June 3, 2026, 6:08 pm | Read time: 5 minutes
Between the ages of 40 and 45, the body undergoes profound hormonal and biological changes–which also affects training. The body now responds differently to training stimuli. At the same time, strength training is more important than ever in this phase of life. Trainer and FITBOOK expert Alina Bock explains how to best approach this in middle age.
In midlife, our bodies begin to change. Aging processes accelerate. When and how quickly this happens is, of course, very individual. Hormones such as testosterone and estrogen decrease, while muscle loss progresses and the increase in body fat is promoted. To counteract these processes, strength training becomes essential–and should be approached smartly.
Why the Body Responds Differently to Weights in the Mid-40s
Strength training and its effects are not comparable at every age. Those who start strength training at a young age are usually rewarded with training progress in the form of rapid strength gains and muscle growth. However, those in their 40s notice that these training advances slow down and may even stagnate. This is due to hormonal changes in the body. For one, the production of testosterone, also known as the growth hormone, decreases. This makes muscle building more difficult and slows down recovery. And not only that: the body continuously loses muscle mass.
In women, the production of the hormone estrogen also decreases, which is reflected in the loss of muscle mass, slower recovery, a redistribution of fat to the abdominal area, and the loss of bone mass. The loss of muscle mass in both genders slows down metabolism. As a result, the body stores more fat.
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Why Strength Training Is More Important Than Ever in This Phase
To counteract the biological and hormonal processes of the body, strength training becomes indispensable for both men and women in their 40s. Intensive strength training with complex full-body exercises increases testosterone production and sets targeted growth stimuli. This inhibits natural muscle loss and effectively supports muscle building at the same time. Women, who are often still premenopausal in their 40s, can boost their metabolism through targeted and intensive training, strengthen the passive musculoskeletal system (ligaments, tendons, and bones), and thus effectively prevent osteoporosis and injuries in later life. The 40s are therefore an extremely important time to lay the foundation for avoiding age-related muscle and bone degeneration.
Methods to Counteract the Body’s Natural Degenerative Processes
To counteract the body’s biological degenerative processes, one should sensibly adjust their strength training.
Short and Intense Strength Training Sessions
Since recovery slows down after 40, one should not overdo it with training. It is important to plan time for recovery between training sessions. A moderate training volume is especially recommended if someone is just starting strength training at this age. In that case, one should opt for less extensive but more intense strength training sessions, interspersed with one or more recovery days.
For training sessions, I recommend complex full-body exercises. They engage many large muscle groups and also boost testosterone production and metabolism. Additionally, they simulate everyday movements that can prevent injuries in daily life. Beginners in strength training can approach basic exercises with the help of a multipress or machines.
Complex exercises that are particularly suitable include squats, deadlifts, rowing, or push-ups. Additionally, training the leg, back, and core muscles is essential to prevent injuries and pain in the back area. Exercises such as squats, leg presses, and lunges, as well as rowing, lat pulldowns, back extensions, and planks, should be integrated into the training.
To stimulate muscle growth, one should work with high intensity and a maximum repetition range of 6 to 12.
Regular Increase in Intensity
To continue setting growth stimuli and prevent muscle building from stagnating even after 40, regular increases in intensity are necessary. This can be achieved by either increasing the training weight while maintaining the same number of repetitions, reducing the number of repetitions and proportionally increasing the training weight, or by swapping certain exercises for the same muscle groups.
Protein-Rich Diet Is Important
In addition to intensive strength training, diet plays an equally important role. It must go hand in hand with training to achieve success. It is essential to consume enough protein. To maintain muscle and draw strength from existing fat reserves during training, protein intake should be at least 1.5 grams, ideally 2 grams per kilogram of body weight. This ensures the body has enough protein as so-called building blocks for muscles.
Healthy fatty acids are also important to boost metabolism and reduce inflammation processes. The ratio of omega-6 to omega-3 fatty acids should ideally be 1:1, but no more than 2:1. Since omega-6 fatty acids are already found in most common Western foods such as animal products, vegetable oils, and processed foods, they should be reduced. At the same time, it is advisable to significantly increase omega-3 intake through foods like fatty sea fish (salmon, mackerel, tuna, etc.), seafood and algae, flaxseeds and flaxseed oil, chia seeds, and walnuts. Those who have difficulty achieving the desired ratio through natural foods can use omega-3 capsules with EPA and DHA.