The Endless Debate: Strength Training vs. Endurance Training
The topic of fitness and sports has gained enormous importance in recent years. Whether for aesthetic, health, or performance reasons – more and more people are looking for the optimal form of training for them. In this context, two types of training play a central role: strength training and endurance training. Men, in particular, are often interested in which form of training is better suited to help them achieve their fitness goals. Is it lifting weights or endurance running? And how do these two types of training affect the body, especially in terms of testosterone, the most important male sex hormone?
Testosterone significantly influences muscle mass, fat burning, and overall physical performance. However, the effects of strength and endurance training on testosterone can vary greatly.
In this article, we take a closer look at what strength training and endurance training actually are, what forms exist, and how they affect the male body, especially testosterone levels. We will also address the differences between the sexes and examine whether there really is a "better" form of training for men.
What is strength training?
Strength training, also known as resistance training, is a form of training in which the body works against external resistance. The goal of strength training is to increase muscle strength and mass. Resistance can come in the form of dumbbells, machines, one's own body weight, or other training equipment. There are different forms of strength training, each pursuing different goals and targeting different muscle groups:
• Free weight training: This includes lifting dumbbells, barbells, or kettlebells. It requires stability and control of the body.
• Machine training: Machines are used here that restrict the range of motion and thus target the training effect at specific muscles.
• Bodyweight training: Here, one's own body weight is used to create resistance. Push-ups, squats, and pull-ups are classic exercises of this type.
• Functional training: This type of training aims to imitate everyday movements and increase the functionality of the body. This can be done with or without additional weight.
Strength training is of particular interest to men, as it not only increases muscle mass but can also have a positive effect on testosterone levels. Studies have shown that intense strength training, especially that involving heavy weights and complex movements, leads to an increase in testosterone levels (Craig et al., 1989). However, strength training does not only have effects on testosterone. It strengthens the cardiovascular system, promotes bone density, and has positive effects on metabolism (Miko et al., 2020).
What is endurance training?
Endurance training, also known as cardiovascular training, includes all types of training aimed at increasing the body's endurance. It promotes the performance of the cardiovascular system and improves the ability to perform physical exertion over longer periods. Typical forms of endurance training are:
• Running: Jogging and running are classic endurance exercises that can be performed both outdoors and on a treadmill.
• Cycling: Whether on a stationary bike or on a bike ride, cycling is a joint-friendly method to build endurance.
• Swimming: Swimming offers a full-body workout and is particularly joint-friendly.
• Rowing: Rowing on a rowing machine or in the water trains not only endurance but also the back muscles.
• HIIT (High Intensity Interval Training): This form of training combines high-intensity exercise phases with short rest periods and is becoming increasingly popular for promoting both endurance and strength.
In contrast to strength training, endurance training is not primarily aimed at building muscle mass. Rather, the focus is on improving aerobic capacity and fat burning. But here too, research shows that endurance training has positive effects on health, strengthens the cardiovascular system, and can reduce stress (Marmat et al., 2020).
Advantages and disadvantages of strength and endurance training
Advantages of strength training
1. Muscle building
Strength training is the most effective method for building muscle mass, as it applies targeted stimuli that stimulate muscle fibers to grow. More muscle mass means a higher basal metabolic rate, even at rest, because muscles burn more calories than fat. This is beneficial not only for body composition but also for long-term weight control and overall health (Beneke R., 1998).
2. Strengthening the skeletal system
Regular strength training increases bone density, as mechanical loading stimulates bone formation. Especially in old age, when the risk of osteoporosis increases, strength training has a preventive effect. Studies show that even older people can improve their bone strength and thus their mobility through moderate strength training (O'Bryan et al., 2022).
3. Testosterone increase
Intense strength training, especially with heavy weights and low repetitions, leads to a short-term increase in testosterone levels (Craig et al., 1989). Testosterone is crucial for muscle building, recovery, and overall vitality. A long-term higher level promotes physical performance and reduces age-related declines (Harvard Health, 2023).
