What To Know About Testosterone’s Effect on Energy Levels

For many guys, having low energy isn’t simply a result of a rough night of sleep or a demanding workweek—it might be low testosterone levels at play.

Testosterone is an androgen (or male sex hormone) that’s responsible for more than just body hair growth and sex drive. It’s also a key player in how energized, motivated, and physically capable you feel.

But how can you know if your feelings of low energy could be an effect of low T? Below, learn about testosterone’s effect on energy levels, signs and symptoms of low testosterone, and what you can do to recharge.

There’s a huge connection between testosterone and energy. In fact, one of the hormone’s key functions is to help your energy engine run smoothly.

One way it does this is by supporting the function of mitochondria, which you may remember from high school bio as “the powerhouses” of your cells that are responsible for energy production. When testosterone levels are optimal, cellular mitochondria can more efficiently convert nutrients into energy, helping you feel more alert and capable throughout the day.

Testosterone also supports the production and development of red blood cells, which are necessary for oxygen delivery. More efficient oxygen delivery can translate to improved endurance and quicker recovery—i.e., less of that “hit a wall by 2 p.m.” feeling.

Low levels of testosterone, on the other hand, can leave you feeling like your body’s in power-saving mode, especially if you have a true deficiency.

In this case, you may also experience some psychological side effects of low testosterone, which can include impacting brain chemicals like dopamine, a neurotransmitter that influences your motivation, decision-making, and mental energy. However, as current research on testosterone levels and dopamine focuses on rats, additional human data is needed in order to fully explore this connection.

We all have “off” days, but if you're starting to feel like you’re constantly in nap mode, the culprit might be more a bout of stress or a packed schedule. Low testosterone can quietly drain your physical and mental battery.

Here are some signs that your persistent fatigue might be hormone-related:

• Chronic tiredness. You’re catching zzz’s, but you still wake up feeling like you just pulled an all-nighter, because the sleep was disrupted or simply just not great.

• Low motivation. Things that used to fire you up, like hitting the gym, pursuing work goals, or having a passion for new hobbies, start to feel like a chore.

• Reduced physical endurance. Workouts feel harder, recovery takes longer, and you don’t have the same stamina you used to—for no obvious reason.

• Brain fog. Struggling to concentrate, remember details, or stay sharp? It could be testosterone levels, which is involved in your mental clarity.

• Mood changes. Irritability, low mood, or a sense that you're just “not yourself" might also show up when T levels are down.

It’s important not to self-diagnose, but if you’re noticing any of the symptoms above, it may be worth talking to your healthcare provider about hormonal health. They may recommend testing your testosterone levels, which can inform the most appropriate treatment recommendations.

If blood tests confirm that you have low testosterone, one possible strategy for restoring your levels might be testosterone replacement therapy (TRT). While not an instant fix, TRT can make a noticeable difference for men with diagnosed hypogonadism, a condition in which the body doesn’t produce enough testosterone.

Studies have demonstrated the benefits of testosterone therapy for many guys with low T, which affects up to an estimated 39 percent of men over age 45. For instance, TRT can help restore energy, mood, sense of well-being, and even muscle strength in men whose testosterone levels register below the normal range.

For those who experience restored T levels as a result of TRT, effects may include better sleep, and improved sexual function.

However, TRT isn’t a perfect option for everyone.

For instance, the intervention is not recommended for men with normal testosterone levels. Boosting testosterone levels to surpass what your body needs doesn’t improve energy and can come with risks and side effects, like:

• Skin changes, like acne or oily skin

• Fluid retention

• Increased red blood cell counts, which is called polycythemia, a condition that can thicken blood and raise the risk of blood clots

• Worsened sleep apnea

• Reduced fertility, due to suppressed natural testosterone and sperm production

TRT should always be administered under medical supervision, with regular labwork and follow-ups to make sure your body is responding safely and appropriately.

You don’t necessarily need a prescription to support healthy testosterone levels. Sometimes, positive lifestyle changes are all you need to see significant improvements in your quality of life.

Here are some research-backed, natural ways to increase your testosterone and boost energy levels at the same time:

• Lift weights and get moving. Resistance training is one of the most effective temporary natural testosterone boosters. High-intensity interval training (HIIT) can help, too. Just don’t overtrain, as doing so can have the opposite effect on your T levels.

• Prioritize quality sleep. Your body produces most of its testosterone during deep sleep. Skimping on rest can cut those levels short. Aim for seven to nine hours per night.

• Eat better. A healthy diet packed with nutrients like zinc (found in pumpkin seeds, lentils, and nuts), vitamin D (hello, sunshine, certain fish, and fortified foods), and healthy fats (avocados, olive oil) is essential for male fertility and testosterone production. Avoid ultra-processed foods, which aren’t great for reproductive health.

• Maintain a healthy weight. Weight gain and excess body fat, especially around the midsection, is linked to lower testosterone. Dropping even a few pounds may help you restore more optimal levels.

• Manage your stress. Chronic stress jacks up cortisol, a hormone that can suppress testosterone if it stays elevated. Prioritize your mental health with habits like meditation, deep breathing, or spending more time outdoors.

• Limit alcohol and endocrine disruptors. Heavy drinking and exposure to certain chemicals (like BPA in plastics) can interfere with testosterone.

By adopting some or all of these lifestyle tweaks, you might not only notice improvements to your energy levels but also to your overall well-being. If you do experience sustained low energy, make an appointment to visit a healthcare provider to talk about your symptoms.

Testosterone isn’t the only factor that plays into how energized you feel—but it certainly has an influence. Here’s what to remember:

• Testosterone plays a major role in how energized, motivated, and physically capable you feel by supporting mitochondrial function, oxygen delivery, and brain chemistry.

• Low testosterone is associated with fatigue, reduced endurance, and mental fog—but it’s not the only cause of tiredness. Proper hormone testing is key for landing on a diagnosis and treatment.

• TRT can be effective for some men with clinically low T, but lifestyle strategies like strength training, sleep, and nutrition are powerful tools for everyone.

Ready to reclaim your energy? Chat with your provider if you suspect you may be experiencing low testosterone—or if you could use help navigating your symptoms.