NIHR Signal Resistance training may prevent obese older people becoming frail when losing weight

Published on 29 August 2017

Combining resistance training with aerobic exercise increased physical function in older, obese adults who were following a weight loss programme. Functional improvements, such as the speed to stand from a chair or to climb stairs, were greater with combination training (21%) than with either type of exercise performed alone (14%).

This randomised controlled trial assigned 160 obese adults in the USA (aged over 65, mostly educated white females) to the different types of exercise for six months. Those exercising lost about 9% body weight on their diets. Resistance training was most effective for preventing loss of muscle and bone mass. This highlights the importance of strength training in helping to prevent frailty, which is a common problem linked to both obesity and weight loss in older adults.

The study supports current UK government recommendations that older adults perform muscle strengthening exercises on at least two days a week.

Resistance training may prevent obese older people becoming frail when losing weight

Why was this study needed?

Obesity is associated with many health problems including heart disease and stroke. Almost a third of people in the UK are obese, costing the NHS around £6.1 billion a year.

Physical frailty is a natural part of ageing but is associated with increased risk of falls and mortality. Obesity can worsen the effects of frailty, but losing weight may cause loss of muscle and bone mass.

Previous studies showed that aerobic and resistance training combined with weight loss improved physical function but didn’t prevent loss of muscle or bone mass or reverse frailty. Aerobic exercise increases cardiovascular fitness with no effect on strength, while resistance training has the opposite effect. The researchers therefore considered that these opposing physiological effects could interfere with each other.

They aimed to compare the two types of exercise when performed alone with the combination of both on preventing frailty during weight loss in older, obese adults.

What did this study do?

This US-based randomised controlled trial included 160 obese adults (aged 65 or more) with mild to moderate frailty as defined by score 18-31 on the Physical Performance Test (PPT).

Participants were assigned to six months of aerobic exercise, resistance training (each 60 minutes three times weekly) or a combination of both (75-90 minutes three times weekly). All groups completed a weight loss programme, including weekly meetings with a dietician, behavioural therapy, and a diet providing an energy deficit of 500-750kcal per day. A control group received no exercise or weight loss programme.

The main outcome was the difference in PPT scores (a composite scale that ranges from 0 to 32 maximum) from start to end of the trial.

Assessors, but not participants, were unaware of group assignment. Participants were mostly female, white, well-educated and physically able to take part. This may limit applicability.

What did it find?

  • People in the combination group showed the greatest improvement in physical function, with an increase of 5.5 (+0.4) points in Physical Performance Test (PPT) scores at six months. This was a 21% increase from the average PPT score at the start of the trial. The change was more than the 1.8 + 2.5 points the authors considered a clinically important difference between groups.
  • The aerobic and resistance groups showed smaller improvements, with both groups showing an increase of 3.9 (+0.4) points in PPT scores, or 14%, from study start. Functional improvements in all exercise groups were significantly greater than the control group (4% score increase).
  • All exercise groups showed a 9% decrease in body weight (<1% in controls), but the combination and resistance groups lost less lean (non-fat) body mass (-1.7kg or -3% and -1.0kg or -2%, respectively) than the aerobic group (- 2.7kg or -5%).
  • There was minimal change in bone mineral density at the hip in the resistance group (-0.006g/cm2 or <1% decrease), but some loss in the combination group (-0.014 g/cm2 or -1.1%), and greatest loss in the aerobic group (-0.027g/cm2 or -2.6%).

What does current guidance say on this issue?

The British Society of Geriatrics best practice guidance (2014) states that exercise improves mobility and function for older people with frailty. They say that strength and balance training are key components but the best exercise regimen remains uncertain.

Department of Health physical activity guidelines (2011) recommend that older adults (65+) should aim to undertake at least 150 minutes of moderate intensity physical activity a week. They should incorporate physical activity both to improve muscle strength and improve balance and co-ordination on at least two days a week. Muscle strengthening exercises may involve using body weights or working against a resistance.

What are the implications?

This study demonstrates the importance of resistance training alongside aerobic exercise to preserve physical function and reduce frailty in older adults. This is consistent with Department of Health advice on muscle strengthening exercises.

