Coach Fred Matheny Replies:
I get asked this frequently. Unfortunately, using a heavy bike to climb probably won’t make you a better climber, even though it makes your light bike feel faster.
Here’s why: You must generate a certain number of watts at a given heart rate to climb a hill (and to get a certain training effect from that effort). It doesn’t matter if you go up the hill slowly on a heavy bike or faster on a light bike. The training effect is the same.
For example, let’s say you can climb a one-mile hill on your heavy bike at an average of 300 watts, a cadence of 80 rpm and a heart rate of 160 bpm. On your light bike, if you average the same watts, cadence and heart rate, you’ll ascend the hill faster but the physiological effects are identical.
There’s one exception: The hill won’t take as long to climb on the light bike, so the work interval is shorter. This can be offset by sprinting over the top for as long as it takes to even out the time.
Some riders argue that although all that may be true from a cardiovascular standpoint, climbing on a heavier bike builds muscular strength just like lifting heavier weights.
Maybe. But I’ve never seen a study that proves it. Here’s my theory:
Let’s assume that a hill takes 3 minutes to climb on a heavy bike and 2:30 on a light one. Because you’re interested in strength development, you pedal at a slow 60 rpm in both cases.
So, on the heavy bike you do 180 reps on the ascent. On the light one, you do 150 reps because it allows you to climb faster.
That’s a lot different from doing sets of, say, 15 arm curls with a 30-pound dumbbell, then switching to a 40-pound dumbbell and doing sets of 5 reps to build strength.
Regardless of whether you’re turning the crank 150 or 180 times, you’re primarily building endurance with high reps, at least in comparison to low-rep weight lifting. So the analogy doesn’t work.
I suppose that if you rode a bike that weighs 100 pounds uphill at 30 rpm, you might experience strength development.
You might also experience your kneecaps shooting out the front of your tights like watermelon seeds squeezed between your fingers.
Bottom line: If you want to improve leg strength, do squats or leg presses. Then convert that weight-room strength to cycling-specific power with intervals, climbing and training time trials.
After saying all that, I admit that I train in winter on a heavy bike. The main reason is practical. My beater with fenders and wide tires is better for slushy and gritty roads. But I do like how my good bike feels light and sprightly after riding the heavy one for several months.
The benefit seems psychological rather than physiological, but that’s not bad.
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.