Personal strategies to mitigate the effects of air pollution exposure during sport and exercise: a narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology.

Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sports and exercise. With the effects of air pollution, pollution episodes (eg, wildfire conflagrations) and climate change becoming increasingly apparent to the general population, so have their impacts on sport and exercise. As such, there has been growing interest in the sporting community (ie, athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed: minimising all exposures by time and distance, monitoring air pollution conditions for locations of interest, limiting outdoor exercise, using acclimation protocols, wearing N95 face masks and using antioxidant supplementation. The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise while recognising the limited evidence base.

COVID-19 Pandemic and Exercise (COPE) trial: a multigroup pragmatic randomised controlled trial examining effects of app-based at-home exercise programs on depressive symptoms.

BACKGROUND: The number of adults across the globe with significant depressive symptoms has grown substantially during the COVID-19 pandemic. The extant literature supports exercise as a potent behaviour that can significantly reduce depressive symptoms in clinical and non-clinical populations. OBJECTIVE: Using a suite of mobile applications, at-home exercise, including high intensity interval training (HIIT) and/or yoga, was completed to reduce depressive symptoms in the general population in the early months of the pandemic. METHODS: A 6-week, parallel, multiarm, pragmatic randomised controlled trial was completed with four groups: (1) HIIT, (2) Yoga, (3) HIIT+yoga, and (4) waitlist control (WLC). Low active, English-speaking, non-retired Canadians aged 18-64 years were included. Depressive symptoms were measured at baseline and weekly following randomisation. RESULTS: A total of 334 participants were randomised to one of four groups. No differences in depressive symptoms were evident at baseline. The results of latent growth modelling showed significant treatment effects in depressive symptoms for each active group compared with the WLC, with small effect sizes (ESs) in the community-based sample of participants. Treatment groups were not significantly different from each other. Effect sizes were very large (eg, week 6 ES range=-2.34 to -2.52) when restricting the analysis only to participants with high depressive symptoms at baseline. CONCLUSIONS: At-home exercise is a potent behaviour to improve mental health in adults during the pandemic, especially in those with increased levels of depressive symptoms. Promotion of at-home exercise may be a global public health target with important personal, social and economic implications as the world emerges scathed by the pandemic. TRIAL REGISTRATION NUMBER: NCT04400279.

Vascular effects of physical activity are not modified by short-term inhaled diesel exhaust: Results of a controlled human exposure study.

BACKGROUND: The combined effects of physical activity and air pollution exposure on vascular function are insufficiently understood, particularly after the inhalation of a ß2-agonist, a vasodilating agent. OBJECTIVE: To assess the micro- and macrovascular response to physical activity after ß2-agonist use while breathing diesel exhaust (DE) in individuals with exercise-induced bronchoconstriction. METHODS: On four exposure visits, eighteen adults inhaled either 400 µg of the ß2-agonist salbutamol or placebo before resting for 60 min, followed by a 30-min cycling bout. During rest and cycling, participants inhaled filtered air (FA) or DE (300 µg/m3 of PM2.5). Microvascular (central retinal arteriolar and venular equivalents, CRAE and CRVE, respectively) and macrovascular parameters (blood pressure (BP)) and heart rate (HR)) were assessed at baseline (T1), 10 min (T2) and 70 min (T3) after cycling. RESULTS: The cycling bout increased CRAE (T2-T1 difference (95th % confidence interval): 4.88 µm (4.73, 5.00 µm), p < 0.001; T3-T1 difference: 2.10 µm (1.62, 2.58 µm), p = 0.031) and CRVE (T2-T1 difference: 3.78 µm (3.63, 3.92 µm), p < 0.001; T3-T1 difference: 3.73 µm (3.63, 3.92 µm), p < 0.001). The exposure to DE had no effect on CRAE (FA-DE difference at T2: 0.46 µm (-0.02, 0.92 µm); p = 0.790; FA-DE difference at T3: 1.76 µm (1.36, 2.16 µm), p = 0.213) and CRVE (FA-DE difference at T2: 0.26 µm (-0.35, 0.88 µm), p = 0.906; FA-DE difference at T3: 0.55 µm (0.05, 1.06 µm), p = 0.750). Compared to T1, systolic BP was decreased at T2 by 2.5 mmHg (2.8, 2.3 mmHg, p = 0.047), independent of inhaled exposure. Heart rate at T2 was significantly increased by 3 bpm (2, 3 bpm, p = 0.025) after the DE-exposure when compared to FA. DISCUSSION: Acute physical activity induces a vasodilatory response in the micro- and macrovasculature in healthy adults by increasing CRAE and CRVE, and by reducing systolic BP post exercise, despite breathing DE. The DE-associated increase in HR might be indicative of an increased sympathetic response to physical activity while breathing DE.