4. Improved posture and functionality
Functional strength training not only strengthens the muscles but also the stability and balance of the body (Xiao et al., 2023). This leads to better posture and reduces the risk of back problems. Exercises such as deadlifts or planks train multiple muscle groups simultaneously, which has a positive effect on everyday movement patterns.
Disadvantages of strength training
1. Increased risk of injury
Poor technique or weights that are too heavy can lead to injuries such as muscle strains or joint problems. Without professional guidance or a proper warm-up phase, this risk increases significantly. Beginners, in particular, often underestimate the importance of proper execution.
2. Higher demands on technique and equipment
Effective strength training requires a certain level of technical know-how to perform exercises correctly and target muscle groups specifically. In addition, equipment such as dumbbells, machines, or even a gym is often necessary, which can mean an investment of time and money.
Advantages of endurance training
1. Improvement of cardiovascular health
Regular endurance training strengthens the heart, improves circulation, and lowers blood pressure. This significantly reduces the risk of cardiovascular diseases such as heart attack or stroke (Marmat et al., 2020). A stronger heart works more efficiently, which is also noticeable in everyday life, e.g., through more energy and less fatigue.
2. Increase in endurance
Endurance training trains the body's ability to efficiently provide energy over longer periods. This increases overall performance, whether in sports, at work, or in everyday life (Morat et al., 2017). Those who exercise regularly notice that climbing stairs, long walks, or physically demanding tasks become significantly easier.
3. Stress reduction
Endurance training leads to the release of endorphins, the so-called happiness hormones. This helps to reduce stress, improve mood, and promote mental health. Studies have shown that people who regularly run, cycle, or swim are less susceptible to depression and anxiety disorders (da Costa et al., 2022).
4. Fat burning
During endurance training, the body uses stored fat reserves, especially at moderate intensities. This makes it an excellent method for weight management. In addition, it improves insulin sensitivity, which stimulates metabolism in the long term and reduces the risk of type 2 diabetes (Orlando et al., 2016).
Disadvantages of endurance training
1. Muscle loss in case of overtraining
In case of too intense or prolonged endurance training, the body may begin to use muscle mass as an energy source. This is because increased cortisol, a stress hormone, promotes catabolic processes. In the long term, this can lead to a leaner but less muscular body, which is undesirable for many men.
2. Strain on joints and overuse injuries
Especially in sports such as running or intense cycling, joints, tendons, and muscles can become overloaded. Without sufficient recovery, overuse injuries such as shin splints, Achilles tendonitis, or knee problems can develop. A varied training routine and proper technique are essential here.
With this detailed explanation, the advantages and disadvantages are not only better understood but also presented more comprehensively.
Differences between men and women
Although the advantages and disadvantages of strength and endurance training are largely the same, there are differences between men and women in terms of the body's reactions to these forms of training. Due to their higher testosterone levels, men generally have more potential to build muscle mass, while women tend to respond better to endurance training, as their physical makeup allows for greater fat burning.
However, this does not mean that men cannot benefit from endurance training, or that women cannot make progress in strength training. Every person, regardless of gender, can benefit from the respective advantages of a combination of both forms of training.
The connection with testosterone
How testosterone affects the body
Testosterone is the primary male sex hormone and plays a central role in many physiological processes (Roney & Gettler, 2015). It is particularly important for the development and maintenance of muscle mass. A high testosterone level is associated with a reduced body fat percentage and improved fat utilization (Kelly & Jones, 2015). Testosterone also influences mood and energy levels, which is why men with higher testosterone levels are often perceived as more motivated and energetic.
During strength training, the body is subjected to high stress that strains the muscle fibers and creates micro-tears. This process initiates a healing and adaptation process, in which the body repairs the damaged muscle fibers and makes them stronger. The hormonal increase in testosterone supports this process by promoting muscle building and accelerating recovery. Studies show that both intense strength training and periods of maximal exertion (e.g., sets with few repetitions and heavy weights) stimulate the production of testosterone (Kvorning et al., 2006).
