7 Reasons Why You Might Gain Weight When You’re Trying to Lose It

1. You’re overcompensating.

This is easy to do when you start ramping up your routine. You think, “I ran 16 kilometres; I can eat what I want,” which turns into way more than you need. You don’t need to count every calorie, but loosely tracking what you’re burning off and what you’re taking in around your runs can help you avoid overcompensating. Jot down your prerun snack, keep a tally of your midrun fuel, and note what you toss down the hatch when you’re done. That number shouldn’t exceed what your GPS says you’ve burned. Then eat as you normally would the rest of the day.

2. You’re swole.

Like, really. You’re a bit swollen from the micro trauma of working out, especially if you’ve just gotten started or have recently ramped it up. Hard runs and/or heavy lifting sessions in the gym put stress on your muscle fibres, causing micro traumas 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.

3. Your muscles are hoarding fuel.

It’s not uncommon to gain a few kilos when you start ramping up your runs, like when you’re training for your first marathon. 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 one or two kilos.

As you get more fit, you’ll need less stored glycogen to do the same amount of work. 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 run and in the gym by getting bigger and stronger. And here’s an often overlooked fact: Muscle tissue is more dense than fat tissue. So as you gain more muscle and lose fat, you change your overall body composition, which can result in a higher weight, but a smaller figure and better health.

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

5. You HIIT too often.

Though high-intensity interval training can be very effective at improving fitness and shedding kilos, 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. Or you can invest in a heart rate variability (HRV) strap, which tracks your morning heart rate variability—the change in time between successive beats. Higher 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—eat less to lose weight, right?—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. Of course that doesn’t mean you should throw all moderation out the window. Eating to excess, particularly eating nutritionally-barren processed foods, is never a good idea. But 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.