It’s rare to watch a sporting event on television and not see a commercial advertising a product claiming to elevate testosterone (T) levels in men. After the age of 35, many men experience something called andropause, which causes their bodies to produce 1 to 3% less T per year—that is, unless they do something to elevate production of the hormone. What’s worse, excessive levels of adipose tissues in the abdominal region (i.e., belly fat) can increase the production of aromatase, an enzyme that can convert T to estradiol, the female sex hormone that promotes the growth of breast tissue. While pharmacological solutions, like the ones advertised during televised sports, are available, exercise—specifically resistance training and high-intensity cardiorespiratory exercise—can elevate T levels as well. 

Arguably, today’s middle-aged and older adults are more motivated to maintain their health and vitality—and for longer—than previous generations. As a health and exercise professional, it is essential that you understand how exercise influences T so you can design workouts to help older male clients elevate their T levels and maintain or even grow lean muscle mass. When asked about the relationship between T and the aging process, Dr. Jim Stray-Gundersen, an exercise physiologist, notes, “When T levels decline, it could accelerate the aging process. Therefore, resistance training becomes an important intervention.” 

Understanding how to apply the science will give you the ability to design workout programs that could help older male clients maintain testosterone production and muscle mass well into the later years of life.

The Different Types of Hormones

Hormones can be classified into three specific types: steroids, peptides and amines. Each one has a unique chemical structure that determines how it interacts with specific receptors. Steroid hormones work with specific receptors in the nucleus of a cell. Peptide hormones are comprised of amino acids and interact with receptor sites on a cell’s membrane. Amines contain nitrogen and influence the sympathetic nervous system, which controls energy production for exercise. Some hormones, like testosterone or human growth hormone, are classified as anabolic because they promote tissue growth. Catabolic hormones, on the other hand, break down structures into smaller components. For example, cortisol and epinephrine are catabolic hormones that support the use of free fatty acids for energy metabolism (Kenney, Wilmore and Costill, 2015). 

Mechanical stress is the physical damage to individual muscle proteins that results from resistance training to the point of fatigue. Exercising to the point of fatigue can also cause metabolic stress by depleting the amount of carbohydrates available for energy in muscle cells. T is an anabolic steroid hormone that is released by the Leydig cells of the testes in men, the theca cells of ovaries in women and the adrenal complex in both sexes in response to both mechanical and metabolic stress (Schoenfeld, 2021; Kenney, Wilmore and Costill, 2015). T is involved in hair growth on the body and face as well as in the development of secondary sexual characteristics during the maturation process in males. For the purposes of this article, however, we’ll focus on the exercise-related functions of T. 

The Role of Testosterone in Muscle Growth

Hormones have both short- and long-term responses to exercise; T is a completely natural substance derived from cholesterol that promotes muscle growth as part of the normal post-exercise recovery process. In the acute phase immediately following a resistance-training session, T promotes the uptake of amino acids for protein metabolism, the production of new satellite cells and the release of growth hormone by the pituitary gland, all of which help to repair muscle fibers damaged by exercise. T is fat-soluble and its receptors are in the nucleus of the cell. After an exercise session, T has to cross the cell membrane to attach to the receptor sites, where it stimulates muscle protein synthesis and the production of new satellite cells to repair the damaged muscle fibers. It’s this role that makes T an integral component of increasing lean muscle mass (Schoenfeld, 2021). 

High-intensity exercise stimulates the hypothalamus to send a signal to the testes to increase T production; as a result, circulating levels of the hormone are elevated for up to 30 minutes after exercise. T cannot be stored in the cells that make it; once produced, it will attach to a binding protein to be carried through the blood to muscle cells, where the hormone leaves the carrier and passes through the membrane of the cell to act with androgen receptors on the nucleus of a cell (Kenney, Wilmore and Costill, 2015).

Resistance training for the larger muscle groups can elevate the amount of T immediately after exercise. However, it is the long-term application of high-intensity resistance training that results in an increase in the receptor sites and binding proteins, which, in turn, allows T to function more efficiently. Resistance training seems to have a greater influence on T levels in males than females. Because a majority of T is secreted in the testes, women produce 10 to 20 times less T than men, which means the common concern about developing “bulky muscles” as the result of resistance training is relatively unfounded (Schoenfeld, 2021). Additionally, a study that involved men and women following the same resistance-training program revealed that while the workouts increased T in males, the females did not experience a change in T levels.  