It is worth noting the specific population studied. Also, the trial was only of six months duration, so it’s uncertain how long these improvements could be sustained.  

Other studies have shown that progressive resistance training, where resistance is gradually increased as muscle strength increases, is beneficial for older adults. Structured exercise programmes are likely to be preferable for older adults with frailty, so they can be monitored during exercise to reduce the risk of injury.

Citation and Funding

Villareal DT, Aguirre L, Burke Gurney A, et al. Aerobic or resistance exercise, or both, in dieting obese older adults. N Eng J Med. 2017;376(20):1943-55.

This project was funded by the National Institutes of Health (RO1-AG031176, UL1-TR000041, and P30-DK020579).

Bibliography

Brown M, Sinacore DR, Binder EF, Kohrt WM. Physical and Performance Measures for the Identification of Mild to Moderate Frailty. J Gerontol A Biol Sci Med Sci. 2000;55(6):M350-355.

Department of Health. Department of Health Social Sciences and Public Safety. The Scottish Government. Welsh Government. Fact Sheet 5: physical activity guidelines for older adults (65 + years). 2011.

Han TS, Tajar A, Lean MEJ. Obesity and weight management in the elderly. Br Med Bull. 2011;97(1):169-96.

Liu C, Latham NK. Progressive resistance strength training for improving physical function in older adults. Cochrane Database Syst Rev. 2009;(3):CD002759.

NHS Choices. Exercises for Older People. London: Department of Health; 2014.

NHS Choices. Physical activity guidelines for older adults. London: Department of Health; 2015.

NHS Digital. Statistics on obesity, physical activity and diet. Leeds: 2017.

NHS England. Safe, compassionate care for frail older people using an integrated care pathway: practical guidance for commissioners, providers and nursing, medical and allied health professional leaders. 2014.

Public Health England. Guidance: adult obesity: applying All Our Health. London: 2015.

The British Geriatrics Society. Fit for frailty. Consensus best practice guidance for the care of older people living with frailty in community and outpatient settings. London: 2014.

Why was this study needed?

Obesity is associated with many health problems including heart disease and stroke. Almost a third of people in the UK are obese, costing the NHS around £6.1 billion a year.

Physical frailty is a natural part of ageing but is associated with increased risk of falls and mortality. Obesity can worsen the effects of frailty, but losing weight may cause loss of muscle and bone mass.

Previous studies showed that aerobic and resistance training combined with weight loss improved physical function but didn’t prevent loss of muscle or bone mass or reverse frailty. Aerobic exercise increases cardiovascular fitness with no effect on strength, while resistance training has the opposite effect. The researchers therefore considered that these opposing physiological effects could interfere with each other.

They aimed to compare the two types of exercise when performed alone with the combination of both on preventing frailty during weight loss in older, obese adults.

What did this study do?

This US-based randomised controlled trial included 160 obese adults (aged 65 or more) with mild to moderate frailty as defined by score 18-31 on the Physical Performance Test (PPT).

Participants were assigned to six months of aerobic exercise, resistance training (each 60 minutes three times weekly) or a combination of both (75-90 minutes three times weekly). All groups completed a weight loss programme, including weekly meetings with a dietician, behavioural therapy, and a diet providing an energy deficit of 500-750kcal per day. A control group received no exercise or weight loss programme.

The main outcome was the difference in PPT scores (a composite scale that ranges from 0 to 32 maximum) from start to end of the trial.

Assessors, but not participants, were unaware of group assignment. Participants were mostly female, white, well-educated and physically able to take part. This may limit applicability.

What did it find?

  • People in the combination group showed the greatest improvement in physical function, with an increase of 5.5 (+0.4) points in Physical Performance Test (PPT) scores at six months. This was a 21% increase from the average PPT score at the start of the trial. The change was more than the 1.8 + 2.5 points the authors considered a clinically important difference between groups.
  • The aerobic and resistance groups showed smaller improvements, with both groups showing an increase of 3.9 (+0.4) points in PPT scores, or 14%, from study start. Functional improvements in all exercise groups were significantly greater than the control group (4% score increase).
  • All exercise groups showed a 9% decrease in body weight (<1% in controls), but the combination and resistance groups lost less lean (non-fat) body mass (-1.7kg or -3% and -1.0kg or -2%, respectively) than the aerobic group (- 2.7kg or -5%).
  • There was minimal change in bone mineral density at the hip in the resistance group (-0.006g/cm2 or <1% decrease), but some loss in the combination group (-0.014 g/cm2 or -1.1%), and greatest loss in the aerobic group (-0.027g/cm2 or -2.6%).

