WHAT IS RESISTANCE TRAINING?
THE BENEFITS
COPD is usually diagnosed in people aged over 40. As we age muscle is lost and this form of training helps preserve muscles which improves mobility and strength, helping with these daily activities.[3]
High-intensity levels of exercise (HIIT) are usually expected to improve general health, however severe COPD patients struggle with HIIT due to dyspnoea (intolerable breathlessness) and peripheral muscle discomfort. Therefore, patients cannot sustain this form of training over long periods of time and so, the physiological results are difficult to determine.[4]
RT allows patients to withstand a high workload whilst being a practical option. This is achieved by progressively training patients to sustain a higher intensity of exercise by cumulatively extending the duration of training over time which reduces dyspnoea (difficulty in breathing.) [5]
HOW CAN IT HELP?
An element of RT is implemented into pulmonary rehabilitation- an educational programme including exercises, managed by physiotherapists, for patients with severe COPD. As the disease progresses with increasing severity, patients often experience intense peripheral muscle deconditioning and the discomfort caused by this is the most common reason why COPD patients struggle with daily activities.[6]
Limb muscles are usually affected in these patients which may also determine the levels of physical activity and is caused by poor nutrition, sedentarity and medication (i.e. corticosteroids.)[8][9]Limb muscle dysfunction in COPD can be identified by signs such as muscle atrophy, reduced strength and a change in fiber type from type I to type II. [10]
Skeletal muscle dysfunction is also a secondary consequence of COPD seen within patients and is characterised by a reduced proportion of type I fibers and atrophy of both type I and II fibers.[11]The addition of RT into the rehabilitation programme significantly increases muscle strength by encouraging muscle fiber hypertrophy.[12]The increase in muscle fiber structure causes formation of more actin and myosin ( the protein filaments of muscles) which allows a greater force to be exerted during RT. [13] As a result, this has a positive impact on the exercise tolerance of these patients.[14]
WHERE IS THE EVIDENCE?
Many studies have taken place to research the benefits of different forms of exercise on COPD.
A systematic review published in 2009 consisted of 18 controlled trials, mainly of patients diagnosed with severe COPD. In these trials, participants had two to three sessions of training for 12 weeks on average. In these sessions, they had five resistance exercises and for each muscle group, they were required to train two to four sets of eight to 12 repetitions. The repetitions started at a 30% intensity and progressively increased to 90% of their one-repetition maximum (the maximum weight that can be lifted by an individual in a single repetition.)[15]After completion of this programme, participants were found to have a significant increase in muscle strength concluding that short-term progressive RT was extremely beneficial to COPD patients.
A meta-analysis of this study showed an increase of 25% in maximum knee extensor muscle strength after the progressive RT compared to a 10% increase shown by aerobic training alone or 0% increase after no intervention.[16]
In two of these trials there was a reduction in total fat percentage and an increase in total lean mass after the course of 12 weeks. [17][18]
This evidence suggests that progressive resistance exercise has the ability to increase muscle strength in COPD patients which allows them to perform better on a daily basis giving them a better quality of life and enabling them to carry out a healthier, active lifestyle rather than a sedentary one.
RESISTANCE vs ENDURANCE
In pulmonary rehabilitation, the purpose of endurance exercises is to improve lung function however strength training is specifically designed for muscle growth.[19]Studies show that there is a higher increase in muscle strength after RT than there is after endurance/aerobic training alone .[20] As seen in Figure 1, combining aerobic and strength training resulted in a significantly greater increase in percentage change, especially in thigh muscle cross-sectional area (MCSA) and pectoralis major strength
![[1]](https://i1.wp.com/elitetrack.com/wp-content/uploads/2014/08/strength-training-getting-started.jpg?fit=470%2C265&ssl=1){kind=link}
PROBLEMS
Although RT may have a beneficial affect on peripheral muscles, it can have an adverse effect on patients with musculoskeletal disorders or osteoporosis as it can increase the risk of bone fractures and other injuries. [21] This is often seen due to misuse of RT machinery or lack of experience with this form of training as patients strain themselves and increase their workload beyond their one repetition maximum. It is therefore recommended that each patient’s condition is assessed individually so that they are given the correct advice.