Exercise Programs to Boost Testosterone in Male Clients

When asked for advice on how to elevate T levels, Dr. Stray-Gundersen believes drugs are unnecessary. “There is no need to mess with Mother Nature,” he asserts. “Heavy resistance training can be one of the most effective methods for promoting T production.” Exercise programs to elevate T levels in male clients should focus on multiple sets of strength training performed to the point of fatigue. A review of the research on how exercise influences hormone levels found that resistance training causes four specific adaptations to T production: (1) long-term changes that increase resting levels; (2) long-term changes in how efficiently the body produces T; (3) changes during and within the first 30 minutes post-exercise; and (4), most importantly, an increase in the number of receptor sites in muscle cells that interact with T. Increasing the number of receptor sites means that post-exercise there is a better chance that elevated levels of circulating free T will have an effect on muscle growth. Based on their review, the researchers concluded that high-intensity strength training involving large amounts of muscle mass combined with relatively short rest intervals of one minute or less for a high volume of sets and reps stimulates T production. “Manipulation of the acute program variables,” they wrote, “ensures an optimal neuroendocrine response.” 

Research suggests that resistance training can help older men increase T levels. In a study by Baker and colleagues, three groups of men were divided according to age: 20 to 26 years, 38 to 53 years and 59 to 72 years old. All three groups performed the same strength-training program consisting of six exercises using 80% of one-repetition maximum (1-RM) for three sets of 10 repetitions. Each group had blood drawn before and after the workout to measure how the exercise influenced T production. Prior to the workout, the younger group had a higher level of T compared to the two older groups, but all three groups showed an increase in T after the workout. According to the researchers, “Middle-aged and older men showed similar relative T responses to those of younger men to a single bout of high-intensity resistance-training exercise.”

In a separate review of the research literature, Vingren and colleagues noted that heavy strength training promotes both total T and free T (the levels of the hormone circulating through the bloodstream that can attach to the binding proteins responsible for carrying it to receptor sites in the nuclei of muscle cells). One study referenced in the review found that performing multijoint, compound movements involving larger muscles in the initial phase of an exercise session (after a warm-up) can elevate T levels, which helps to stimulate growth in smaller, single-joint muscles when they are used during isolation exercises later in a workout. Echoing previous research related to the production of T, Vingren and associates suggested that exercise selection should focus on compound movements with shorter rest intervals. “Hormonal changes appear to be related to the amount of muscle mass activated,” the researchers noted, “and to the metabolic response caused by the exercise.”

Resistance training is not the only mode of exercise that can stimulate T production for older individuals; there is evidence to indicate that high-intensity interval training (HIIT) can also elevate levels of free T. Researchers recruited 22 males between the ages of 60 and 64 years who had a history of sedentary behavior. During the six-week study, participants performed a total of nine HIIT workouts on a bicycle ergometer, with each workout consisting of six 30-second sprint intervals followed by three-minute recovery intervals. Despite a lifelong history of being sedentary prior to the study, the participants experienced, on average, a 17% increase in T levels. “HIIT appears a sufficient stimulus to improve free-T in lifelong sedentary aging men,” observed the study authors. 

These findings and those presented earlier suggest that, when it comes to helping clients elevate their T levels, the programs you design should feature resistance training using multijoint compound movements for large muscle groups early in the workout combined with repetitions to the point of fatigue and relatively short (fewer than 60 seconds) rest intervals. The overall duration of the workouts should be relatively short (45 minutes or less), and cardiorespiratory exercise should focus on HIIT to ensure an optimal environment for T production. The table below presents a sample workout that you can use with your middle-aged and older-adult male clients who are interested in elevating their T levels. Three to four sets of each exercise should be performed at an intensity of 10−12 RM (meaning that the weight should be heavy enough to cause fatigue after 10 to 12 repetitions), with a rest interval of 45 to 60 seconds between sets.

After the Workout

Too often, the most overlooked variable of any exercise program is the post-workout recovery period. When clients work at an intensity high enough to stimulate T production, they should follow a specific strategy to help promote the recovery necessary for optimal muscle growth. Sleep is the time when other anabolic hormones, such as growth hormone, are produced to help repair damaged tissues. For best results, communicate the need for clients and group workout participants to get a full night’s sleep on the nights following a really challenging exercise session.