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Not Gaining Weight During Time off the Bike? Here’s Why That’s Not a Good Thing

Every cyclist — even the most dedicated one — has to take some time off the bike now and then. Whether it’s a busy schedule or an injury, sometimes you’ll spend some time out of the saddle. 

If you’re a fairly regular, fit cyclist, you’ll probably expect to start putting on some pounds when you take a break. After all, fewer calories burned usually translates to weight gained, right? Well, you may be pleasantly surprised when that doesn’t happen. In that case, you’ll likely breathe a sigh of relief — maybe you’ll even feel a little less urgency to get back on the bike.

Don’t be fooled, though. That weight stability is probably hiding the real changes going on in your body. If you’re off the bike for more than a few weeks, your fitness level is dropping rapidly, whether you can see it or not. Longtime cycling coach Darryl MacKenzie has experienced it many times over the years, even when his weight doesn’t change. Here’s why not gaining weight when you’re off the bike may not be a good thing. 

The Big Calorie Burn of Cycling

Distance cycling offers a plethora of benefits. One perk, in particular, may be less obvious: it’s a way to burn a ton of calories. 

When pedaling a century, for instance, highly fit cyclists burn 500–600 calories per hour. On a typical 90-minute ride, that may translate to around 750 calories. That’s more than twice what you’d burn on a 30-minute run.

Burning that many calories means cyclists need to consume more of them — and that’s exactly what some riders want. 

“A lot of cyclists will pedal in order to be able to eat more,” explains Coach Darryl. Even though that’s not his primary motive, he does like that he can enjoy more guilt-free decadent meals or desserts now and then. 

Given how many calories the typical cyclist burns on the bike, surely they will start to gain weight rapidly when they suddenly stop burning those calories during a long break from riding, right? Not necessarily.

The Hidden Weight of Muscle

There’s one big reason behind this mystery weight stability: the difference in weight between muscle and fat. Because muscle is more dense than fat, a portion of muscle weighs about 80% as much as the same volume of fat. And when you’re off the bike for a while, you start to lose muscle mass rapidly, even as you gain fat.

Consider the following data, as reported by M.D. and cycling expert Dr. Gabe Mirkin: One study from the University of Copenhagen showed that fit men in their 20s who were unable to work out for two weeks due to an immobilizing knee brace lost between 22% and 34% of their leg muscle strength. That loss of strength is primarily due to shrinking muscle mass, which would largely offset any corresponding increase in fat.

This is a common phenomenon, so much so that Darryl calls it his “Rule of 11.” If you’re off the bike for more than 11 days, you’ll notice a significant decrease in leg strength. If you’re back on the bike in under 11 days, you won’t notice a big change. Darryl has proven this time and again over the years when he’s been off the bike for recovery or extended trips back home from San Diego to Canada. Once he hits that 11-day mark, he knows he’s in for a slog to get back up to his standard performance level. 

This may be especially true for older cyclists. Although you don’t necessarily lose more muscle mass during breaks when you’re older, you have less muscle mass to begin with, and that may make the drop-off more noticeable. 

The Takeaway: Get Back to Pedaling as Soon as You Can!

The moral of the story? Don’t stay off the bike longer than you have to. Don’t let your stable weight lull you into a sense of complacency. Your fitness level is changing rapidly, and the sooner you get back on the bike, the more quickly you’ll recover.  

As Dr. Mirkin explains, many studies show that a full recovery of your leg strength (and corresponding muscle mass) will take three times the amount of time that you were off the bike. If you extend your time off, you’re setting yourself up for more work. 

Beware, though. When you return to cycling, you may experience the opposite effect of this muscle vs. fat density trend. As you rapidly start building muscle and shedding fat, you may gain weight in those first few weeks. 

“If you’re taking off fat and putting on muscle, you could actually get heavier even as your body appears less bulky,” Darryl explains.

It’s nothing to worry about — in fact, it shows that you’re returning to form. So, don’t wait too long to get going again, and don’t stop once you do. You’ll soon be back to pedaling your regular routine.


When you get back on the bike, you may want to know a few ways to quickly boost your strength and endurance. Check out these tips to help you get back up to speed.

Look for more of Coach Darryl’s tips and insights at his website.

Photo by i yunmai on Unsplash