Resistance Training

Introduction

Resistance training, (often referred to as “weight training”) describes any form of exercise which involves pulling or lifting against resistance – for example, using kettlebells, elastic bands or dumbbells. Resistance training is often carried out with the goal of improving muscle strength, toning the body and improving muscle endurance. Given the statistics shown on the Background Information page, we can see why resistance training is considered such an important part of adult exercise that the American College of Sports Medicine has had it included in its recommendations since 1988; claiming it should be an “integral part of an adult fitness programme”1

Altering the weight, as well as the number of sets and repetitions can help the progression of resistance training programmes. Resistance training involves causing microscopic tears to muscle fibres (known as muscle fibre catabolism), which are then repaired by the body – this results in muscle regeneration. The repair of these muscle fibres is known as muscle fibre anabolism. An appropriately challenging resistance training session should result in muscle fatigue; which will ensure that muscle repair takes place over repeated resistance training sessions.

What are the benefits of resistance training?

The American College of Sports Medicine widely encourages resistance training as a form of exercise in order to improve strength, muscular endurance and the maintenance of fat-free mass1. Studies have shown that with early intervention, resistance exercise (whether combined with aerobic exercise or not) can play an influential role in lowering the risk of developing obesity2. In general, people who are physically active have a reduced osteoporosis, fracture and general bone deterioration risk; resistance training also plays a significant role in the reduction of the risk of musculoskeletal injuries brought on by muscle imbalance3.

How can resistance training help obesity?

A common concern with a large amount of weight loss to combat obesity is how to reverse any bone or muscle reduction caused; a study by Villareal et al.found that resistance training, when combined with controlled weight loss, can be particularly effective in promoting an improvement in the functional status of obese older adults4. The study looked into the effects of different exercise programmes (aerobic, resistance, or combined aerobic and resistance) when used alongside a weight-management program. Drastic weight loss can often result in muscle reduction as well as bone reduction; carrying out regular resistance exercise can help maintain and build muscle strength, preventing the frailty that could otherwise occur.

 

https://lh6.googleusercontent.com/pECr5eGF2vOSWNDVZjiFGEZCJwI1oFL-V8W2cEZ9qocyhjNNtejwTeODkXPVuYftDIVA45-HF4mRzWo53gWmtS35n1-6DX-By7CtV6mblOvSgb8sBGbT2excHL4PN7B2zvevrFc9

Figure 14: Mean Percent Changes in Body Weight during the Interventions

Percent changes are presented as least-squares–adjusted means; I bars indicate standard errors

 

As shown in the above figure, all types of intervention resulted in a negative weight change – including resistance training. All interventions showed a decrease within the first two weeks; the limitation of this study, however, is that the research only looked into obese adults over the age of 65 – this could have been improved upon by investigating a broader range of ages. With 1 in 5 children in Year 6 classed as obese and 26% of adults classed as obese in 2016 in the UK5, a more inclusive study could potentially produce results that are applicable to a wider audience, as resistance training could have a different effect on various age groups.

A study by Sarsan et al.looked into the effects of aerobic and resistance exercise on obese women; the study randomly assigned obese women to either progressive aerobic or resistance training, without an energy-restricting diet. Both types of exercise resulted in an improved exercise capacity in comparison to the control group, who did no exercise6. While the endurance training group showed improvements in depressive symptoms and VO2max, muscle strength was maintained and improved with resistance training; suggesting that both types of exercise combined would give the most beneficial overall effect.

In another randomised control trial, overweight men were separated into either a control group, a diet-only group, an aerobic training or a combined aerobic and resistance training group. All three intervention groups showed a significant and similar weight loss after twelve weeks; resulting in a loss of 69%, 78% and 97% respectively7. The data indicated that combining aerobic and resistance exercise alongside a dietary regimen can help to prevent the decline in fat-free mass and muscle strength induced by a large amount of weight loss, in comparison to a dietary regimen alone. Again, using these results we can argue that resistance training is best used in conjunction with aerobic endurance training.

 

Conclusion

From the above studies, we can conclude that while endurance training is very beneficial to weight loss, resistance training is particularly important for obese persons during a weight loss programme in order to maintain muscle and bone strength. However, as mentioned on the Background Information page, the use of a person’s Body Mass Index (BMI) to determine the level of obesity could prove detrimental, as resistance training will result in an increase in lean mass. Therefore, using height and weight to then calculate BMI could mean that someone who has gained muscle mass due to resistance training can incorrectly fall into the overweight or obese categories. Regular and effective resistance training can help build and maintain muscle, making a large amount of weight loss less detrimental to muscular strength. This type of training will be most beneficial overall to those who use it in conjunction with endurance training, and also take part in High Intensity Interval Training to boost body fat loss.

 

 

 

(910 words)

References

  1. American College of Sports Medicine 1998: Position Stand “The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults” Medicine and Science in Sports and Exercise. 30:975–991, 1998. http://www.mhhe.com/hper/nutrition/williams/student/appendix_i.pdf
  2. Lee, D., Lavie, C., Sui, X., Blair, S. 2018: 27 March 2018 Circulation. 2018;135:AP299. https://www.ahajournals.org/doi/abs/10.1161/circ.135.suppl_1.p299
  3. Hoffman, J. Resistance Training and Injury Prevention. Indianapolis, IN: American College of Sports Medicine; 2017. https://www.acsm.org/docs/default-source/files-for-resource-library/smb-resistance-training-and-injury-prevention.pdf?sfvrsn=cf409789_2
  4. Villareal, D. T., Aguirre, L., Gurney, A. B., Waters, D. L., Sinacore, D. R., Colombo, E., Armamento-Villareal, R., … Qualls, C. (2017). Aerobic or Resistance Exercise, or Both, in Dieting Obese Older Adults. The New England journal of medicine,376(20), 1943-1955. https://www.acsm.org/docs/default-source/files-for-resource-library/smb-resistance-training-and-injury-prevention.pdf?sfvrsn=cf409789_2
  5. NHS England Digital, Statistics on Obesity, Physical Activity and Diet – England, 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552187/
  6. Sarsan et al. 2017: The effects of aerobic and resistance exercise in obese women, Clinical Rehabilitation, Vol 20 Issue 9 pp 733-782, September 2006. https://files.digital.nhs.uk/publication/0/0/obes-phys-acti-diet-eng-2018-rep.pdf
  7. W. J. Kraemer, J. S. Volek, and J. S. Volek, “Influence of exercise training on physiological and performance changes with weight loss in men,” Medicine and Science in Sports and Exercise, vol. 31, no. 9, pp. 1320–1329, 1999. https://doi.org/10.1097%2f00005768-199909000-00014 https://doi.org/10.1177%2F0269215506070795
Print Friendly, PDF & Email