Effect of exercise on night periodic breathing and loop gain during hypoxic confinement

The Effect of Pandemic Movement Restriction Policies on Children's Physical Fitness, Activity, Screen Time, and Sleep

Background: The negative impact of isolation, confinement, and physical (in)activity due to pandemic movement restriction has been well-documented over the past year, but less is known on the impact of these policies on children's physical fitness. This study was designed to determine the effects of pandemic movement restriction policies on the 24-hour movement behavior (24-HMB) of children, and whether any alterations are reflected in worsening physical fitness outcomes determined via direct testing.

Methods: A two-phase, repeated-measures study with matched controls was conducted. Phase One: N = 62 schoolchildren (N = 31 female) completed self-assessment questionnaires on 24-HMB in October 2018 (pre-pandemic) and again in April 2020, at the height of movement restrictions enacted in response to the COVID-19 pandemic first wave. Phase Two: physical fitness of the original N = 62 children were determined directly pre- and post-isolation using an eight-component standardized fitness test battery and compared to N = 62 control children who were matched for age, sex, school region, and fitness centile scores.

Results: During lockdown (total duration: 63 days), moderate-to-vigorous physical activity (MVPA) decreased by ~46 min per day, screen time demonstrated a significant interaction effect, such that kids reported spending less recreational screen time on weekends during lockdown compared to no restriction, and sleep duration was consistently lower (95% CI: −104.1 to −45.5 min, p < 0.001). No interaction effect was present for direct fitness indicators, including: hand tapping (reaction time), standing broad jump, polygon backward obstacle course (coordination), sit-ups, stand-and-reach, bent-arm hang, 60-m, and 600-m run (p ≥ 0.05) although significant main effects are noted for both sexes.

Conclusion: Initial changes in 24-HMB did not translate to reductions in physical fitness per se, likely due to the high initial fitness levels of the children. Further work is needed to confirm whether longer or repeated movement restrictions exacerbate initial negative 24-HMB trends, especially for children who are less fit when restrictions are initiated, prolonged, or repeated.

Respiratory Health Benefits and Risks of Living at Moderate Altitude

Grissom, Colin K., and Barbara E. Jones. Respiratory health benefits and risks of living at moderate altitude. High Alt Med Biol 19:109-115, 2018.-The respiratory system plays a critical role in the series of physiologic responses that occur at high altitude and allows individuals to adapt to and tolerate hypobaric hypoxia. Persons with underlying lung disease may have complications, but sometimes derive benefits, related to residence at high altitude. This review will focus on health benefits and risks of patients with underlying asthma, chronic obstructive pulmonary disease, pulmonary hypertension, or obstructive sleep apnea, who live at altitudes of 1500 to 4500 m. We will also discuss maladaptive responses of the respiratory system at high altitude in previously healthy persons, including development of pulmonary hypertension and sleep-disordered breathing.