Effects of once- versus twice-weekly eccentric resistance training on muscular function and structure in older adults: a randomised controlled trial.

Adherence rates to current twice-weekly strength training guidelines are poor among older adults. Eccentric-only training elicits substantial improvements in muscle function/size so the aim of this study was to compare the effects of once- versus twice-weekly eccentric training programmes on muscle function/size in older adults. Thirty-six participants (69.4 ± 6.0 yr) were randomised into non-active control, once-, or twice-weekly training groups. Lower-limb muscle power, strength, and size were assessed at baseline, mid-, and post-eccentric training. Training was performed for 12 min per session at 50% of maximum eccentric strength. Significant increases in power (13%), isometric (17-36%) and eccentric (40-50%) strength, and VL muscle thickness (9-18%) occurred in both training groups following 12 weeks. Minimal muscle soreness was induced throughout the 12 weeks and perceived exertion was consistently lower in the twice-weekly training group. One weekly submaximal eccentric resistance training session over 12 weeks elicits similar improvements in neuromuscular function compared to the currently recommended twice-weekly training dose. Given the substantial improvements in neuromuscular function and previously reported low adherence to current twice-weekly training guidelines, eccentric training may be pivotal to developing a minimal-dose strategy to counteract neuromuscular decline. The trial was registered retrospectively on 24/01/2024 with ISRCTN (trial registration number: ISRCTN68730580).

Delapré Walk project: Are signposted walking routes an effective intervention to increase engagement in urban parks? -Natural experimental study.

Spatial education interventions in the built environment may increase engagement with urban greenspace. This research was a natural experimental study with mixed-method evaluation and repeated cross-sectional design. Twenty-four directional wayfinding signs were installed within an urban park to create a 3 km signposted walking route through the park's amenities in a clockwise direction. Manual counts on one path and bi-directional automated active infrared counts on six paths along the intervention route were conducted at baseline and 12-month follow-up. A QR code accessed intercept survey was open throughout the follow-up phase to capture user experiences, views, and attitudes toward the intervention. There was no consistent difference in manual counts at baseline or 12-month follow-up between intervention and control parks. Automated counts showed no consistent significant change in clockwise footfall between baseline (median automated count range across six counters: 10-130 clockwise counts per day) and follow-up (Autumn to Winter follow-up median automated count range across six counters: 13-103 clockwise counts per day; Spring to Summer follow-up median automated count range across six counters: 13-124 clockwise counts per day). However, 23% (11 out of 48 people) of clockwise travelling route users reported they were following the signs at 12-month follow-up. Intercept survey respondents (n = 27) appeared to be infrequent park users (number of respondents for 'my first visit': 7, and 'one to two times per month: 9), with the new signs making them feel less anxious about exploring unfamiliar areas, while motivating them to walk further than originally planned and helping them to 'take notice' of the landscape. Directional wayfinding for recreational walking appears to help infrequent users engage with urban greenspace.

The acute and repeated bout effects of multi-joint eccentric exercise on physical function and balance in older adults.

PURPOSE: Eccentric muscle actions generate high levels of force at a low metabolic cost, making them a suitable training modality to combat age-related neuromuscular decline. The temporary muscle soreness associated with high intensity eccentric contractions may explain their limited use in clinical exercise prescription, however any discomfort is often alleviated after the initial bout (repeated bout effect). Therefore, the aims of the present study were to examine the acute and repeated bout effects of eccentric contractions on neuromuscular factors associated with the risk of falling in older adults. METHODS: Balance, functional ability [timed up-and-go and sit-to-stand], and lower-limb maximal and explosive strength were measured in 13 participants (67.6 ± 4.9 year) pre- and post-eccentric exercise (0, 24, 48, and 72 hr) in Bout 1 and 14 days later in Bout 2. The eccentric exercise intervention was performed on an isokinetic unilateral stepper ergometer at 50% of maximal eccentric strength at 18 step‧min-1 per limb for 7 min (126 steps per limb). Two-way repeated measures ANOVAs were conducted to identify any significant effects (P ≤ 0.05). RESULTS: Eccentric strength significantly decreased (- 13%) in Bout 1 at 24 hr post-exercise; no significant reduction was observed at any other time-point after Bout 1. No significant reductions occurred in static balance or functional ability at any time-point in either bout. CONCLUSION: Submaximal multi-joint eccentric exercise results in minimal disruption to neuromuscular function associated with falls in older adults after the initial bout.

Influence of COVID-19 Building Restrictions on Physical Activity Promotion Through Increased Stair Use and Limited Elevator Access: A Quasi-Experimental Study-Sport and Physical Activity Group Active Campus Project.

BACKGROUND: The aim of this study was to determine the effectiveness of UK government COVID-19 safe offices policy to increase stair use in a higher education setting during the COVID-19 pandemic. METHODS: Automated counts at 3 ground floor staircases and the elevator entrances were used to estimate stair to elevator use ratio for ascent and descent from/to the ground floor of a university building at baseline (January to March 2020), first and second intervention months (October 2020, November 2020, respectively). Stair promoting signage and a 1-way system was implemented, in line with government policy. RESULTS: At baseline, stair to elevator use ratio for ascent from and descent to the ground floor was 1.36 (0.02) and 1.88 (0.02) people, respectively. The ratio significantly increased in the first intervention month to 2.64 (0.09) and 3.96 (0.22) people for ascent and descent, respectively. However, the ratio decreased between the first and second intervention months to 1.63 (0.06) and 3.05 (0.52) people for ascent and descent, respectively. CONCLUSION: The UK government COVID-19 policy was effective at increasing stair use in a higher education setting.