CONCLUSION
Mean difference in health-related quality of life before and after training
RT plays an important role in muscle growth of COPD patients who primarily suffer from muscle atrophy. It may be favoured due to less dyspnoea seen in patients during exercise in comparison to endurance training which makes it more tolerable for patients.[22]The wider range of strength training activities helps maintain interest of patients which motivates them to improve their skills. As a result, patient attendance to these programmes increases which contributes towards better general health.[23]However, it is evident that combining strength and aerobic training helps maximise results. Therefore, each individual should be provided with a customised pulmonary rehabilitation programme which enables the use of both strategies safely and efficiently.
References
[1]https://i1.wp.com/elitetrack.com/wp-content/uploads/2014/08/strength-training-getting-started.jpg?fit=470%2C265&ssl=1
[2]http://exercise.trekeducation.org/resistance-training/what-is-resistance-training/
[3]https://statistics.blf.org.uk/copd
[4]Maltais F, LeBlanc P, Jobin J, et al. Intensity of training and physiologic adaptation in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1997; 155: 555–561
[5]http://erj.ersjournals.com/content/38/4/971
[6]Nici L, Donner C, Wouters E, et al. American Thoracic Society/ European Respiratory Society statement on pulmonary rehabilita- tion. Am J Respir Crit Care Med 2006; 173: 1390–1413
[7]https://helenhayeshospital.org/pulmonary-rehabilitation/
[8]https://www.ncbi.nlm.nih.gov/pubmed/25438125
[9]Barreiro E, Respiratory Gea J. Limb muscle dysfunction in COPD. COPD. 2015;12:413-26
[10]MaltaisF,DecramerM,CasaburiR,etal.AnofficialAmericanThoracic Society/European Respiratory Society statement: update on limb muscle dysfunction in chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2014;189(9):e15–e62
[11]Swallow EB, Reyes D, Hopkinson NS, Man WD, Porcher R, Cetti EJ, et al. Quadriceps strength predicts mortality in patients with moderate to severe chronic obstructive pulmonary disease. Thorax 2007;62(2):115-120
[12]https://www.researchgate.net/publication/40029146_Resistance_exercise_and_nutrition_to_counteract_muscle_wasting
[13]https://www.scientificamerican.com/article/how-does-exercise-make-yo/
[14]Nici L, Donner C, Wouters E, et al. American Thoracic Society/ European Respiratory Society statement on pulmonary rehabilita- tion. Am J Respir Crit Care Med 2006; 173: 1390–1413
[15]https://support.polar.com/uk-en/support/one_repetition_maximum_1rm
[16]O’Shea SD, Taylor NF, Paratz JD. Progressive resistance exercise improves muscle strength and may improve elements of perfor- mance of daily activities for people with COPD: a systematic review. Chest 2009; 136: 1269–1283
[17]Casaburi R, Bhasin S, Cosentino L, et al. Effects of testosterone and resistance training in males with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2004; 170: 870–878
[18]https://www.sciencedirect.com/science/article/pii/S0422763816300851
[19]https://www.atsjournals.org/doi/full/10.1164/ajrccm.159.3.9807034#readcube-epdf
[20]O’Shea SD, Taylor NF, Paratz JD. Progressive resistance exercise improves muscle strength and may improve elements of perfor- mance of daily activities for people with COPD: a systematic review. Chest 2009; 136: 1269–1283
[21]https://www.atsjournals.org/doi/full/10.1164/ajrccm.159.3.9807034#readcube-epdf
[22]Ortega F, Toral J, Cejudo P, Villagomez R, Sa ́nchez H, Castillo J, Montemayor T. Comparison of effects of strength and endurance training in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2002;166(5):669-674
[23]Simpson, K., K. Killian, N. McCartney, D. G. Stubbing, and N. L. Jones.1992. Randomised controlled trial of weightlifting exercise in patients with chronic airflow limitation. Thorax 47:70–75
[i]https://www.atsjournals.org/doi/full/10.1164/ajrccm.159.3.9807034#readcube-epdf
[ii]https://www.atsjournals.org/doi/full/10.1164/ajrccm.159.3.9807034#readcube-epdf
