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Physical Changes for Men at 40


Article at a Glance

  • Men in their 40’s encounter a myriad of physical changes that may seem inevitable.
  • Men generally see and feel these changes all over their body and, if gone untreated, this should be expected.
  • Many of these age-related physical changes can be well monitored, controlled, and even treated.

Let’s look at the physiology behind some physical changes you may be noticing in your 40’s and some research-backed solutions that can help you effectively delay those changes.

Some of the signs associated with the often highly-feared aging process are raying hair, loss of energy, decline in height, sexual dysfunction, weight gain, and overall decline in health.

The rise of these symptoms is due to underlying physiological processes occurring in the body with age that can often be controlled or mitigated. Some of these underlying causes start in your 40’s. Being able to anticipate and understand them can give you a sense of control over the aging process.

Benign Prostatic Hyperplasia

In general, men’s prostates start slowly growing with age, usually around 25, leading to a non-life-threatening condition called benign prostatic hyperplasia (BPH). Prostate enlargement occurs when prostatic cells multiply and gradually create pressure on the urethra. The cause is unknown, but age-related hormone imbalance is suspected to play a large role.

BPH is a considerable health problem in aging men due to its symptoms and complications. It is the most common cause for lower urinary tract symptoms and bladder obstructions. This can result in frequent urination, difficulty starting to urinate, straining while urinating, and non-continuous urinary stream [R].

There are many treatments available for BPH, including medicines and minimally invasive surgical therapies. If you are experiencing these symptoms, please consult your physician.

Mitochondrial Dysfunction

Mitochondria are the cells’ energy source. Without them, cells would not be able to extrapolate energy from carbohydrates, fats, and proteins.

Unfortunately, there is an age-related decline in their functioning, particularly in heart and muscle tissue [R]. This decline includes changes such as reduced mitochondrial content, altered morphology, reduced activity, and increased formation of reactive oxygen species – all of which ultimately lead to organ aging and dysfunction. In fact, it has been shown that mitochondrial dysfunction precedes the two main causes of physical decline in aging men: sarcopenia and heart failure [R].

However, there are ways to improve mitochondrial functioning. One way is through exercise, specifically high-intensity interval training (HIIT) and resistance training (RT) [R]. HIIT and RT were shown to reverse the age-related decline in muscle mitochondria, thereby reducing the risk of muscular aging.

Another increasingly popular method to increase mitochondrial function is through the upregulation of nicotinamide adenine dinucleotide (NAD). NAD is a compound crucial for mitochondrial function that declines with age. It can be increased in the body through supplementation with its precursors, nicotinamide riboside (NR) or nicotinamide dinucleotide (NMN). This offers an anti-aging effect [R].


Physical Changes Men at 40 sarcopenia aging

A common aging byproduct is sarcopenia, or loss of muscle mass. By age 40, men usually have lost 1-5% of their muscle mass, caused by the gradual loss of muscle cell function [R]. This loss accelerates with age and, when left unmonitored, results in fragility and interference with physical activity.

Factors that affect the development of sarcopenia with age include:

  • Low protein intake
  • Lower concentration of growth hormones
  • Decline in ability to extrapolate energy from protein
  • Decreased function of motor neurons
  • Mitochondrial dysfunction
  • Sedentary lifestyle

Growth hormone replacement therapy has been shown to prevent sarcopenia by improving protein balance and antioxidant defenses [R]. Physical exercise is also scientifically proven to manage and even prevent sarcopenia [R].

Decline in Brown Adipose Tissue Activation

There are two types of adipose tissue in humans, white and brown. While adipose tissue (WAT) stores energy, in the form of fat, and brown adipose tissue (BAT) dissipates it.

BAT is the major site involved in non-shivering thermogenesis, or heat production. It contributes to the control of body temperature, energy expenditure, and BMI [R]. With age, BAT activity declines, leading to age-related adiposity, or fat accumulation [R]. One study showed that the activity of BAT was more than 50% in young individuals (between 20-29 years old) and less than 10% in individuals older than 40 years old.

So how can one increase their BAT activation and therefore avoid age-related weight gain? BAT activation increases rapidly after cold exposure [R]. Cryotherapy is, therefore, an effective method to increase BAT activation, thereby reducing age-related weight gain [R].


Physical Changes Men at 40 baldness

Alopecia, or male pattern baldness, often starts between your 30’s and 40’s. It is a result of both hormonal changes that occur in men with age, such as a drop in testosterone, as well as inherited genes [R].