How testosterone levels affect training performance
It is no secret that a higher testosterone level leads to better training performance. Men with higher testosterone levels can generally lift more weight, recover faster, and have overall higher performance in strength training. In contrast, a testosterone deficiency can lead to muscle loss, lower energy, and poorer performance.
There are many scientific studies showing that testosterone levels influence the ability to handle intense training stress. Men with higher testosterone levels are able to perform more intense strength exercises, which leads to better muscle adaptation to the stress and faster muscle growth (Bhasin et al., 1996), (Kraemer et al., 2004).
Another interesting aspect is that testosterone plays a role not only during training but also in the recovery phase after the workout. Studies show that testosterone has a direct effect on protein biosynthesis, which is crucial for muscle building. A sufficient increase in testosterone levels after training helps to efficiently repair and build muscle tissue (Howard et al., 2022).
The effect of strength training on testosterone
Testosterone plays a crucial role in a man's body. It influences not only the development of male sex characteristics but also muscle development, fat distribution, and overall vitality. The testosterone level varies over a man's life, decreasing in most cases with increasing age. But how does strength training specifically affect testosterone levels?
Several studies have shown that intense strength training can significantly increase testosterone levels. Especially with heavy weights and short, intense sets (e.g., with 3-6 repetitions), an increase in testosterone after training was observed (Kraemer et al., 1999). It is assumed that the body tries to recover from the stress in this way and promote muscle building, which is accompanied by an increase in testosterone.
However, the testosterone increase after strength training is only temporary and can drop again after a certain period. The long-term effects on testosterone levels depend on the frequency and intensity of training. However, long-term strength training can lead to a stabilization or even an increase in testosterone levels in the long term.
The effect of endurance training on testosterone
In contrast to strength training, endurance training has a rather ambivalent effect on testosterone levels. While moderate endurance training such as running or cycling may slightly increase testosterone levels, excessive endurance training, especially in the form of long, intense exertion, can lead to a drop in testosterone.
Studies, such as those by Hackney et al. (1988), have shown that endurance athletes tend to have lower testosterone levels than strength athletes. This could be due to the high stress on the body, which leads to an increase in cortisol during long endurance training, a stress-inducing hormone that can negatively affect testosterone levels.
The role of cortisol in endurance training
A crucial factor as to why excessive endurance training can negatively affect testosterone levels is the hormone cortisol. Cortisol is known as a stress hormone and is produced by the body during times of high stress or exertion. Too long or too intense endurance sessions increase cortisol levels, which in turn can negatively affect testosterone levels. This connection was demonstrated in a study by Maimoun et al. (2003).
While moderate endurance training such as light running or cycling does not significantly increase cortisol levels, intense training, as is common among marathon runners or elite athletes, can lead to chronically high cortisol levels. Elevated cortisol levels over extended periods can suppress testosterone levels, which can have negative long-term effects on muscle mass and fat metabolism.
Endurance Training and Fat Burning
However, a positive effect of endurance training is the body's increased ability to burn fat. It is generally believed that endurance training promotes fat burning, as the body uses fat as an energy source for longer periods. This could also be beneficial for testosterone, as a lower body fat percentage is associated with higher testosterone levels. Studies show that men with lower body fat percentages tend to have higher testosterone levels (Ma et al., 2024).
However, the question of whether endurance training or strength training leads to higher testosterone levels in the long term is complex and depends on many individual factors. It could even be argued that a combination of both—moderate endurance training for fat burning and strength training to increase muscle mass and testosterone—yields the best results.
How Strength Training and Endurance Training Can Work Together
Many men who want to increase both their endurance and muscle mass wonder whether it is possible to train both at the same time. In fact, recent scientific studies show that a combination of strength and endurance training is not only possible but also beneficial, provided certain basic principles are followed.
