Purpose. The purpose of this study was to investigate the physiological and immunological response of highly trained runners to an intense bout of exercise performed at two different times of day, in a hot, humid environment. Methods. Using a crossover randomized design, 13 highly trained runners (range 64–79 ml·kg⁻¹ min⁻¹) performed a 10 km time trial run in hot (28°C) and humid conditions (70%), at 2 different times of day (09:00 hs and 18:00 hs). Venous blood samples were taken to determine WBCs (white blood cells), IL‐6 (interleukin‐6), CC16 (club cell protein 16), and HSP70 (heat shock protein‐70) concentrations. Upper respiratory tract inflammation was additionally assessed using a nasal lavage procedure. Results. A significant diurnal difference (p < 0.05) was found for core body temperature, total WBC, and neutrophil and lymphocyte concentrations with higher values at 18:00 hs. A phase response in IL‐6, HSP70, WBC, neutrophil, lymphocyte, and CC16 was noted, being more pronounced at 18:00 hs, whilst core body temperature and HR phase responses were more pronounced at 09:00 hs. Conclusion. In hot and humid conditions, athletes may wish to consider, when possible, racing and particularly training in the morning where the least homeostatic perturbation occurs.

Purpose The Clara cell protein CC16, secreted from Clara cells in the lung, is discussed as a potential biomarker for toxic effects on the airways. An increased concentration of CC16 in serum may be caused by increased permeability of the lungs. To investigate the changes in P-CC16 in response to an intense exercise bout performed at different times of day (9 am and 4 pm) of highly trained individuals. Method Using a crossover randomized design, 8 runners (mean VO_2max 71 ml kg⁻¹ min⁻¹, SD 6) performed a 10-km time trial run, at 9 am and 4 pm, in an environmental chamber set at 6 °C. Lung function tests and blood sampling occurred at baseline, immediately post and 1 h post time trial. Result Diurnal differences (P < 0.05) were found for blood neutrophil and lymphocyte counts; with higher values at 4 pm. P-CC16 was higher at the pre- and post-trial time point at 9 am compared to 4 pm. Lung function was not different between or within trials. Conclusion Morning trial in cold condition caused more physiological strain compared to the same trial in the evening. However, this extra stress caused by zeitgebers could be a useful strategy for athletes, coaches, and general population to improve their running performance and protect their health in cold conditions in the long-term plan.

The outbreak of COVID-19 and the changes to normal societal function and in particular quarantine has increased mental distress in many nations. A survey of 22,112 COVID-19-negative quarantined participants in the Kingdom of Saudi Arabia (age: 18–40 years, 42.6%; 40–60 years, 53.3%; over 60 years, 4.1%; mass, 78.9 ± 14.8 kg; stature, 167 ± 8.7 cm) were assessed for depressive symptoms using the online Beck Depression Inventory self-report questionnaire. The relationship between pre-quarantine physical activity and mental health and wellbeing during lockdown has been investigated. A significant difference in body mass index (BMI) between active and inactive participants (p = 0.03) was observed; with females also recording a 3% higher BMI than males. All participants showed a decrease in mental health compared to pre-quarantine. However, pre-quarantine inactivity was found to result in a greater negative impact on mental health and well-being than those active pre-quarantine (p < 0.01). The sedentary population had a 4-fold greater incidence of mild-depression than the active population. This suggests that activity level plays an important role in shielding people from anxiety and stress, whilst it builds mental strength in individuals that can be called upon in trying and difficult situations. Nevertheless, pre-quarantine activity levels did not lead to any significant change in levels of extreme depression in the sample population.

International Journal of Sport Studies for Health

Objectives: Fasting is usually associated with changes in the metabolic, psychological and physiological responses of athletes; advancing and/or delaying their biological clock and therefore, affecting their sport performance. The aim of this study was to assess the effect of Ramadan fasting on blood glucose level, mean arterial pressure (MAP), heart rate (HR) and skin temperature in 11 experienced endurance athletes. Methods: The study was conducted during the third and fourth weeks of Ramadan (26 May - 24 June 2017). Eleven northwest African male endurance runners volunteered to participate in this study (mean ± SD: Age 32 ± 8 years, mass 64 ± 5 kg, and height 1.72 ± 0.05 cm). All participants regularly trained between 18:00 - 19:00; aiming to complete their training close to the time of breaking of fast to allow for rapid rehydration and avoiding any health complications. Blood finger-pricking, blood pressure (BP), HR and skin temperature samples were taken every 2 hours over a 24-hour period during the 3rd or 4th weeks of Ramadan. Data were analysed using a two-way repeated measures ANOVA with Bonferroni-adjusted post hoc tests. Results: A clear within-day variation was revealed in blood glucose concentrations and HR (P < 0.05). Blood glucose concentration variation was directly associated with exercise and food intake but significant peaks were also observed prior to breaking fast. These peaks corresponded to the start of athlete’s usual daily routine and suggest the athletes were able to phase advance blood glucose circadian rhythms. Conclusions: The data presented demonstrates the combination of exercise and fasting phase shifted and adjusted the blood glucose concentration to start rising prior to training session.

Regular exercise is known to boost immunity, increase immune response to fight infection, as well as speeding up recovery times and healing processes. This study seeks to assess if exercising regularly pre-SARS-CoV-2 (COVID-19) and/or BMI status has an effect on recovery time. A total of 215 people infected with COVD-19 from the Kingdom of Saudi Arabia took part in this study (age 36±16 years, mass 72±15 kg, stature 166±11 cm). Only 10 patients were physically active and fulfil WHO physical activity requirement (Age 30±7 years, Mass 77±9 kg, Stature 176±1 cm). There was a significant difference in recovery time between active and inactive patients (P = 0.00) with active patients’ recovery 2.7 times faster than inactive patients. Active patients showed a lower BMI level (p = 0.043). Anthropometric measurement characteristics and the fitness level could be used in decision making scenarios for the estimation of the risk of complications in patients with COVID-19. Novelty: Covid-19 physical active patients shows faster recovery time. Active patients recorded a BMI of over 25kg/m ² , recovered faster than those inactive patients with similar BMI’s.