There are some effective FDA-approved treatments such as Minoxidil and Finasteride, if a man desires to improve his progressive hair loss. Minoxidil works to promote hair growth and comes in either solution or foam form. You can find it over-the-counter at pharmacies or supermarkets. Finasteride is a drug that also works to promote hair growth, but you’ll need a prescription from a health care provider [R].


Age-related hyperkyphosis is the exaggerated curvature of the upper part of the spine. This creates the hump on the back we often associate with the elderly. People of all ages have a natural curving of the spine, but the angle increases with age. Between childhood and the 30’s, the normal angle is about 20° to 29°. After the age of 40, the angle begins to increase, in both males and females, although more rapidly in females [R].

As the angle of the spine increases, quality of life and physical performance often decline, making early intervention crucial for longevity.

There are no medications known to improve hyperkyphosis, unfortunately. However, yoga has been shown to be a promising remedy and it also serves as a prevention method [R].

Immune System Decline

Physical Changes Men at 40 immune system

Aging leads to immunosenescence, or reduced efficiency, of both parts of the immune system: the innate immune system (the first line of defense) and adaptive immune system (the second, more specialized line of defense).

Compared to young adults, middle-aged men typically have higher levels of inflammation. This puts these individuals at an increased risk for diseases like cardiovascular disease, diabetes, obesity, and cancer. This reduced immune efficiency also contributes to the delayed injury repair observed with age [R].

However, the extent of immune aging is also highly dependent on stress levels as stress, and particularly chronic stress, has been shown to exacerbate immune aging [R]. So one way to reduce the effect of aging on the immune system is via the reduction of stress.

Nutrition is also a powerful weapon against immune aging. Supplements such as zinc, vitamin E, and probiotics effectively improve immune function [R]. Calorie restriction is another diet alteration that aids in delaying age-related decline in immunity [R]. Calorie Restriction is a strict diet of reduced caloric intake that is well-documented for its anti-aging effects, but should be monitored by a professional.

Hormonal Changes

Testosterone levels begin to decline at a steady rate of 1-2% per year between a man’s third and fourth decades [R]. This is not the only endocrine compound that is affected by aging, though it is of high concern for aging men. There is also a decrease in Dehydroepiandrosterone (a testosterone precursor), growth hormone, and melatonin, and an increase in follicle stimulating hormone, luteinizing hormone, cortisol, and estradiol [R].

Other hormone levels may remain stable, like insulin, but their receptors become less sensitive with age, which means they are less functional. Exercise, supplementation, and hormone replacement therapies can all help control these hormonal changes.

Decrease in Sperm Quality

Studies have consistently demonstrated that there is a positive relationship between a man’s age and the time it takes for their female partners to get pregnant. In addition, increased male age is also linked to decreased pregnancy rates [R].

These effects are due to the decrease in sperm quality with age, affected by the hormonal changes described above, which are most pronounced after the age of 45. Alterations in semen observed in aging men include lower sperm concentrations, low motility, decreased morphology, low seminal volume, and DNA fragmentation in sperm cells [R].

There are some scientifically backed methods to improve male sperm quality, and therefore fertility, including supplements of D-Aspartic acid [R], vitamin D [R], vitamin C [R], and zinc [R]. In addition to supplements, exercise has also been proven to improve semen parameters [R].

Sexual Dysfunction

Hormonal changes with age also naturally lead to sexual dysfunction, since hormone balance is crucial to sexual functioning. Sexual dysfunction includes changes in sex-related variables such as satisfaction, erectile frequency, and sexual desire.

Changes in sexual functioning start in middle-aged men and become more pronounced with age. For example, by 40, men tend to experience 3 fewer erections per month [R].

The keys to improving sexual functioning lie in hormonal balance and stress relief. Testosterone and DHEA supplementation can improve age-related sexual dysfunction, as can vitamin supplements such as vitamin D, zinc, and D-Aspartic Acid, mentioned above, which often act by increasing serum testosterone levels. Increasing testosterone is crucial in improving sexual functioning [R].

Daily stress also negatively influences sexual functioning [R]. Meditation and yoga are research-backed ways to relieve stress, and should, therefore, be considered for improved sexual functioning [R].


The 40’s come with a myriad of physical changes that may seem inevitable. However, many of the age-related physical changes you experience can be well monitored, controlled, and even treated.

In our directory of health and longevity clinics, you can browse through and find the right clinic and solutions to assist you in managing the aging process.

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