No abstract

Prescription characteristics and guidelines of recommended physical activity have been suggested as factors that may affect behavioural adherence; however, no review has critically appraised the current evidence. Thus, the purpose of this article was to review the effect of frequency, intensity, duration and mode on physical activity adherence and provide meta-analytical summaries of the findings. A total of 27 peer-reviewed studies met inclusion criteria and random-effects meta-analytical procedures, correcting for sampling bias, were employed where possible. Overall, results showed that the effect of physical activity guideline characteristics on behavioural adherence is not particularly robust as evidenced by a lack of unified findings and almost no evidence for the interaction among these factors (e.g. volume of activity and energy expenditure). Frequency (d = 0.08), intensity (d = 0.02), duration (d = 0.05) and mode of activity (ds = 0.03-0.10) showed generally null/trivial effects. Factors unrelated to the recommended guidelines may be of greater importance when considering behavioural adherence issues. Social cognitive, personality, and environmental or socioeconomic factors have amassed considerable evidence as correlates or determinants of physical activity, and health promoters may wish to consider these variables before basic physical activity characteristics.

The impact of hydration status was investigated during a 5‐day heat acclimation (HA) training protocol vs mild/cool control conditions on plasma volume (PV) and performance (20 km time‐trial [TT]). Sub‐elite athletes were allocated to one of two heat training groups (90 min/day): (a) dehydrated to ~2% body weight (BW) loss in heat (35°C; DEH; n = 14); (b) euhydrated heat (35°C; EUH; n = 10), where training was isothermally clamped to 38.5°C core temperature (Tc). A euhydrated mild control group (22°C; CON; n = 9) was later added, with training clamped to the same relative heart rate (~75% HRmax) as elicited during DEH and EUH; thus all groups experienced the same internal training stress (%HRmax). Five‐day total thermal load was 30% greater (P < 0.001) in DEH and EUH vs CON. There were significant differences in the average percentage of maximal work rate (%Wmax) across all groups (DEH: 24 ± 6%; EUH: 34 ± 9%; CON: 48 ± 8%Wmax) during training required to elicit the same %HRmax (77 ± 4% HRmax). There were no significant differences pre‐to post‐HA between groups for PV (DEH: +1.7 ± 10.1%; EUH: +4.8 ± 10.2%; CON: +5.2 ± 4.0%), but there was a significant pooled group PV increase, as well as a 97% likely pooled improvement in TT performance (DEH: −1.8 ± 2.8%; EUH: −1.9 ± 2.1%, CON; −1.8 ± 2.8%; P = 0.136). Due to a lack of between‐group differences for PV and TT, but pooled group increases in PV and 97% likely group increase in TT performance, over 5 days of intense training at the same average relative cardiac load suggests that overall training stress may also impact significant adaptations beyond heat and hydration stress.

Dog walking is receiving increasing attention in the public health literature as a strategy to improve dog guardians' physical activity levels. Quantitative research suggests that dog guardians walk more often and for longer than non dog-guardians, and offers suggestions as to the reasons for these differences. The purpose of this study was to qualitatively explore dog guardians' walking practices and relationships with their dogs, to better understand how and why dog walking might become an intervention point to enhance physical activity levels. Five focus groups and two interviews were conducted with 16 adult dog guardians. Following an initial analysis of the results, 10 additional dog guardians were individually interviewed to review and confirm the findings. Four themes emerged to explain the dog-walking phenomenon: Transcending the human-animal distinction; Dogs as walking sole mates; Activity/health benefits; and Dogs as social conduits. We argue that an empathetic stance benefits dog guardians because, as valued family members whose health and happiness they are responsible for, their canine companions serve to motivate, enable, and sustain walking behaviors.