very effectively. So it’s safer to use a weight that allows 15-25 reps. Do several sets. These higher reps will force you to use lighter weight, thus reducing the chance of injury. And higher reps are more specific to cycling as well.
Analyze your strengths and weaknesses. I could squat around 500 pounds in my college football days and was leg pressing 700 pounds in my late 50s. Did that strength make me a better rider? Well, it probably didn’t hurt, but following winters when I didn’t do leg presses I rode just as strongly.
My cycling weaknesses occur at other places in the power production chain. So for riders like me, it makes sense to work on lactate threshold, anaerobic power and so on. These things are best improved by riding.
Coach Fred Matheny is an RBR co-founder who has four decades of road cycling and coaching experience. He has written 14 eBooks and eArticles on cycling training, available in RBR’s eBookstore at Coach Fred Matheny, including the classic Complete Book of Road Bike Training, which includes 4 eBooks comprising 250 pages of timeless, detailed advice and training plans. The Complete Book is one of the many perks of an RBR Premium Membership. Click to read Fred’s full bio.