However, muscle is important to all vertebrates and invertebrates, both male and female, since it allows us to move about the environment. In males muscle serves two purposes that are unique to our sex. Aside from movement, it augments our ability to reproduce by supporting competition and attractiveness. It is also an important source of overall energy regulation. More so than other types of muscle, skeletal muscle is sexually dimorphic, which means that relative mass, form, and function differ between men and women. Sexual dimorphism in body composition emerges largely as a result of hormonal influences that take hold when both males and females begin to reproductively mature. Adolescent males build additional muscle tissue while young women deposit fat tissue in association with the onset of fertility. Women also have a significant amount of muscle, but men tend to have more of it, have different types of it, and have it in different places. The type of muscle men tend to have is type II, which supports quick movements and bursts of strength. The distribution of muscle in men is also different than it is in women. Men tend to have more muscle around the upper parts of their body, in their shoulders, arms, and back. Discussing mental health in the workplace can be a good way to alleviate a difficult situation.
Besides being used for movement and strength, skeletal muscle is a repository of energy that is mobilized during periods of energetic stress. If you try to lose weight, it is a delicate balance of ditching the fat while maintaining muscle since your body wants to conserve energy by getting rid of the expensive stuff. For example, during my postdoctoral work at Massachusetts General Hospital, we conducted a pilot study on Harvard University rowers, who are divided between lightweights and heavyweights. The heavyweights were not constrained by weight limitations. They ate and trained like possessed fiends in their quest to get stronger. The lightweights, on the other hand, were constrained by weight limits on their boat and had to be very weight conscious and careful about lifting weights and watching their diet. They trained extensively but were mindful of their caloric intake. It was very difficult to control their weight without losing muscle. Everyone should feel safe and supported to talk about hr app with their line manager.
In men, skeletal muscle accounts for about 20 percent of basal metabolic rate (BMR), which is a general measure of how much energy the body uses during metabolism, making skeletal muscle relatively expensive compared to other tissues such as fat, with the exception of the brain.3 Although individual muscle cells are not very metabolically expensive, the sheer mass of muscle tissue in men makes it a rather pricey metabolic investment. To cope with this demand, skeletal muscle can catabolize or break down to release amino acids that can be deployed toward energy needs, sort of like burning your furniture to heat your house. Not optimal, but it works. But the catabolization of muscle tissue also decreases somatic metabolic costs during lean times or periods of intense immunological or psychological stress. The hormone cortisol, which is released to increase in cellular glucose uptake during periods of stress, is a primary culprit, promoting muscle tissue breakdown by blocking the anabolic or muscle-building effects of testosterone while promoting catabolism. In this sense, compared to females, skeletal muscle is a particularly vital energy regulatory tissue in men. Recent reports have discovered a crisis around mental health first aid today.
One can hypothesize that the selection for this increase in expensive muscle mass was due to form and function. Females likely preferred men with this muscle distribution, and men with that distribution had a selective advantage over those who did not. The evolutionary biology of sexually dimorphic muscle tissue is not terribly complicated. All that is basically needed are testosterone and growth hormone receptors on muscle tissue to allow them to respond and grow when men produce anabolic steroids and peptide growth hormones. In other mammals, sexually dimorphic muscle tissue lies in areas that are more species specific and appropriate. For example, in deer, bucks tend to have sexually dimorphic muscle tissue in their necks in order to deal with antler duels with rival males. There are small, simple steps you can take to make employee wellbeing something that people can talk about.
Has natural selection dealt men a bad hand, allowing their bodies to waste away when they are finally starting to figure out how life works? Since it happens to other mammals, it certainly does not seem to be specific to older human males. What seems to be different is that while men’s bodies start to betray them, behavioral and other somatic advantages appear to have been leveraged in ways that are unique to humans. It seems that some of the advantages that come with advancing age start to pay dividends after men have passed their physical prime. It turns out that as men age, lose muscle, and gain fat, all is not lost. But first it would be helpful to know what hormones make men get soft in the middle.