It may surprise you, but pushing through a workout when you’re sore might do more harm than good. Rest days can have almost as big of an impact on your fitness goals as your time in the gym. Well + Good interviewed experts to find out the best practices when it comes to recovering.
What makes you stronger? When you work out, you create “micro tears” in your muscles that heal themselves, strengthening your muscles. By skipping rest, you don’t give your muscles enough time to rebuild. This can cause issues. “In the scenario where the muscle does not have time to recover, a catabolic process occurs where the muscles degrade and continually break down,” says Austin Martinez, MS, CSCS, ATC, director of education for StretchLab. “This process is referred to as ‘overtraining.’ When this happens, your cortisol levels become elevated, which causes stress, adrenal fatigue, and muscle breakdown.”
Along with the tears, you also go through a chemical process during your work out. This too needs time to reset. “You’re depleting the glycogen, which is the energy inside of the muscle, and in order to replenish the glycogen to perform at that level again you must give your muscle the time it needs to do so,” says regenerative sports medicine doctor Rand McClain, MD. “The build-up of certain types of acid within the muscle cell can result in failure of the muscle cell to perform but also cause some chemical (acid) damage that needs time to repair.” So before you hit the gym again, you’ll want to give all of these things ample time to reset.
There’s no easy answer for this, as everyone is different. Variables like age, fitness level, sleep, nutrition, and stress can affect it. “The time it takes for a muscle to recover is dependent upon the intensity and the load placed upon the muscle—and it includes both the amount of energy required in a burst, as well as the total amount of energy required in the entire workout,” says Dr. McClain. “Using bigger muscles can take a bigger toll on the entire body and may require more rest between bouts of exercise.”
A good rule of thumb is to take 24 hours of rest between high-intensity workouts like weight training. For lower impact workouts, you can usually work out a couple of days in a row. “Overall, ‘load’—which includes the overall output generally quantified by the number of calories expended—also determines the amount of rest needed between exercise bouts,” says Dr. McClain, adding that this can differ based on your fitness levels.
Rest isn’t just needed after a workout—it can also be healthy during one. Martinez explains that during a work out like HIIT training, different rest times have different outcomes. For example, if you’re goal is to grow your muscles, 30 to 90 seconds between sets allows for more ATP energy regeneration. If increased endurance is your hope, rest for less than 20 seconds. Lastly, 3-minute rests are effective for building strength.
Typically, second-day soreness is a good indicator that you should take a rest day but isn’t always the case. Exceptions could be if you’re just starting out or training for something intense. “Some level of soreness often has to be ‘worked though,’ and, in fact, the concept of active recovery is one that uses low level exercise to speed the recovery from prior bouts of higher intensity and greater load workouts,” says Dr. McClain.
A good way to tell if you should work out is by answering these four questions: “Am I emotionally ready for this workout” “Is anything swelling up?” “Do I have motion in all of my joints?” “Are certain body parts compensating for others?” If you answered yes to any of them, it’s probably safer to take some recovery time.
“The concept of ‘No Pain, No Gain’ has long ago been replaced by ‘No Brain, No Gain,’” says Dr. McClain. “The idea before was that if you trained to the point of muscle soreness, you were certain to have trained hard enough to stimulate an improvement in muscle fitness. However, we know now that in order to stimulate improved muscle fitness, one does not have to reach the point of muscle soreness.”
Remember, recovery time doesn’t mean you have to be inactive. “Stretching is typically a good idea if there is no muscle injury or excessive inflammation, and foam rolling, percussion, hot and cold therapies each have their place in muscle recovery,” says Martinez. “But nutrition and rest—aka doing absolutely nothing—both hold essential places in recovery too.”
“Adding stretching and foam rolling into your post-workout regimen can be very helpful in preventing muscle soreness, injury, and improving your performance during your workouts,” says Martinez. He suggests targeting the areas that you’ve worked—so, for example, on leg day you should be stretching your hamstrings, quadriceps, glutes, and calves—for best results.