ABSTRACT
Exercise and nature exposure are independently recognised for their positive relationship with health, but their combined effects are not fully understood. The present review summarises the evidence that compares physiological and perceptual differences of a single bout of exercise performed outdoors versus indoors. Nine databases were searched for articles published before March 2021 which utilised controlled designs to assess at least one physiological outcome during or after a single acute bout of outdoor exercise. When appropriate, quantitative analyses were completed. Quality of articles was assessed using the Cochrane Risk of Bias Assessment Tool. The findings of 38 articles (Total N = 1168) were examined. Participants were primarily healthy. Summarised outcomes included objective exercise intensity, perceived exertion, performance, neuroendocrine and metabolic responses, cardiovascular responses, thermoregulation, enjoyment, intention for future exercise, and perceptions of the environment. Outdoor environments increased enjoyment (N = 234, K = 10, g = 1.24, 95% CI = [0.59, 1.89], p < 0.001). Findings for remaining outcomes were non-significant or inconclusive and challenging to interpret due to high risk of bias. Overall, outdoor exercise appears to feel more enjoyable than indoor exercise when matched for intensity, with equivocal physiological benefit.
ABSTRACT
High magnitude loading from performing resistance-based exercise has been found to improve tendon strength and reduce symptoms of Achilles tendinopathy (AT) but is difficult to quantify without specialist equipment. Here, we assess the validity and reliability of a novel AT rehabilitation tool (the "PhysViz" system) compared to a "gold-standard" dynamometer for assessing plantarflexion maximal voluntary isometric contractions (MVIC). 41 participants aged 18-60 completed the study. A within-subject test-retest study design was used to examine and compare the validity and reliability of the two systems during plantarflexion MVICs. Test - retest reliability of the two methods were determined by calculating intra-class correlation coefficients (ICCs) and 95% confidence intervals. Method agreement was assessed with Bland - Altman Limits of Agreement (LoA) analysis. The PhysViz demonstrated excellent test-retest reliability; ICC, SEM and MDC were numerically comparable to the dynamometer (ICC 0.93 vs. 0.92; SEM 2.01 vs. 2.95 kg and MDC 5.58 vs. 8.18 kg, respectively), indicating that the novel system is valid and reliable for measuring plantarflexor MVICs. Future studies should address its utility in monitoring AT rehabilitative loading remotely over time.
Subject(s)
Achilles Tendon , Tendinopathy , Humans , Reproducibility of Results , Lower Extremity , Isometric Contraction , Muscle Strength Dynamometer , Muscle StrengthABSTRACT
A growing body of research is exploring the potential added health benefits of exercise when performed outdoors in nature versus indoors. This systematic review aimed to compare the effects of exercise in outdoor environments versus indoor environments on psychological health, physical health, and physical activity behaviour. We searched nine databases from inception to March 2021 for English language, peer-reviewed articles: MEDLINE, Embase, PubMed, Scopus, Web of Science, CINAHL, SportsDiscus, GreenFile, and CENTRAL. We included randomized and non-randomized trials that compared multiple bouts of exercise in outdoor versus indoor environments, and that assessed at least one outcome related to physical health, psychological health, or physical activity behaviour. Due to minimal outcome overlap and a paucity of studies, we performed a narrative synthesis. We identified 10 eligible trials, including 7 randomized controlled trials, and a total of 343 participants. Participant demographics, exercise protocols, and outcomes varied widely. In the 10 eligible studies, a total of 99 comparisons were made between outdoor and indoor exercise; all 25 statistically significant comparisons favoured outdoor exercise. Interpretation of findings was hindered by an overall high risk of bias, unclear reporting, and high outcome heterogeneity. There is limited evidence for added health or behaviour benefits of outdoor exercise versus indoor exercise. Rigorous randomized controlled trials are needed with larger samples and clear reporting.