of muscle and bone mass and reduced resting metabolic rate, which otherwise accompanies hypocaloric dieting; increase glucose uptake and storage in skeletal muscle; reduce visceral fat depots; and reduce C‐reactive protein,155,156 as well as its beneficial effects on resting blood pressure, functional status, mobility, sleep,157 and depressive symptoms. The effects on muscle mass are unique to high‐intensity resistance training and clearly distinguish it from aerobic exercise. For this reason, current recommendations include both aerobic and resistance training as well as dietary modification for type 2 diabetes. A summary of the major trials on which such recommendations to include resistance training for treatment of type 2 diabetes have been based is presented in Table 7.8.
Table 7.8 Major randomised controlled trials including resistance training in type 2 diabetes.
| Study | N (average age) | Duration of training (months) | Resistance training intensity | Other additional intervention | Significant improvement in insulin sensitivity or glucose homeostasis |
|---|---|---|---|---|---|
| Dunstan et al.33,34 | 36 (60–80 years) | 2 (6 months supervised) | High | Moderate weight loss programme | Yes, for supervised phase but not home‐based, free‐weight phase |
| Balducci et al.158 | 120 (60.9 years) | 12 | Moderate | Aerobic at 40–80% HR | Yes |
| Baldi and Snowling159 | 18 (46.5 years) | 2.5 | Moderate | None | Yes |
| Cuff et al.160 | 28 (60.0 years) | 4 | Low | Aerobic at 60–75% HR | Yes |
| Loimaala et al.161 | 50 (53.8 years) | 11 | High | Aerobic at 65–75% HR | Yes |
| Castaneda et al.77 | 62 (66 years) | 4 | High | None | Yes |
| Dunstan et al.162 | 27 (51 years) | 2 | Moderate | Low‐intensity cycling between each set | Yes |
| Ibañez et al.78 | 9 (66.6 years) | 4 | High | None | Yes |
| Rodriguez‐Mañas et al.163 | 964 (78.4 years) | 4 | High | Nutritional and educational programme | Yes |
| Mavros et al.164 | 103 (65 years) | 12 | High, power training | None Control = low‐intensity resistance training | No, but metabolic benefits proportional to body composition changes |
Evidence for exercise interventions in frail older adults with diabetes
Ageing patients with type 2 diabetes exhibit greater declines in muscle strength and functional capacity and more rapid loss of muscle mass than normoglycaemic controls.165,166 Indeed, diabetes complications such as peripheral vascular disease and peripheral neuropathy are associated with poor gait ability, impaired balance, and increased risk of falls.165,166 In frail patients with diabetes, enhancement in functional capacity is crucial and may be more beneficial than attention to metabolic control alone.167 Accordingly, an important conceptual idea is that the focus in older people with diabetes should be on functionality.168 Therefore, in addition to metabolic control, effective strategies are needed to prevent the exacerbated loss of strength and functional capacity in ageing adults with diabetes because these individuals exhibit an increased risk of the development of frailty syndrome, institutionalisation, and disability.11,59,126‐127
Thus, exercise interventions, including resistance training, together with pharmacological and dietary interventions, represent the cornerstones of type 2 diabetes mellitus management.151,169 Along with the beneficial effects of exercise interventions for older adults with diabetes on glycaemic control,151,169 increased insulin sensitivity, decreased amount of intra‐abdominal adipose tissue and muscle fat infiltration,78 and the cardiovascular risk factors associated with diabetes,22 physical exercise improves muscle mass, strength, power output, cardiovascular function, and functional capacity,78 as it does in healthy elders. It may also help prevent dementia in older adults with diabetes,4 although systematic review indicates more study is needed.170 In frail older people with diabetes with functional decline, multicomponent exercise programmes composed of resistance, endurance, balance, and gait retraining should be employed to increase functional capacity and quality of life and avoid falls, institutionalisation, and disability.147 Furthermore, because muscle power is an important predictor of functional capacity, strategies to develop skeletal muscle power in this population must be included to prevent or postpone functional limitations and subsequent disability.4,17,52,171
Exercise to counteract iatrogenic disease
Finally, exercise may counteract undesirable side effects of standard medical care, a use of exercise that is just emerging in the literature. Such use of exercise would include resistance training for patients receiving corticosteroid treatment to counteract the associated proximal myopathy and osteopenia, substituting exercise for psychotropic medications to prevent falls,172 or neutralising the adverse effects of energy‐restricted diets in obesity or protein‐restricted diets in chronic renal failure,173 for example.
Osteopenia associated with corticosteroid usage appears to be eliminated by concurrent progressive resistance training, which should be recommended for all such patients. Although bisphosphonates have also been shown to be very effective for corticosteroid osteopenia, they do not address the coexisting steroid myopathy as resistance training does and are therefore an insufficient antidote for corticosteroid side effects. An excellent target group for such health promotion efforts would be older men with steroid‐dependent chronic lung disease, in whom pulmonary cachexia, malnutrition, tobacco use, steroid myopathy, and osteoporosis combine to produce profound wasting, osteoporotic fracture, and impaired exercise tolerance. Aerobic training will improve functional status in this clinical cohort but is insufficient to address musculoskeletal
