Building and maintaining a great body composition is a slow and difficult process regardless of your age, but as we grow older, it seems that this process gets more difficult. Is this difficulty a physiological reality that we must accept, or is it a myth worth investigating? Although there is some truth to the idea that staying fit becomes more difficult as we age, the reasons behind it might not be what you expect.

While hormonal problems do play a small role in your potential weight difficulties, the adage “if you don’t use it, you lose it” is a better explanation for the problems you face.

After a certain age, typically when you start a serious career or a family, your lifestyle becomes substantially more sedentary and your fitness goals can become less of a priority. You might have to deal with frequent business-related meals, where you can’t control your food choices. You might want to focus on your family life and will eat most of your meals with your loved ones, picking their favorite foods over fitness-appropriate foods. Your training will likely suffer too, you might end up skipping sessions because you want to spend time with your children or you need to work overtime to pay your bills.

After a certain point in life, there are very legitimate reasons that we can’t stay on top of our fitness goals. However, legitimate or not, as you keep skipping training sessions and making subpar food choices, you end up losing muscle over time replacing it with a steady cushion of fat. Month after month, you become fluffier until your physique is no longer what it used to be in your early twenties.

Furthermore, once you start losing your muscle mass, things become more difficult. You see, muscle is metabolically demanding, it burns a decent bit more calories per unit of weight than fat. In other words, as you trade fat for muscle, you face a bit of a negative feedback loop. The less muscle you carry the fewer calories you burn, the more fat you gain despite eating the same calories. Which leads to more issues such as insulin resistance, poorer nutrient partitioning, leading to more muscle loss and fat gain, so on and so forth.

To make matters worse, as you age, the problems you deal with daily tend to generate a lot more stress than the issues a typical 20-year-old deals with.  After all, taking care of a newborn can’t begin to compare with dealing with a few exams or an internship.

Although stress isn’t necessarily problematic from a physiological standpoint, your response to it can be an issue. When faced with excessive stress, you’ll likely try to find a coping mechanism, and for many of us, that can be overindulging in calorie-dense foods and drinks. 

None of these issues stem from your body directly, they are rather a byproduct of your lifestyle. However, that doesn’t mean your physiology is always on your side, far from it. 

Although it is true that men’s hormonal profile peaks in their early twenties, it does not mean that it’s akin to falling from a cliff. As the story goes, one day you are a healthy 25-year-old with peak testosterone, and the very day you turn 26 your testosterone plummets and you are hormonally undistinguishable from a woman. Reality is a bit different, the hormonal changes you’ll deal with are much more like a gentle slope. Every year your testosterone levels decrease slightly until you eventually reach a low point in your elder years (your seventies). Of course, steady or not, this decline has an effect on your muscle mass and thus your metabolism.

Women aren’t immune from this decline either, although their pattern is somewhat different. They also face a slow steady decline but at a lower rate than men; however, once they reach the pre-menopausal or the menopausal state, these changes accelerate. At that point, they can develop insulin resistance, a drop in estrogen, and a potential increase in testosterone. These hormonal changes can lead to a change in body fat distribution as well as an overall increase in weight due to a decrease in your metabolism and overall expenditure.

On top of that, if they decide to have children, women have to deal with all the unsurprising practical and hormonal changes that come with pregnancy. What might surprise you a bit more is that a women’s pregnancy can also affect the hormonal profile of their partners. There is a growing body of literature indicating that men see their testosterone decrease and their estradiol increase during their partner’s pregnancy. Since the former is associated with aggression and the latter with caregiving, it might be a change that prepares the couple to care for their newborn. 

As we have seen, not only does our lifestyle change and affect our body composition negatively, we also have to deal with hormonal changes. In other words, we are doomed, just give up; there is no point in training anymore. I’m just kidding, there is some hope for us.

Despite all the issues I mentioned before, you can actually keep most of your muscle mass well into old age if that is a priority for you. A study measured muscle mass changes in serious recreational lifters aged from 40 to 81 years old that trained at least four times per week. Believe it or not, they found no meaningful decline in their muscle mass.

Another fascinating study went a step further and directly compared the muscle growth rates of young women (21 years old on average) to older women (56 years old on average). Although there were differences in the overall muscle mass they carried at the start, there were no meaningful differences in their muscle growth rates after nine weeks of training. In other words, despite the hormonal changes we face, even if you are forty, fifty, or even sixty you can actually respond fairly well to training and grow plenty of muscle.

Although it is undeniable that it gets a bit harder to stay fit as you age, these difficulties come from lifestyle factors rather than physiological ones. Although your hormonal profile gets worse over time, it’s not enough of a change to cause significant muscle loss and weight gain. If you stay on top of your fitness and dietary habits, you can keep most of your physique well into old age.

On top of that, if you never had the chance to get started on your fitness journey, we now know that it’s never too late. You can start at any age and make meaningful progress. What are you waiting for?