We've all been guilty of skipping a workout… fine, several. Eventually, we make our way back to the gym, but it seems like the treadmills have gotten faster and the weights have gotten heavier. Is it just our guilty consciences psyching us out, or did we truly lose our hard-earned strength? Here, we explain just how long it takes to lose muscle mass and strength, and what to do stop it from happening.
Dude, Where's My Muscle? -- Why It Matters
To understand what's going on, we need to look inside the body. One study on rats found that just 48 hours after exercise, the body hits a lower steady-state rate of protein synthesis and stops building and repairing muscle. Sure, rats and humans are different, but the study could have interesting applications to human musculature. Immobilized muscles lie dormant and waiting for use (who knew they could be so lazy?). The muscles aren't getting any stronger -- but they're not wasting away, either.
There are several factors that can lead to muscle atrophy:
Age: Regardless of how often we make it to the gym, the natural process of aging can cause muscle loss. Sarcopenia, or muscle loss due to aging, kicks in as early as age 20. The rate of sarcopenia picks up as we age; by the time we get to age 50, a person can lose 0.4 pounds of muscle every year.
Diet: While it's generally thought not eating enough causes muscle loss, recent studies have found rats that were fed fewer calories over the course of 30 months showed improved protein synthesis and muscle activity compared to their cohorts that were placed on a higher calorie diet. While calorie restriction might not support optimum performance, this research suggests it could preserve greater function as we age. What you eat also matters, as malnutrition can contribute to sarcopenia.
Sleep: Because sleep debt decreases the rate at which the body builds and repairs muscle, skipping sleep to hit the weight room can neutralize results. Full recovery from workouts is critical to making (and maintaining) progress.
Results May Vary? -- The Answer/Debate
How much and how fast muscles atrophy, or lose mass, depends on the muscle. Antigravity muscles that hold us up (e.g., hamstrings) atrophy slower than muscles used for specialized sports or exercise, especially when those muscles are severely limited such as in bed rest, limb suspension, or complete immobilization. Of course, these results are likely to not be as pronounced for a brief break from training. All muscles atrophy with extreme disuse. Skeletal muscles, which include antigravity muscles, are voluntary muscles used to move the body. These are generally more susceptible than involuntary muscles such as cardiac muscles, which help power the heart even when you’re asleep. This helps explain why muscle loss occurs faster for "highly trained individuals" with more specialized muscle groups than for "exercise newbies" even though they may be in better overall shape. There are, fortunately, proven ways to speed recovery regardless of fitness level.
Taking a break can also impact muscle function. While flexibility and power decrease substantially after just one week of inactivity, endurance will decline after two weeks. General muscle strength is usually maintained for at least the first month of inactivity. And even a year after quitting a 12-week strength training program, up to 55 percent of the original strength gain is maintained! Now there's motivation to try, try and try again.
One last piece of great news if you're feeling guilty about taking a break: Muscle memory actually makes it easier to regain strength than it was to build that muscle the first time. So whether that gym membership expired, you got sick or a dog ate those gym shoes (eww!), climb back up on that horse and keep on keeping on!
Preventing Atrophy -- Your Action Plan
There's no easy way to prevent loss of muscle mass and strength. Here are some ways to keep up a daily routine and avoid lengthy training breaks.
Eat Right: Just like great abs are said to be made in the kitchen, it's critical to eat healthy foods in the period immediately following a workout. While results are inconclusive as to whether eating more protein, specifically, can prevent muscle loss, a balanced diet helps ensure that muscles get the amino acids, vitamins, and minerals they need to build and stay strong.
Start Early: We can’t control aging, but a recent study found that recreational athletes who consistently worked out four to five times each week were able to "freeze" levels of muscle mass as they aged — thereby avoiding the brunt of the effects of sarcopenia. It's no cryogenic deep freeze, but generally, the sooner we start an exercise regimen, the sooner our muscles will make like Austin Powers and "freeze."
Work it Hard: When hitting the gym, remember to "go hard or go home" and build those muscles as strong as possible. Because loss occurs gradually, the fitter the muscle, the longer it will take to hit ground zero.
What are your tips for staying fit even on exercise breaks? Let us know in the comments!