Timing and Order of Workouts
There are various approaches to combining strength and endurance training. One of the most important considerations is the order of the workouts. One often-recommended strategy is to perform strength training before endurance training. This is because intense endurance workouts can fatigue the muscles, impairing performance in the subsequent strength training. Therefore, if you want to train both endurance and strength in a single workout, it makes sense to start with strength training when your energy levels are at their highest.
Periodization and Variation
Another way to effectively combine strength and endurance training is through periodization. This involves alternating phases of intense strength training with phases of intense endurance training. This method has proven particularly effective for increasing muscle mass and improving endurance without neglecting either goal. Such a training plan provides variety and prevents the body from adapting to a single training stimulus, which delivers better results in the long term.
Combining Training Methods for Greater Success
For many men who want to build strength and improve their endurance, a combination of both types of training is often the best approach. Studies have shown that men who perform a mix of strength and endurance training achieve overall better results in terms of body composition, muscle maintenance, and general fitness.
A good training plan could look like this, for example:
• Monday: Strength training (legs and back)
• Tuesday: Endurance training (light running or cycling)
• Wednesday: Strength training (upper body and arms)
• Thursday: Active recovery (light endurance activities such as swimming or yoga)
• Friday: Combination of strength and endurance training (interval training or circuit training)
Differences in the Effects of Strength Training and Endurance Training on Men and Women
Although both men and women benefit from strength and endurance training, there are gender-specific differences that are worth considering. The influence of testosterone on muscle building and fat burning plays a particularly important role here.
Male Physiology: Higher Testosterone Levels and Muscle Building
Men generally have significantly higher testosterone levels than women, which helps them achieve faster progress in muscle building and strength training. Higher testosterone not only promotes muscle building but also contributes to fat burning. Men can build muscle mass more quickly with strength training and often have a higher basal metabolic rate, which gives them an advantage in burning fat.
Female Physiology: Lower Testosterone and a Different Training Response
Compared to men, women have significantly lower testosterone levels, which means they generally build less muscle mass (Ikehata et al., 2023). However, this does not mean that women cannot be successful with strength training—they simply have a different physiological response to training. Women can increase their muscle strength and reduce their body fat percentage through strength training, but muscle growth is generally not as pronounced as in men.
Women generally respond better to endurance training, especially when it comes to improving aerobic capacity and burning fat. Female endurance athletes tend to have lower body fat levels and can benefit particularly from moderate endurance training.
Case Study: How Jonas Found the Right Training Strategy for His Body
Jonas is 36 years old, works as an IT project manager, and generally leads an active life. For years, he made sure to get enough exercise, mainly through regular running sessions. Two to three times a week after work, he went jogging, also participated in half marathons, and was proud of his athletic endurance performance.
Despite this, Jonas felt like he was making no progress physically. His energy levels fluctuated, his body definition was minimal, and even after extended periods of cardio, his weight or body fat percentage barely changed. He also noticed a gradual decline in his motivation to train, libido, and sexual desire. At first, he blamed it on work stress, but eventually he realized: There had to be more to it.
A comprehensive medical check-up revealed that his testosterone level was 11.8 nanomoles per liter, below the age-appropriate average. The medical assessment was functional testosterone deficiency. Although the level was not in the clinically critical range, it showed clear symptoms—typical for men who do a lot of endurance training but hardly any resistance training.
The Training Shift: Combination Instead of One-Sidedness
After a detailed consultation, Jonas decided to start an individually tailored testosterone replacement therapy, accompanied by regular monitoring. At the same time, his training plan was redesigned. His focus shifted from pure endurance training to a well-thought-out combination with strength training to more effectively support and increase his hormone production in the long term.
Twice a week, he now performed intense strength training with compound exercises such as squats, deadlifts, and bench presses. In addition, he incorporated circuit training to improve strength endurance. Long running sessions were replaced by one or two moderate cardio sessions per week. His new training program was structured, varied, and designed to support his hormonal balance.
