Hormones and Rest-Pause Training

Resistance training is a cornerstone of fitness regimes, particularly for those aiming to build muscle strength and hypertrophy. Recent studies have shed light on the significant hormonal responses elicited by various resistance training exercises, providing valuable insights for us as personal trainers. Moreover, innovative training techniques like rest-pause have been shown to enhance muscle growth and strength gains. This article delves into the science behind these methods and offers practical advice on how to optimise training programmes to maximise hormonal and performance adaptations.

The Hormonal Impact of Resistance Training

Resistance training exercises, such as the bench press and leg press, have been shown to significantly influence hormonal responses. Hormones like testosterone and cortisol play crucial roles in muscle growth, recovery, and overall performance. Understanding how different exercises affect these hormones can help us design more effective workout programmes.

Testosterone and Cortisol Responses

A recent study investigated the effects of single sessions of bench press versus leg press on hormonal responses in strength-trained males. The study found that both exercises led to significant increases in testosterone levels immediately post-exercise. However, there were notable differences in cortisol responses. Cortisol, often referred to as the stress hormone, was significantly lower post-exercise in the bench press condition compared to the leg press. This suggests that the bench press might induce less systemic stress while still promoting an anabolic environment conducive to muscle growth (MDPI).

These findings highlight the importance of exercise selection based on the desired hormonal response. Incorporating exercises like the bench press can help manage cortisol levels, potentially leading to better recovery and less muscle breakdown. Conversely, exercises that engage larger muscle groups, such as the leg press, might be used strategically to capitalise on their robust testosterone response, promoting greater muscle hypertrophy.

Rest-Pause Training Techniques

Rest-pause training is an advanced technique that involves performing a set of repetitions to failure, taking a short rest, and then performing additional repetitions. This method has been shown to be particularly effective in increasing muscle strength and hypertrophy compared to traditional resistance training.

Here’s how to implement rest-pause training:

Perform a set using your usual 6-10 repetition weight, then set the weight down.
Take 15 seconds of deep breaths, then pick the weight back up and continue to lift to failure.
Repeat step two as many times as desired, typically twice.

Benefits of Rest-Pause Training

A study comparing rest-pause training to traditional resistance training found that the rest-pause method led to greater increases in muscle strength and hypertrophy. Participants in the rest-pause group showed significant improvements in insulin-like growth factor-1 (IGF-1) levels and a favourable ratio of follistatin to myostatin, markers that are critical for muscle growth. Additionally, the rest-pause group exhibited greater increases in muscle cross-sectional area and strength gains in exercises like the bench press (MDPI).

These results suggest that rest-pause training can be a highly effective tool when we are looking to maximise our clients’ muscle growth and strength gains. The technique’s ability to push muscles beyond their typical limits with brief recovery periods can stimulate greater muscle adaptation and growth.

Male/Female Differences

Male and female differences in response to resistance training, particularly regarding hormonal responses and training techniques like rest-pause, are significant. Generally, men tend to experience greater increases in testosterone levels post-exercise compared to women, due to higher baseline levels of this hormone. This difference can influence the rate and extent of muscle hypertrophy and strength gains. However, women can still achieve substantial muscle growth and strength improvements through resistance training, albeit through slightly different mechanisms. For instance, women often rely more on increases in growth hormone and insulin-like growth factor-1 (IGF-1) for muscle development. Additionally, the rest-pause technique can be effective for both genders, but we may need to adjust rest periods and volume to cater to the different recovery needs and hormonal profiles of male and female clients.

Understanding these physiological differences helps us create more tailored and effective training programmes for our clients.

Practical Application

Integrating the insights from hormonal response research and rest-pause training techniques can help us design more personalised and effective resistance training programmes. Here are some practical strategies:

Tailoring Training Programmes

Exercise Selection Based on Hormonal Responses:
- Bench Press:Use the bench press to leverage its ability to increase testosterone while managing cortisol levels. This exercise can be particularly beneficial during phases of training focused on muscle hypertrophy and recovery.
- Leg Press:Incorporate the leg press to stimulate significant testosterone responses, especially during strength-building phases. This exercise engages large muscle groups and can be used to maximise anabolic hormonal responses.
Implementing Rest-Pause Training:
- Structure:Incorporate rest-pause sets for key exercises like the bench press. For example, perform a set to failure, rest for 15-20 seconds, and then continue with additional repetitions until failure.
- Frequency:Use rest-pause training 1-2 times per week per muscle group to avoid overtraining and ensure adequate recovery.
- Progression:Gradually increase the weight or the number of rest-pause cycles as the client adapts to the training stimulus.

