Hopefully, you won’t choose to stop lifting weights. Resistance training has too many benefits not to make it a permanent part of your life. Still, there may be times when you have to take a break due to illness, injury or surgery. Naturally, you worry about losing all of your hard-earned strength gains. What happens to your muscles when you stop lifting weights? Will you quickly lose the strength you worked so hard to get?
There’s a common misperception that muscle turns to fat when you stop lifting. This is definitely not the case. Muscle can’t turn to fat. They are two distinct types of tissue. What happens is muscle mass decreases from lack of overload and fat tissue increases. Remember, having more muscle means you have a higher resting metabolic rate. Plus, once you stop lifting weights your calorie requirements go down. Keep eating the same way and you’ll put on body fat. Muscle loss + fat gain = looking pudgier.
How Quickly Do You Lose Fitness Gains When You Stop Lifting Weights?
Loss of fitness benefits when you stop lifting weights is called detraining. You lose aerobic fitness more quickly when you stop training than you do strength gains. In fact, you begin to lose aerobic capacity as early as 10 days after you stop training and by 3 months you’ll have lost as much as 50% of your aerobic gains. This is primarily due to a decrease in blood volume as a result of not training.
Over time, other changes occur – stroke volume, the amount of blood your heart can pump per beat, declines, muscle capillary density decreases and the number of energy-producing mitochondria in muscle cells goes down. As a result, your muscles can extract less oxygen and produce less ATP at a given level of exercise – so your endurance decreases. Research shows fitter people who have exercised for a while lose their aerobic fitness gains more slowly than people who have trained for shorter periods of time.
What about the loss of strength gains when you stop lifting weights? In one study, male powerlifters that stopped lifting for two weeks lost 12% of their muscle strength and almost 7% of their fast-twitch muscle fibers. Fast-twitch muscle fibers are the ones that increase in size as a result of strength training. They’re the fibers you primarily use for strength and power moves. Muscle power is lost more quickly than muscle strength.
Other research shows minimal losses in strength during the first 2 to 4 weeks of detraining. It’s safe to say that you probably won’t have a major loss of strength during the first month after you stop lifting weights. After the first month, there is a gradual loss in strength with as much as a 12% loss in strength by 3 months.
What you lose more quickly is muscle endurance. If you quit training for two months, you’ll lose as much as 40% of your muscle endurance. What about muscle mass? One study showed only a slight decrease (about 6%) in muscle fiber cross-sectional area after 3 weeks of no training.
If strength losses are minimal when you stop lifting weights for 4 weeks, why do people lose muscle mass and strength so quickly when they wear a cast? When you wear a cast the muscle is completely immobilized. Under those conditions, muscles atrophy quickly. When you stop resistance training the muscle still has free movement. Under these conditions, you lose strength much more slowly.
Regaining Strength after a Training Layoff
Here’s the good news about detraining. You can strength train as little as once or twice a week and still maintain your strength gains. It takes hard training to develop strength but once you’ve developed it you can maintain it with as little as one strength-training session per week.
There’s more good news. Your muscles have a certain amount of “memory.” Muscle memory allows you to regain strength quickly after you start training again. One theory is in response to strength training muscle fibers develop new nuclei. Even when you stop lifting weights those nuclei remain. Once you resume training these nuclei are ready to synthesize new proteins.
Another theory is muscle memory is a brain-related phenomenon. Your brain “remembers” how to turn on those muscle fibers and can do so faster when you return to training. Most of the recent evidence points to the first theory being more likely. Regardless of why muscle memory occurs, it’s easier to get strong the second or third time around.
How to Apply This to Your Training
There are times you may not be able to train for weeks or even months at a time. You can prevent loss of muscle strength by training at least once a week. If you can’t do that you’ll lose strength but the losses probably won’t be substantial until you haven’t trained for 3 months or more. Plus, when you begin training again re-developing the strength you lost will occur quickly due to muscle memory.
When you start training again after a long break, don’t jump back into lifting at the same intensity you were. Start by doing muscle conditioning exercises using lighter weights for a week or more. Circuit training using a weight that’s around 50% of your one rep max is a good way to ease back into training or simply use lighter weights and do more reps. Once you’re better conditioned, begin gradually increasing the weight. Detraining reduces muscle endurance and can even affect your stability and balance. This increases your risk of injury. That’s why it’s safest to start with general conditioning exercises after a break.
As you can see, taking a few weeks or even a month or two off won’t greatly reduce your strength but it’s always best to continue training even if you have to cut back to once a week.
References:
Med Sci Sports Exerc. 2001 Mar;33(3):413-21.
Sports & Exercise, 32(8):1505-1512, August 2000.
Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining. J Appl Physiol 70, 631-640.
Exercise Biology. “Muscle Memory Solved”
Related Articles By Cathe:
4 Reasons We Lose Strength as a Result of Loss of Muscle as We Age
Lack of Exercise Is Even More Harmful to Your Muscles as You Get Older
Do You Have to Lift Heavy Weights to Build Muscle?
Related Cathe Friedrich Workout DVDs:
STS Strength 90 Day Workout Program
All of Cathe’s Strength & Toning Workout DVDs
Total Body Workouts
Lower Body Workouts
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