Some research suggests that you can start to lose muscle in as quickly as one week of inactivity - as much as 2 pounds if you are fully immobilized (3). And another study suggests your muscle size can decrease by about 11% after ten days without exercise, even when you aren't bed ridden (4).
“However, following long periods of extensive exercise, the body's metabolic system may be stressed to its limit, therefore it is advised for anywhere from a minimum of 3-7 days of complete rest, hydration and sleep.
Some athletes see a loss of about 6% muscle density after three weeks. Some power lifters see losses of as much as 35% after seven months. Young women who trained for seven weeks and gained two pounds of muscle mass, lost nearly all of it after detraining for seven weeks.
According to the research of pro bodybuilder Jeff Nippard, the timeframe to get your muscle gains back is typically around half the time you took off. So, if you had a 2-month break from lifting, it might take just a month to get all of your gains back. Took six months off? You'll need three months to gain it all back.
How long does it take muscles to atrophy? The amount of time it takes for your muscles to atrophy depends on your age, fitness level and cause of atrophy. If your muscle atrophy is due to disuse (physiologic), the process can start within two to three weeks of not using your muscles.
It's recommended to rest for 72 hours before working out the same muscle group again. This gives your body the time it needs for muscle recovery and growth without risking injury from overtraining or under-recovery.
It turns out, exercise experts pretty much agree on the number of rest days people who are in good shape and exercising regularly should take: On average, you should be taking two days per week for rest and active recovery.
Taking a few days off will actually do more to improve your fitness and training. Typically, I recommend that people take a few days off from exercising every six to eight weeks, assuming you work out at a good intensity and are consistent.
Contrary to what you may have heard, you won't lose muscle or strength if you take a week or two off from the gym. It takes a while to build muscle, and it doesn't just disappear the second you stop lifting. Take more than three weeks off, though, and you will probably lose some strength and muscle.
"Working out when sore is okay as long as it isn't affecting your movement to the point where it's causing you to compensate and do something in a way that's unsafe," says Dr. Hedt. "Muscle soreness can be a deterrent to exercising, but it's temporary and the more you exercise, the less you should feel it.
Do Rest Days Help Your Muscles Grow? The short and sweet answer is YES, muscles do grow during the rest periods between workout sessions. Not taking rest days hinders the process of protein synthesis, which, in turn, slows down your muscle growth.
It's recommended to take a rest day every three to five days. If you do vigorous cardio, you'll want to take more frequent rest days. You can also have an active rest day by doing a light workout, like gentle stretching.
With that being said, different muscle groups tend to have different rates of recovery, with smaller muscles—biceps, triceps, calves—being able to recover more quickly than larger muscles—lats, quads, hamstrings, etc. In addition, different individuals are able to handle different amounts of training volume.
This minimal amount of excess weight can make you feel heavier, and your muscles may not respond as well as they normally do because they've had an extra day off, but weight gain in the form of excess fat is still unlikely.
Skipping your workout becomes a problem when you skip for more than two days in a row, say experts. It's incredibly easy for one missed workout to turn into two, three and more. It's okay to miss one or two workouts but the key is never to skip more than two days in a row.
To get optimal gains in maximum strength, the body needs a complete recovery, so 48 to 72 hours. In concrete terms, if you perform a chest session, you will need to wait between 2 to 3 days before working the same muscle group again.
Your rest day nutrition should include plenty of protein from a variety of sources, complex carbohydrates to fuel recovery, and healthy fats to help bring down inflammation created by training. Aim for 20-30g protein every 2-4 hours throughout the day.
Are you still getting results? The answer is YES. Just because you don't feel muscle soreness as intensely as when you first began doesn't mean a workout is not benefiting you. Your body is an amazing machine and it adapts very rapidly to whatever challenges you present it with.
If they want weight loss along with muscle growth, reducing calories on rest days can help. The body does still needs nutrients to aid in recovery. As long as these needs are met, calories can be lowered slightly.
Their guidelines recommend 150 minutes of moderate-intensity aerobic physical activity each week or vigorous-intensity aerobic activity for a minimum of 20 minutes three days a week. Additionally, you should do strength training twice a week.
Rest days are an important part of exercise for all levels of fitness. A person should take a rest day every 7–10 days or as needed to help the body and mind recover. A rest day can be an active day that incorporates gentle exercises such as walking or yoga. Alternatively, a person may opt for a full day of relaxation.
Those who need to lose weight might need even more. Based on that, working out 2 hours per day might not be a very big stretch for most people. However, if you are new to exercise, a 2 hour workout can do more harm than good. Start with 15 minute sessions, then gradually at time as your body adapts.
Three hours of exercise is too much for the average person. It's more likely to lead to burnout than sustained weight loss.