Moderate-intensity stepping in older adults: insights from treadmill walking and daily living.

BACKGROUND: A step cadence of 100 steps/minute is widely used to define moderate-intensity walking. However, the generalizability of this threshold to different populations needs further research. We investigate moderate-intensity step cadence values during treadmill walking and daily living in older adults. METHODS: Older adults (≥ 60 years) were recruited from urban community venues. Data collection included 7 days of physical activity measured by an activPAL3™ thigh worn device, followed by a laboratory visit involving a 60-min assessment of resting metabolic rate, then a treadmill assessment with expired gas measured using a breath-by-breath analyser and steps measured by an activPAL3™. Treadmill stages were undertaken in a random order and lasted 5 min each at speeds of 1, 2, 3, 4 and 5 km/h. Metabolic equivalent values were determined for each stage as standardised values (METSstandard) and as multiples of resting metabolic rate (METSrelative). A value of 3 METSstandard defined moderate-intensity stepping. Segmented generalised estimating equations modelled the association between step cadence and MET values. RESULTS: The study included 53 participants (median age = 75, years, BMI = 28.0 kg/m2, 45.3% women). At 2 km/h, the median METSstandard and METSrelative values were above 3 with a median cadence of 81.00 (IQR 72.00, 88.67) steps/minute. The predicted cadence at 3 METSstandard was 70.3 (95% CI 61.4, 75.8) steps/minute. During free-living, participants undertook median (IQR) of 6988 (5933, 9211) steps/day, of which 2554 (1297, 4456) steps/day were undertaken in continuous stepping bouts lasting ≥ 1 min. For bouted daily steps, 96.4% (90.7%, 98.9%) were undertaken at ≥ 70 steps/minute. CONCLUSION: A threshold as low as 70 steps/minute may be reflective of moderate-intensity stepping in older adults, with the vast majority of all bouted free-living stepping occurring above this threshold.

The effects of supervised exercise training 12-24 months after bariatric surgery on physical function and body composition: a randomised controlled trial.

BACKGROUND: Bariatric surgery is effective for the treatment of stage II and III obesity and its related diseases, although increasing evidence is showing weight regain ~12-24 months postsurgery. Weight regain increases the risk of physical function decline, which negatively affects an individual's ability to undertake activities of daily living. The study assessed the effects of a 12-week supervised exercise intervention on physical function and body composition in patients between 12 and 24 months post bariatric surgery. METHODS: Twenty-four inactive adult bariatric surgery patients whose body mass index remained ⩾30 kg m2 12 to 24 months post surgery were randomised to an exercise intervention (n=12) or control group (n=12). Supervised exercise consisted of three 60-min gym sessions per week of moderate intensity aerobic and resistance training for 12 weeks. Control participants received usual care. The incremental shuttle walk test (ISWT) was used to assess functional walking performance after the 12-week exercise intervention, and at 24 weeks follow-up. Measures of anthropometric, physical activity, cardiovascular and psychological outcomes were also examined. Using an intention-to-treat protocol, independent t-tests were used to compare outcome measures between groups. RESULTS: Significant improvements in the exercise group were observed for the ISWT, body composition, physical function, cardiovascular and self-efficacy measures from baseline to 12 weeks. A large baseline to 12-week change was observed for the ISWT (exercise: 325.00±117.28 m; control: 355.00±80.62 m, P<0.001). The exercise group at 24 weeks recorded an overall mean improvement of 143.3±86.6 m and the control group recorded a reduction of -32.50±75.93 m. Findings show a 5.6 kg difference between groups in body mass change from baseline to 24 weeks favouring the exercise group. CONCLUSIONS: A 12-week supervised exercise intervention led to significant improvements in body mass and functional walking ability post intervention, with further improvements at the 24-week follow-up.

Changes in physical activity behaviour and physical function after bariatric surgery: a systematic review and meta-analysis.

Although physical activity performed after bariatric surgery is associated with enhanced weight loss outcomes, there is limited information on patients' physical activity behaviour in this context. This systematic review and meta-analysis assessed pre-operative to post-operative changes in physical activity and physical function outcomes among obese adults undergoing bariatric surgery. A total of 50 studies met inclusion criteria with 26 papers reporting data for meta-analysis. Increases in both objectively recorded and self-reported physical activity at 12 months were demonstrated. Studies indicated that there was a shift towards a greater amount of active time, but of a lower intensity within the first 6 months of bariatric surgery, suggested by a reduction in moderate to vigorous physical activity but an increase in step count. A standardized mean difference (SMD) of 1.53 (95% CI: 1.02-2.04) based on nine studies indicated improved walking performance at 12 months. Similarly, analysis of five studies demonstrated increased musculoskeletal function at 3-6 months (SMD: 1.51; 95% CI: 0.60-2.42). No relationship was identified between changes in weight and walking performance post-surgery. More studies assessing physical activity, physical function and weight loss would help understand the role of physical activity in optimizing post-operative weight and functional outcomes.

The efficacy of 12 weeks supervised exercise in obesity management.

The objective of this randomized controlled trial was to investigate the effect of adding either aerobic training (AT) or resistance training (RT) to a multidisciplinary teamed (MDT) educational weight management programme on the health-related fitness of morbidly obese individuals. Males (n = 9) and females (n = 24) aged between 24 and 68 years with a body mass index (BMI) of ≥40 kg m(2) (≥35 kg m(2) with comorbidities) undertaking a weight management programme were recruited (Completion: M = 8, F = 19). Participants were randomly allocated to either AT (n = 12), RT (n = 11) or CON (n = 10). AT and RT undertook three structured ∼60 min moderate intensity sessions weekly, two supervised gym-based and one structured home-based session for 12 weeks; CON undertook usual care alone. Anthropometric, psychological and functional capacity measures were obtained pre- and post-intervention. Both exercise interventions elicited improvements compared with CON in the: shuttle walk test (AT [Δ 207.0 ± 123.0 metres, 68.0%, P = 0.04], RT [Δ 165.0 ± 183.3 m, 48.8%, P = 0.06], CON [Δ -14.3 ± 38.7 m, -6.2%]), triceps skin-fold (P ≤ 0.001), self-efficacy (P = 0.005) and interest/enjoyment (P = 0.006). RT displayed additional improvements compared with CON in BMI (RT [Δ -1.02 ± 0.91 kg·m(2) , -2.5%, P = 0.033], AT [Δ -1.84 ± 2.70 kg·m(2) , -4.3%, P = 0.142], CON [Δ -0.31 ± 1.47 kg·m(2) , -0.6%]), waist circumference (P = 0.022), competence (P = 0.019), biceps skin-fold (P = 0.012) and medial calf skin-fold (P = 0.013). No significant differences were observed between exercise modalities. Regardless of exercise mode, the addition of supervised and structured exercise to a MDT weight management programme significantly improved anthropometric, functional and psychological measures in obese participants with a BMI of ≥35 kg·m(2) .