Using isotemporal substitution to predict the effects of changing physical behaviour on older adults' cardio-metabolic profiles.

BACKGROUND: It has been advocated that older adults should concomitantly spend less time in sedentary behaviour (SB), and engage in sufficient physical activity (PA), to reduce their risk of cardio-metabolic diseases. However, it is not clear what intensity of PA must be done to offset SB engagement. AIM: Model how cardio-metabolic profiles could change if older adults replaced an hour per day (hr·day-1) of a physical behaviour intensity with 1 hr·day-1 of another physical behaviour of a different intensity. METHODS: Older adults (n = 93, 60-89 years old, 55% female) wore a thigh-mounted triaxial accelerometer for seven consecutive free-living days to estimate mean daily hourly engagement in SB, Standing, Light Intensity PA (LIPA), sporadic moderate to vigorous physical activity (sMVPA, bouts <10 continuous minutes), and 10-minute MVPA (10MVPA, bouts ≥10 continuous minutes. Fasting whole blood concentration of plasma glucose, triglyceride, total cholesterol, and glycated haemoglobin (%), along with serum concentration of lipoprotein lipase (LPL), interleukin-6 (IL-6), and procollagen III N-terminal propeptide (PIIINP) were measured. RESULTS: Isotemporal Substitution, with covariate adjustment, suggested that: total cholesterol concentration could theoretically decrease when 1 hr·day-1 of SB is replaced with Standing, when 1 hr.day-1 of LIPA is replaced with Standing, and when 1 hr·day-1 of sMVPA is replaced with Standing. Triglyceride concentration theoretically decreased when 1 hr·day-1 of SB, Standing, LIPA, or sMVPA is replaced with 10MVPA. Triglyceride concentration theoretically increases when 1 hr·day-1 of 10MVPA is replaced with SB, Standing, or LIPA. No associations with time reallocation appears to exist for LPL, HbA1c, IL-6, and PIIINP. CONCLUSION: The type of physical behaviour being replaced could be crucial for total cholesterol maintenance. Engagement in 10MVPA could be necessary to improve triglyceride concentration.

Reliability and validity of the international physical activity questionnaire compared to calibrated accelerometer cut-off points in the quantification of sedentary behaviour and physical activity in older adults.

BACKGROUND: The aim was to determine the reliability and validity of IPAQ measured sedentary behaviour (SB) and moderate-vigorous physical activity (MVPA) in older persons whilst examining any sex differences in reliability and validity results. METHOD: 89 participants (73.7 ± 6.3 years, 54% female) completed the IPAQ. Participants were fitted with a thigh mounted triaxial accelerometer (GeneActiv Original) for seven consecutive days and subsequently completed a second IPAQ. RESULTS: IPAQ showed weak reliability qualities for Total SB (h·week-1) and 10 minute MVPA (accumulated in bouts ≥ 10 continuous minutes, h·week-1). IPAQ had poor concurrent validity qualities for Total SB, 10 minute MVPA, but not Sporadic MVPA (accumulated in bouts < 10 continuous minutes, h·week-1). IPAQ only categorised participant physical behaviour classification correctly 2% of the time. Sex differences were only present for the correlation slope of IPAQ 10 minute MVPA reliability measures. CONCLUSION: Our data suggests that the IPAQ is not suitable for assessing older adults habitual physical behaviour.

Segregating the Distinct Effects of Sedentary Behavior and Physical Activity on Older Adults' Cardiovascular Profile: Part 2-Isotemporal Substitution Approach.

BACKGROUND: The aim of the study was to provide an isotemporal substitution model to predict how changes in physical behavior may affect the cardiovascular parameters (CVPs) of older adults. METHODS: Participants wore a thigh-mounted accelerometer for 7 days. Phenotype of the carotid, brachial, and popliteal artery was conducted using ultrasound. Isotemporal substitution was used to simulate the degree to which replacing 1 hour of physical behavior with another would affect CVP. RESULTS: Substitution of sedentary behavior with Standing and sporadic moderate- to vigorous-intensity physical activity (MVPA accumulated in bouts <10 min) would reduce resting heart rate [-6.20 beats per minute (-12.1 to -0.22) and -3.72 beats per minute (-7.01 to -0.44), respectively]. Substitution of sedentary behavior with light-intensity physical activity would reduce carotid artery diameter [-0.54 mm (-1.00 to -0.07)]. Substitution of Standing with sporadic MVPA would increase popliteal artery diameter [1.31 mm (0.11 to 2.51)]. CONCLUSIONS: Our modeling suggests that an accumulation of MVPA bouts that are shorter than the recommended 10-minute minimum may still improve CVP, with lower intensity physical activity also influencing CVP. Our findings are a promising avenue for lifestyle interventions in older adults to reduce the aging effects on CVP for those who cannot engage or sustain sufficient MVPA.