Monitoring and Adjusting Programmes

Hormonal Monitoring:
- Consider periodically assessing clients’ hormonal responses to track the effectiveness of the training programme. This can be done through blood tests to measure testosterone and cortisol levels.
- Adjust the training programme based on hormonal feedback. For instance, if cortisol levels are consistently high, it might be necessary to incorporate more recovery-focused exercises or adjust the intensity of the workouts.
Feedback and Adaptation:
- Regularly solicit feedback from clients regarding their perceived exertion, recovery, and overall wellbeing. This information can help fine-tune the training programme.
- Be flexible and ready to adjust the programme based on clients’ progress and feedback. This personalised approach can help optimise results and maintain client motivation.

Case Study

Let’s consider a case study of a client named John, a 30-year-old male with intermediate resistance training experience. John’s primary goals are to increase muscle mass and strength while managing stress levels.

Initial Assessment and Programme Design

Hormonal Assessment:
- Initial blood tests reveal that John has moderately high cortisol levels and average testosterone levels. This information suggests that his training programme should include exercises that manage cortisol while promoting testosterone.
Programme Structure:
- Week 1-4: Hypertrophy Phase
  - Bench Press: 3 sets of 8-12 reps, incorporating rest-pause on the final set.
  - Leg Press: 3 sets of 10-15 reps, focusing on higher volume to stimulate testosterone.
  - Accessory Exercises: Incorporate exercises like dumbbell flyes, bent over rows and lunges to balance the workout.
- Week 5-8: Strength Phase
  - Bench Press: 4 sets of 4-6 reps, using rest-pause on the last two sets.
  - Leg Press: 4 sets of 6-8 reps, increasing the weight to focus on maximal strength.
  - Accessory Exercises: Include compound movements like deadlifts and rows to further engage large muscle groups.

Monitoring Progress and Adjustments

Bi-Weekly Check-Ins:
- Assess John’s feedback on his energy levels, recovery, and stress. Make adjustments to the intensity and volume based on his responses.
- Conduct follow-up hormonal assessments at the end of each phase to track changes in testosterone and cortisol levels.
Programme Adjustments:
- If cortisol levels remain high, incorporate more rest and recovery days or reduce the intensity of leg press sessions.
- If testosterone levels increase significantly, consider maintaining the current training intensity while gradually increasing volume to further stimulate hypertrophy.

We can greatly enhance our clients’ training outcomes by understanding the hormonal responses to resistance exercises and incorporating advanced techniques like rest-pause training. By tailoring programmes to individual hormonal profiles and leveraging the benefits of rest-pause sets, we help clients achieve their muscle growth and strength goals more effectively. Regular monitoring and adjustments based on feedback and hormonal assessments ensure that the training remains personalised and optimal for each client’s needs.

References

Kraemer, W. J., Marchitelli, L., Gordon, S. E., Harman, E., Dziados, J. E., Mello, R., … & Fleck, S. J. (1990). Hormonal and growth factor responses to heavy resistance exercise protocols. Journal of Applied Physiology, 69(4), 1442-1450. Click here to review the full research article

Zając, A., Poprzęcki, S., Petr, M., & Baron-Kaczmarek, D. (2024). Acute hormonal and inflammatory responses following lower and upper body resistance exercises performed to volitional failure. International Journal of Molecular Sciences, 25(13), 7455. Click here to review the full research article

Neto, G. R., & Costa, P. B. (2023). Acute hormonal responses to multi-joint resistance exercises with blood flow restriction. Journal of Functional Morphology and Kinesiology, 8(1), 3. Click here to review the full research article

Karimifard, M., Arazi, H., & Mehrabani, J. (2023). Twelve weeks rest-pause and traditional resistance training: Effects on myokines and performance adaptations among recreationally trained men. Stresses, 3(1), 302-315. Click here to review the full research article

West, D. W., & Phillips, S. M. (2012). Anabolic processes in human skeletal muscle: restoring the identities of growth hormone and testosterone. Physiological Reviews, 92(2), 521-553. Click here to review the full research article

Nunes, J. P., Ribeiro, A. S., Schoenfeld, B. J., & Cyrino, E. S. (2020). Resistance training in postmenopausal women: A systematic review. Journal of Strength and Conditioning Research, 34(9), 2466-2476. Click here to review the full research article/

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