MUSCLE MASS AFTER 40: WHAT CHANGES AND HOW TO STAY STRONG

After age 40, muscle mass gradually declines, often accompanied by reductions in strength, mobility, and physical endurance. Over time, these changes can become noticeable in everyday life: a full grocery bag feels heavier sooner, climbing a few flights of stairs becomes more demanding, and recovery after normal physical activity takes longer. 

Although age-related muscle changes are a natural part of aging, regular physical activity can help slow the process. Strength training is particularly important for preserving muscle mass, but to stay physically strong and capable for longer, it is best combined with aerobic exercise and mobility training. 

What causes muscle loss as we age? 

Muscle mass changes can begin earlier than many people realize, with the first signs sometimes appearing in our 30s or 40s. Research suggests that muscle mass may decline by around 3–8% per decade, with the rate of loss accelerating later in life. One reason is that, as we age, muscles become less responsive to dietary protein and physical activity – two key stimuli for muscle growth and repair. 

The nervous system’s ability to control muscles also changes with age. Some nerve connections to muscle fibers are lost, meaning these fibers may no longer be activated as efficiently as before. Over time, some fibers may become thinner or disappear altogether. Hormonal changes also play a role: testosterone levels tend to decline in men with age, while estrogen levels fall in women during perimenopause and menopause. 

Lifestyle matters too. Many people become less physically active over time, so their muscles receive less of the stimulation needed to maintain strength and mass. Prolonged sitting and insufficient strength training (also known as resistance training) can further accelerate age-related muscle loss. 

How to maintain muscle mass and strength after 40 

Regular physical activity is one of the most effective ways to preserve muscle mass and strength, with strength training playing a particularly important role. Exercises

using free weights, weight machines, resistance bands, or your own body weight help maintain and build muscle tissue. The World Health Organization (WHO) recommends muscle-strengthening activities at least twice a week. 

However, maintaining overall physical fitness requires more than strength training alone. The WHO also recommends 150–300 minutes of moderate-intensity aerobic activity or 75–150 minutes of vigorous-intensity aerobic activity per week. Rather than choosing between strength training and cardio, incorporate both into your routine. 

Tennis coach Erik Riabov, who has spent the past decade working with people of different fitness levels, also emphasizes the importance of a balanced approach: 

“Strength training helps maintain muscle mass and strength, aerobic activity supports endurance, while exercises that develop mobility, coordination, and balance help keep the body functional. The most practical approach is to combine all of these elements.” 

A balanced weekly workout plan 

According to Riabov, there is no need to train intensely every day. What matters more is combining different types of exercise while allowing enough time for recovery. For someone looking to maintain muscle mass, strength, and overall fitness, a typical week might look like this: 

• 2 strength-training sessions targeting major muscle groups. Exercises can include squats, pushing, pulling, hip-hinge movements, and core stability work using body weight, free weights, resistance bands, or machines. 
• 1–2 cardio sessions, such as tennis, cycling, swimming, or another activity that raises your heart rate and builds endurance. 
• Light daily movement, including walking, taking the stairs, and other low-intensity activities that keep you active beyond scheduled workouts.
• Mobility, balance, and coordination exercises several times a week. These can be included in warm-ups or cooldowns rather than requiring separate sessions. 

“The key isn't to overload your weekly schedule, but to create a routine you can realistically follow over the long term. For example, you might do strength training on Monday and Thursday, play tennis or do another aerobic activity on Tuesday and Saturday, and spend the remaining days walking, swimming, or simply resting. It's also important to remember that someone who hasn't exercised for a long time shouldn't suddenly start training five or six times a week. It's better to increase the workload gradually and give the body time to adapt,” says Riabov.

The best exercise is the one you enjoy 

Even the most carefully designed training plan won't deliver lasting benefits if it's difficult to stick to. That's why choosing an activity isn't just about its physical benefits, but also about finding something you enjoy enough to keep doing for years rather than weeks. 

Activities that combine physical effort with play, challenge, and social interaction can be particularly valuable. Tennis is one example. 

According to Riabov, tennis involves constant movement in different directions, changes of pace, coordination, balance, and quick reactions. Players also need to track the ball, make split-second decisions, and think strategically about their next shot. This makes tennis an excellent way to stay both physically and mentally active. 

The social aspect can also help people stay motivated: 

“People don't come simply to get a workout done. They play, socialize, try to learn something new, or simply enjoy themselves. As a coach, I see how much easier it is for people to stay motivated when exercise becomes something they look forward to rather than another obligation,” Riabov notes. 

Racket sports have also been linked to favorable long-term health outcomes. A long-term study of more than 8,500 Copenhagen residents examined eight types of physical activity: tennis, badminton, soccer, cycling, swimming, jogging, calisthenics, and health club activities. Researchers found that tennis players had an estimated life expectancy 9.7 years longer than physically inactive participants. Sports involving more social interaction were also associated with some of the most favorable outcomes. However, as this was an observational study, the findings don't establish that playing tennis itself extends life expectancy. 

When fitness becomes part of your vacation 

The long-term benefits of physical activity depend less on individual workouts and more on whether exercise becomes a consistent part of everyday life. For many people, that means staying active even while on vacation. Sports camps offer one way to combine regular exercise with relaxation, new experiences, and time away from everyday routines. 

“For people who already exercise regularly, a sports camp makes it easier to maintain their usual rhythm. For those who are still building the habit, it offers the opportunity to experience several consecutive days of structured training. The social aspect matters too – you meet like-minded people, which can make it more enjoyable to continue training together or even take part in tournaments after returning home,” says the tennis coach. 

One example is the TOUR DE MED Tennis Camp, taking place November 19–23 at Cap St Georges in Cyprus. The four-night program includes three days of training, with two tennis sessions per day led by Erik Riabov, who has experience organizing tennis camps in Lithuania and abroad. Between sessions, participants can enjoy the spa, the seaside, and other resort activities. 

For those interested in other activities, TOUR DE MED also helps plan personalized wellness journeys, from sports camps and fitness programs to retreats focused on emotional well-being and medical programs tailored to individual health needs.