What does current guidance say on this issue?

The British Society of Geriatrics best practice guidance (2014) states that exercise improves mobility and function for older people with frailty. They say that strength and balance training are key components but the best exercise regimen remains uncertain.

Department of Health physical activity guidelines (2011) recommend that older adults (65+) should aim to undertake at least 150 minutes of moderate intensity physical activity a week. They should incorporate physical activity both to improve muscle strength and improve balance and co-ordination on at least two days a week. Muscle strengthening exercises may involve using body weights or working against a resistance.

What are the implications?

This study demonstrates the importance of resistance training alongside aerobic exercise to preserve physical function and reduce frailty in older adults. This is consistent with Department of Health advice on muscle strengthening exercises.

It is worth noting the specific population studied. Also, the trial was only of six months duration, so it’s uncertain how long these improvements could be sustained.  

Other studies have shown that progressive resistance training, where resistance is gradually increased as muscle strength increases, is beneficial for older adults. Structured exercise programmes are likely to be preferable for older adults with frailty, so they can be monitored during exercise to reduce the risk of injury.

Citation and Funding

Villareal DT, Aguirre L, Burke Gurney A, et al. Aerobic or resistance exercise, or both, in dieting obese older adults. N Eng J Med. 2017;376(20):1943-55.

This project was funded by the National Institutes of Health (RO1-AG031176, UL1-TR000041, and P30-DK020579).

Bibliography

Brown M, Sinacore DR, Binder EF, Kohrt WM. Physical and Performance Measures for the Identification of Mild to Moderate Frailty. J Gerontol A Biol Sci Med Sci. 2000;55(6):M350-355.

Department of Health. Department of Health Social Sciences and Public Safety. The Scottish Government. Welsh Government. Fact Sheet 5: physical activity guidelines for older adults (65 + years). 2011.

Han TS, Tajar A, Lean MEJ. Obesity and weight management in the elderly. Br Med Bull. 2011;97(1):169-96.

Liu C, Latham NK. Progressive resistance strength training for improving physical function in older adults. Cochrane Database Syst Rev. 2009;(3):CD002759.

NHS Choices. Exercises for Older People. London: Department of Health; 2014.

NHS Choices. Physical activity guidelines for older adults. London: Department of Health; 2015.

NHS Digital. Statistics on obesity, physical activity and diet. Leeds: 2017.

NHS England. Safe, compassionate care for frail older people using an integrated care pathway: practical guidance for commissioners, providers and nursing, medical and allied health professional leaders. 2014.

Public Health England. Guidance: adult obesity: applying All Our Health. London: 2015.

The British Geriatrics Society. Fit for frailty. Consensus best practice guidance for the care of older people living with frailty in community and outpatient settings. London: 2014.

Aerobic or Resistance Exercise, or Both, in Dieting Obese Older Adults

Published on 18 May 2017

Villareal, D. T.,Aguirre, L.,Gurney, A. B.,Waters, D. L.,Sinacore, D. R.,Colombo, E.,Armamento-Villareal, R.,Qualls, C.

