Injury, stress, sickness, or other reasons may force you to pause your workout regimen. When you take this break, you will almost certainly have to contend with losing muscle mass before you start working out again. So, how long will it take to lose muscle mass? Keep reading to find out.
6 Days (72 Hours)
According to fitness experts, your muscle mass will start to decline if you do not exercise for 72 hours at a stretch. This muscle decline is especially noticeable in the heart. After six days of break from exercise, the heart will start to pump less blood per beat. However, this muscle mass decline becomes noticeable only after three to four weeks of break from your workout regimen.
Note that certain factors influence the rate your muscles decline while taking a break. These factors will be discussed below.
- The Length of Time you have Been Exercising
Individuals who have been exercising for long periods have an advantage when they have to take a break. If you have big and developed muscles, you will retain all of them during your inactive days. 
- Your Age
As you age, it becomes harder for you to maintain muscle mass. The nervous system plays a part in this regard. As people grow older, their motor neurons begin to decline. Scientists say this decline is more rapid at ages 60 – 70. The motor neurons influence muscle relaxation and contraction. So, a decline in motor neurons means a decline in muscle fibers. This means your muscle’s capability to break down and reform bigger threads will be impaired.
You can prevent this alteration to the functioning of the nervous system by doing strength training. However, your muscle mass will decline if you stop your exercise regimen.
- What You Eat
Your muscles are essentially protein. Therefore, you should include sufficient protein in your everyday diet during your workout hiatus. Every day, your body needs amino acids from proteins to build and repair muscle tissues. If you fail to supply your body with enough proteins, it may begin to break down your muscle stores. This will lead to muscle decline.
Protein requirements differ from individual to individual. However, nutrition experts recommend that active individuals consume between 1.5 to 2 grams of protein per kg of body weight.
- Your Sex
Generally, males have bigger muscles compared to women. This muscle size advantage is due to the higher testosterone levels in men. Testosterone promotes protein synthesis (called the anabolic effect). It also impedes protein degradation. These two effects explain why men’s muscles are more extensive compared to those of females.
Final Words
You will experience muscle decline during your exercise hiatus. However, how quickly that occurs depends on various factors. The muscle mass decline becomes noticeable after 3 to 4 weeks of break in your workout regimen. Doing two strength exercises weekly during your exercise break can help prevent loss of muscle mass. Choose an activity that hits all your key muscle groups (chest, back, triceps, biceps, quads, shoulders, glutes, calves, and hamstrings).