Physiological impacts of atmospheric pollution: Effects of environmental air pollution on exercise.

In this review, we discuss some of the recent advances in our understanding of the physiology of the air pollution and exercise. The key areas covered include the effect of exercise intensity, the effects of pre-exposure to air pollution, acclimation to air pollution, and the utility of masks during exercise. Although higher intensity exercise leads to an increase in the inhaled dose of pollutants for a given distance traveled, the acute effects of (diesel exhaust) air pollution do not appear to be more pronounced. Second, exposure to air pollution outside of exercise bouts seems to have an effect on exercise response, although little research has examined this relationship. Third, humans appear to have an ability to acclimate to ground level ozone, but not other pollutants. And finally, masks may have beneficial effects on certain outcomes at low intensity exercise in pollution with significant levels of particles, but more study is required in realistic conditions.

Inconsistent calculation methodology for the eucapnic voluntary hyperpnoea test affects the diagnosis of exercise-induced bronchoconstriction.

INTRODUCTION: The eucapnic voluntary hyperpnoea (EVH) challenge is used to screen for exercise-induced bronchoconstriction. Several criteria have been proposed to determine the decrease in lung function (fall index, FI) following EVH. We compared three published FI calculation methods to determine if they affect the diagnostic classification. METHODS: The three FIs were calculated for 126 EVH tests. Spirometry was performed in duplicate at baseline and repeated 3, 5, 10, 15 and 20 min following 6 min of EVH. The higher of the two forced expiratory volume in 1 s (FEV1) measures at all time-points post-hyperpnoea was selected for the calculation of the FIs. The FIA was determined as the single lowest of the five postchallenge values, and a test was considered positive if FEV1 decreased ≥10 %. In FIB, a test was considered positive if FEV1 decreased ≥10% at two consecutive post-challenge time-points. The FIC was calculated identically to FIA, but was normalised to the achieved minute ventilation during the EVH challenge. RESULTS: Calculation method affected the raw FIs with FIB generating the smallest and FIC generating the highest values (p<0.001) and a within-subject range of 7%±10%. The number of positive tests differed between the calculation criteria: FIA: 62, FIB: 48 and FIC: 70, p<0.001. Nineteen participants (15%) tested positive in one or two FI methods only, indicating that the FI method used determined whether the test was positive or negative. DISCUSSION: Inconsistency in methodology of calculating the FI leads to differences in the diagnostic rate of the EVH test, with potential implications in both treatment and research outcomes.

High-Dose Inhaled Salbutamol Does Not Improve 10-km Cycling Time Trial Performance.

BACKGROUND: ß2-agonists are on the World Anti-Doping Agency's list of prohibited substances; however, athletes are allowed to treat symptoms of exercise-induced bronchoconstriction with a maximal daily dose of 1600 µg of salbutamol when taken by inhalation. PURPOSE: This study aimed to investigate whether 1600 µg of salbutamol leads to enhanced time trial performance in trained, competitive male cyclists with and without exercise-induced bronchoconstriction on the basis of inhaled dose per kilogram of body weight. METHODS: In a randomized crossover design, 20 trained male cyclists (eight with positive eucapnic voluntary hyperpnea challenge (EVH+) and 12 with negative EVH challenge (EVH-) performed two simulated 10-km time trials on a cycle ergometer 30 min after the inhalation of either 1600 µg of salbutamol or placebo. Lung function, assessed by forced expiratory volume in 1 s (FEV1), was measured immediately before and 15 min after inhalation. The main performance outcome was mean power output. RESULTS: After the inhalation of salbutamol, FEV1 was significantly increased by 6.4% (4.9%) versus 1.0% (4.4%) with placebo (P < 0.001). Despite this increase in FEV1, mean power output during the salbutamol time trial was not increased regardless of relative dose per kilogram of body weight and asthma status. Mean heart rate (P = 0.01), respiratory rate (P = 0.01), minute ventilation (P = 0.03) and perceived leg discomfort (P = 0.03) were significantly increased in the salbutamol condition. CONCLUSIONS: The inhalation of 1600 µg salbutamol improved FEV1 regardless of EVH status but did not improve 10-km time trial performance in trained competitive male cyclists regardless of relative dose per kilogram of body weight or EVH status. Significant increases in heart rate and minute ventilation occurred secondary to stimulation of the adrenergic nervous system.

Patellofemoral pain syndrome in Tibetan Buddhist monks.

Patellofemoral pain syndrome is a common diagnosis in athletes and especially runners. This article discusses 3 cases of patellofemoral pain caused by pronounced inactivity and prolonged knee hyperflexion at altitude in a unique population of Tibetan Buddhist monks. In this case, the monks responded well to a program of activity modification and exercises.