Testosterone and strength training – what do you need to know to make progress?

Testosterone and muscles – how does it really work?

Testosterone supports muscle mass development primarily by influencing muscle protein synthesis. When hormone levels are within the normal range, the body is better able to repair and strengthen muscle fibres after exercise – which directly translates into faster strength gains and better recovery between sessions.

With a testosterone deficiency, even with regular and intense resistance training, muscle mass increases more slowly, and maintaining your current strength can be noticeably more difficult. This is one of the most common reasons why progress suddenly stalls – even though the training plan and diet appear to be on the right track.

Important note: a normal testosterone level alone will not build muscle without the right training stimulus. Resistance training, an adequate protein intake, sleep and time for recovery are essential. Testosterone acts as an enhancer of these processes – it does not replace any of them.

Does strength training increase testosterone levels?

Yes – but it depends on the type and intensity of the exercise, as well as the quality of your recovery.

Strength training targeting large muscle groups

Research shows that intense but relatively short resistance training sessions – particularly multi-joint exercises that engage large muscle groups (squats, deadlifts, bench presses), performed in sets of moderate to high intensity – lead to a temporary increase in testosterone levels after exercise. This increase occurs immediately after training, after which hormone levels return to baseline values.

Prolonged exertion without recovery

Conversely, long-duration endurance training – cardio sessions lasting several hours, marathons, triathlons – without adequate recovery is associated with a reduction in resting testosterone levels and hormonal imbalances. Importantly for men who combine gym training with cardio: the testosterone-to-cortisol ratio (T/C) is sometimes used as an auxiliary indicator of the body’s stress load, but it is not a standalone criterion for diagnosing overtraining.

Overtraining – the silent enemy of progress

Prolonged training overload combined with insufficient rest can lead to overtraining syndrome. The effects include chronic fatigue, a decline in performance, poorer recovery and possible adverse changes to the hormonal profile – including a reduction in testosterone. Paradoxically, more training sessions can lead to poorer performance and reduced levels of the very hormone that was supposed to support that performance. The solution is to reduce the training load, improve energy balance and schedule rest days.

More testosterone = better results at the gym?

This is one of the most common myths in the fitness world. The answer is: no.

It is important to maintain normal testosterone levels – both chronic deficiency and excess can be associated with adverse health effects. Artificially elevated levels, most commonly resulting from the use of anabolic steroids or other forms of androgenic doping, can lead, amongst other things, to abnormal lipid profiles, cardiovascular problems, infertility, prostate enlargement, gynaecomastia, androgenic alopecia and mood swings.

The long-term health effects are serious and do not disappear once doping stops. Real progress depends on a comprehensive approach: a well-structured training plan, appropriate training loads, diet, sleep and preventing overtraining – not the hormone level in itself.

Symptoms of testosterone deficiency in men who exercise

Testosterone deficiency can be difficult to diagnose, as its symptoms are easily confused with the effects of overtraining or a zł diet. Active men should look out for:

• a marked decline in strength and difficulty in maintaining previous performance levels despite following a similar training programme
• slower gain or loss of muscle mass
• lower exercise tolerance and getting tired more quickly during training
• prolonged recovery after sessions
• reduced libido and sexual dysfunction
• deterioration in mood: irritability, lack of motivation, and sometimes symptoms of depression
• a general feeling of low energy outside of training

If these symptoms persist despite a good training plan and adequate recovery, it is worth considering a hormonal assessment – rather than continuing to increase your training volume or changing your supplementation.

Which hormone tests are worth having?

The diagnosis of testosterone deficiency is based on clinical symptoms and at least two morning measurements total testosterone. In certain situations, the doctor may extend the diagnostic investigation to include:

• free testosterone,
• SHBG,
• LH
• i FSH, as well as other studies depending on the clinical presentation. A comprehensive hormonal assessment can be carried out at Synevo.

Test results should always be interpreted in context: the laboratory’s reference ranges, the patient’s age, general state of health and any reported symptoms. A single value outside the normal range requires confirmation and consideration of symptoms – it is not in itself an indication for treatment. Results should always be discussed with a doctor.

Testosterone is part of the jigsaw, not the whole picture

A man’s hormonal profile is the result of his overall lifestyle: his training plan, diet, sleep quality, stress levels and any medication he is taking – not just the number of sessions per week. A mindful approach to strength training involves monitoring training loads, paying attention to the body’s signals, undergoing regular check-ups and being prepared to adjust the plan before permanent hormonal imbalances and a long-term decline in fitness set in.

Summary

Testosterone is a key component in the process of building strength and muscle mass – but it is just one of many. Normal levels of the hormone support protein synthesis and recovery, but they are no substitute for a solid training plan, a proper diet and sufficient sleep. Artificially elevated testosterone levels do not speed up progress – but they do seriously harm your health. If, despite training hard, your results have plateaued, rather than simply increasing the volume of your training, it is worth checking first whether hormonal imbalances might be the cause. Diagnosis is an investment in informed, long-term progress.

Bibliography

• Brunsden, T. J. (2022). A review of the literature: Hormonal responses to resistance training and its effects on strength adaptations. European Journal of Sports & Exercise Science, 10(6).
• Hackney, A. C. (2020). Hypogonadism in exercising males: Dysfunction or adaptive-regulatory adjustment? Frontiers in Endocrinology, 11, 11.
• Tu, Q., Li, G., & Wang, S. (2026). The effect of acute exercise on the dynamics of testosterone levels: A systematic review of randomised controlled trials. PeerJ, 14, e20615.

Important: The contents of this article are solely informational and educational and do not constitute professional medical advice. If you have a serious medical condition or health problem, consult your doctor before you start exercising. The use of the information contained in the article is at the user's own risk.

Publication: Just GYM | Update: 29 June 2026.