7 Reasons You May Be Gaining Weight If You’re Exercising More (2024)

It can feel super frustrating to step on a scale after months of training and focusing on a healthy diet only to find the number is higher than when you starting riding more and watching what you eat. It often leaves you wondering, why am I gaining weight? And what can I do to stop it?

For starters, you don’t need to halt your cycling routine. And you probably want to pay attention to other things you’ve been gaining, like boosted energy, elevated mood, sounder sleep, and the list goes on! Second, take a breath and read the advice we have from experts who explain why you might gain when you start working out.

It’s important to know that weight loss is a reasonable goal as long as you approach it in a healthy manner. But exercise and nutrition aren’t just a numbers game, explains California-based, NASM-certified master trainer Josh Elsesser.

“Your workout routine and how you fuel yourself impacts your metabolism, fuel storage, and key hormones like cortisol, insulin, thyroid, and sex hormones, which are all critical for success when you’re trying to hit your optimum weight,” he says.

If you’ve been wondering why you might be gaining weight, here are seven reasons why, plus what to do about it.

1. You‘re overcompensating

Unfortunately, exercise doesn’t burn what we often think it will. You don’t need to count every calorie—and certainly shouldn’t if you notice disordered eating habits from doing so—but loosely tracking what you’re burning off and what you’re taking in around your rides can help you avoid overcompensating. Use your wearable—or even better, a power meter if you have one—for the most accurate number.

It’s not only about numbers, as we we explain more below, but at least looking generally at your energy intake and burn can give you some insight.

2. You’re swole

We all become a bit swollen from the micro trauma of working out, especially if you’ve just started or have recently ramped it up. Hard rides and heavy lifting sessions put stress on your muscle fibers, causing micro tears that lead to inflammation, a necessary part of the healing and repair process. Your body responds by retaining fluid. It’s not permanent, but it can be persistent until you adjust to your new routine.

Be sure to respect your rest days so you can fully recover and come back stronger. And give yourself time to adjust.

3. Your muscles are hoarding fuel

If you’re training for your first multi-day charity ride or a century, your muscles respond to the elevated effort level by storing more glycogen, which binds with water in your muscle cells to keep you fueled and can tick the scale up by two or three pounds.

As you get more fit, you’ll need less stored glycogen to do the same amount of work, i.e. your body will work more efficiently. It’s easier said than done, but stay patient and focus on the long-term goal instead of fixating on what the scale says today.

4. You’ve gained muscle

Your muscles respond to the stress of hard training on the bike and in the gym by getting bigger and stronger. Here’s an often overlooked fact: Muscle tissue is more dense than fat tissue. As you gain more muscle and lose fat, you change your overall body composition, which can result in a higher weight, but a smaller size and better health.

If the scale has inched up, but your waistline hasn’t and you feel strong overall, don’t sweat the pounds; they’re increasing your power.

5. You HIIT too often

Though high-intensity interval training can be very effective at improving fitness and shedding pounds, too much can put too much stress on your system and lead to the opposite result.

“People forget that exercise is stress,” Elsesser says. “It’s generally positive stress, but when you put an excessive physical stress like high-intensity exercise on top of an already stressed system, your body will view it as negative, and you’ll increase cortisol production. When cortisol is high, it can lead to insulin resistance, lower levels of thyroid stimulating hormones, and depression of testosterone production in men and progesterone production in women,” he says.

When left unchecked, Elsesser says it makes it very difficult to lose weight. To keep things in control, limit the eye-popping efforts to about 20 percent of your total training volume. For example, if you’re training five days a week, that’s just one HIIT day per week.

6. You’re not recovering properly

Training is a process in which you push your body harder than usual, then pull back and let it recover. This allows you to bounce back even stronger and more resilient, and you can repeat that process to perform at your best. Too many people push the first part of the process (the hard training) while shortchanging the second part (the pulling back and recovering). That can leave you with chronic inflammation and hormonal disruption, both of which can lead to stifled weight loss or even weight gain.

The good news is that there are tools available now that can help keep your recovery on track. Many Garmin products offer recovery time based off of your heart rate training to let you know how long you should recover before you’re ready for your next workout. Other wearables, like Whoop and Oura, focus on heart rate variability (and other factors like sleep) to let you know when you’re overdoing it and should take a break.

Higher heart rate variability is a sign that all systems are recovered and ready to go; lower means you’re under-recovered. “I like heart rate variability because it’s an indication of how you’re responding and recovering to all your stress on a daily basis,” Elsesser says.

7. You’re not eating enough

It sounds counterintuitive, but that’s not quite how it works. “You can either exercise more and eat more, or exercise less and eat less, but you can’t exercise more and eat less. It just doesn’t work,” Elsesser says.

You need to match increased training with properly increased fueling so you can recover and make progress—including weight loss.

When you skimp on fuel, you not only never fully recover, but your body also goes into low-power mode (much like your phone when the battery is running low), so your metabolism dips, and workouts suffer. Fuel yourself and satisfy your hunger with whole foods including lean proteins, complex carbohydrates, healthy fats, and plenty of fruits and vegetables throughout the day.