When it comes to classes or work, we recognize that a few days off can be recharging and renewing. When working out this can be harder to see; while we may think more exercise equals better results, science says this isn’t the case. Here’s why rest days are so important to see the gains you’re working toward.

Person lies on gym floor, exhausted after lifting weightsGrowth days

First, we need to change our thinking: Days away from the gym might be known as rest days, but really, they’re growth days. Downtime between workouts (whether you’re lifting, doing cardio or training for a sport) is when our bodies have a chance to actually build muscle.

Strenuous workouts cause muscle breakdown, while rest allows our bodies to build it back up. If there are no growth days in your routine, continuous muscle breakdown may hinder your progress.

Growth days also are the time when our bodies replenish glycogen levels. Glycogen is the molecule that fuels activity. As we exercise, our glycogen gets depleted. When we don’t give our bodies enough time and nutritious food between workouts to replenish this fuel source, we start feeling fatigued and tend to underperform.

Fewer growth days equals less energy and less gains.

Recovery zone

Growth days are also vital to our mental health. When it comes to training, a good workout can boost endorphins, the “happy hormone,” and help us feel calmer in the moment. However, overtraining can lead to irritability, sleeplessness, diminished performance and decreased appetite, all of which contribute to mental exhaustion and fatigue.

Taking two to three days off from intense exercise each week while engaging in some form of active recovery will allow you to get your blood flowing to help facilitate muscle repair.

If physical activity is already a part of your long-term emotional health strategy, try building in active rest for your growth days—activities like yoga or a brisk walk will give your muscles time to repair and rebuild without overdoing it. Avoid pushing your body too hard on these days and instead focus on low-intensity movements that allow you to channel energy without activating your nervous system.

Prepping for personal records

If you’ve ever trained for a race or a big game, you know you don’t go all-out leading up to it: The Broncos wouldn’t play a full, high-intensity game the night before they were in the Super Bowl, and professional runners don’t do an uphill marathon the night before they compete.

Why is this? Growth days help prepare our bodies for our best performance. They’re the days when we fuel up, get a good night’s sleep, rest, relax, recharge. We set ourselves up for success and don’t expend all our energy or effort leading up to the big moment.

In order to elevate your performance every time you dive into the pool, step into the weight room or hit the track, start thinking of it like your next big event. Build in growth days before you want to hit a personal record or see improvements to allow your body to be in its best shape for that to happen.

For more ways to make your rest days count, schedule a session with a personal trainer at The Rec to review your goals and strategies to achieve them. And be sure to take advantage of the MSK Clinic for a free 30-minute consultation with a physical therapist about any pains or strains you might be feeling.