N Engl J Med Volume 376 , 2017

BACKGROUND: Obesity causes frailty in older adults; however, weight loss might accelerate age-related loss of muscle and bone mass and resultant sarcopenia and osteopenia. METHODS: In this clinical trial involving 160 obese older adults, we evaluated the effectiveness of several exercise modes in reversing frailty and preventing reduction in muscle and bone mass induced by weight loss. Participants were randomly assigned to a weight-management program plus one of three exercise programs - aerobic training, resistance training, or combined aerobic and resistance training - or to a control group (no weight-management or exercise program). The primary outcome was the change in Physical Performance Test score from baseline to 6 months (scores range from 0 to 36 points; higher scores indicate better performance). Secondary outcomes included changes in other frailty measures, body composition, bone mineral density, and physical functions. RESULTS: A total of 141 participants completed the study. The Physical Performance Test score increased more in the combination group than in the aerobic and resistance groups (27.9 to 33.4 points [21% increase] vs. 29.3 to 33.2 points [14% increase] and 28.8 to 32.7 points [14% increase], respectively; P=0.01 and P=0.02 after Bonferroni correction); the scores increased more in all exercise groups than in the control group (P<0.001 for between-group comparisons). Peak oxygen consumption (milliliters per kilogram of body weight per minute) increased more in the combination and aerobic groups (17.2 to 20.3 [17% increase] and 17.6 to 20.9 [18% increase], respectively) than in the resistance group (17.0 to 18.3 [8% increase]) (P<0.001 for both comparisons). Strength increased more in the combination and resistance groups (272 to 320 kg [18% increase] and 288 to 337 kg [19% increase], respectively) than in the aerobic group (265 to 270 kg [4% increase]) (P<0.001 for both comparisons). Body weight decreased by 9% in all exercise groups but did not change significantly in the control group. Lean mass decreased less in the combination and resistance groups than in the aerobic group (56.5 to 54.8 kg [3% decrease] and 58.1 to 57.1 kg [2% decrease], respectively, vs. 55.0 to 52.3 kg [5% decrease]), as did bone mineral density at the total hip (grams per square centimeter; 1.010 to 0.996 [1% decrease] and 1.047 to 1.041 [0.5% decrease], respectively, vs. 1.018 to 0.991 [3% decrease]) (P<0.05 for all comparisons). Exercise-related adverse events included musculoskeletal injuries. CONCLUSIONS: Of the methods tested, weight loss plus combined aerobic and resistance exercise was the most effective in improving functional status of obese older adults. (Funded by the National Institutes of Health; LITOE ClinicalTrials.gov number, NCT01065636 .).

The Physical Performance Test (PPT) assessed physical frailty by nine tasks: lifting a book, picking up a penny, putting on and removing a coat, standing up from a chair, walking 50 feet, climbing one flight of stairs, testing balance (Romberg test), turning around 360o, and climbing four flights of stairs. Each task is scored from 0 to 4, with a higher score indicating better function. The maximum PTT score is 36. “Not frail” is considered a score of 32-36, mild frailty 25-32, and moderate frailty as 17-24 points. In this study, a change in PPT scores of 1.8 + 2.5 points was considered a clinically important difference between groups.

Expert commentary

One of the major risks of getting older adults to lose weight is that they lose not only body fat, but also lose bone and muscle mass, the two tissues most vital to sustaining good health and high physical function.

This study shows that combining aerobic and resistance exercise leads to better improvements in physical function and aerobic fitness than if the two types of exercise are done separately.

This powerful combination also appears to minimise the loss of muscle and bone that can occur when older adults lose weight. Now we just need to get people to do it!

Janice L Thompson, Professor of Public Health Nutrition & Exercise, University of Birmingham

Expert commentary

Many older adults are obese and this increases the risk of debility, disability, disease and death. Low levels of exercise exacerbate these risks in older adults. Dieting can be effective for combating obesity in older adults but may cause a loss of muscle and bone which increases frailty.

Frail people struggle to perform daily tasks and are less independent. Cardiovascular and resistance exercise minimise muscle and bone loss in older adults (particularly those who are dieting) and maximise physical fitness. This is essential in helping older adults to remain active and healthy and to lead independent and fulfilling lives.

David Stensel, Professor of Exercise Metabolism, Loughborough University

Expert commentary

Reducing weight by altering diet may induce not only fat loss but additional muscle and bone loss. This is a particular problem for older adults because as we age we slowly lose muscle and bone, which is detrimental to health. Losses of muscle and bone due to dieting, on top of age related losses, can ultimately lead to frailty and disability.

When aiming for weight loss, think as much about maintaining muscle and bone as losing fat. Resistance exercise prevents muscle and bone loss and aerobic exercise improves fitness, therefore, ideally, both would be part of a weight loss programme.

Mary Hickson, Professor of Dietetics, University of Plymouth

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  •   Later life, Musculo-skeletal disorders, Obesity and nutrition, Physical therapy