His daily life also changed. Jonas paid more attention to his diet: More protein, healthy fats, high-fiber foods, and natural sources of important micronutrients such as vitamin D, zinc, and magnesium. This form of nutrition can have a positive effect on testosterone production. He cut out sugar, alcohol, and highly processed products, which improved not only his hormone levels but also his overall fitness.
Sleep became a priority. Jonas managed to stabilize his sleep rhythm and sleep at least seven hours a night. Less screen time in the evening, relaxation exercises, and a consistent daily routine meant he woke up feeling more rested—an important factor for naturally increasing his testosterone levels.
Stress management was another key point. Chronic stress increases cortisol levels, which inhibits testosterone production. Through conscious breathing, regular breaks, and physical activity during the day, Jonas managed to significantly reduce his stress levels. This allowed him to actively improve another influencing factor on his hormone levels.
The Results After Three Months
Jonas’s body began to change visibly. More muscle growth, reduced body fat, and more defined contours. He felt stronger, mentally more stable, and sexually more active. His libido had returned, his self-confidence increased, and he also showed a noticeable boost in training performance.
A repeat blood test confirmed the subjective impression: His testosterone level was now stably in the upper normal range. His hormonal situation had improved—both through medical support and lifestyle factors such as targeted training, conscious nutrition, restful sleep, and less stress. His overall fitness benefited from this holistic approach.
“I never would have thought that too much endurance training had damaged my hormone balance. It was only the combination of strength training, therapy, and conscious nutrition that turned things around for me. And the best part: I feel like myself again.”
Why Jonas’s Journey Is a Wake-Up Call for Many Men
Jonas is not an isolated case. Many men over 30 or 40 rely solely on endurance training to burn fat and stay healthy, but neglect the central role of testosterone, resistance training, and hormonal balance. A testosterone level that is too low affects not only muscle building but also energy, mood, sleep, libido, and sexual performance.
Balanced strength training combined with targeted nutrition, proper recovery, and sensible medical support can increase the production of this important hormone—long-term and effectively. Those who recognize the signs early can not only optimize their testosterone levels through targeted measures but also significantly improve their overall quality of life.
Regular monitoring of free testosterone, not just total testosterone, is also essential. This is the only way to see how much biologically active hormone is actually available to the body.
Tips for Men Who Want to Naturally Increase Their Testosterone Production
Many of these steps can be easily integrated into daily life:
- Combine targeted strength training with moderate endurance training
- Make sure you get restful sleep, at least seven to eight hours a day
- Actively reduce stress to keep cortisol levels low
- Eat nutrient-rich foods: Zinc, magnesium, vitamin D, omega-3 fatty acids
- Maintain a healthy body weight; being overweight lowers testosterone levels
- Avoid nicotine and excessive alcohol consumption
- Maintain regular exercise, sex, and conscious relaxation
Conclusion: Those who take their hormonal health seriously are not only investing in muscle mass or appearance, but also in joy of life, vitality, libido, sleep quality, and long-term fitness. The balance of hormone levels is crucial to how we feel in our own bodies—physically, sexually, and mentally. Men who learn to listen to their body’s signals and take targeted action sustainably and naturally improve their well-being.
Conclusion: Strength Training and Endurance Training as the Optimal Combination for Men
The question of which type of training is better for men—strength training or endurance training—cannot be answered with a one-size-fits-all approach. Both types of training have their specific benefits and support each other when combined in a balanced training plan.
For men who want to build muscle mass and optimize their testosterone levels, strength training is key. Those who also want to improve their endurance or reduce their body fat percentage should incorporate endurance training into their plan. The combination of both offers the best results and ensures a holistic improvement in physical fitness.
Testosterone plays a central role here: strength training promotes an increase in testosterone, while endurance training can help reduce body fat, which also leads to higher testosterone levels. It is important to find the right balance and an individual training approach to be successful in the long term.
