The physiologic benefits of optimizing cardiorespiratory fitness and physical activity - From the cell to systems level in a post-pandemic world.

Cardiovascular (CV) disease (CVD) is a leading cause of premature death and hospitalization which places a significant strain on health services and economies around the World. Evidence from decades of empirical and observational research demonstrates clear associations between physical activity (PA) and cardiorespiratory fitness (CRF) which can offset the risk of mortality and increase life expectancy and the quality of life in patients. Whilst well documented, the narrative of increased CRF remained pertinent during the coronavirus disease 2019 (COVID-19) pandemic, where individuals with lower levels of CRF had more than double the risk of dying from COVID-19 compared to those with a moderate or high CRF. The need to better understand the mechanisms associated with COVID-19 and those that continue to be affected with persistent symptoms following infection (Long COVID), and CV health is key if we are to be able to effectively target the use of CRF and PA to improve the lives of those suffering its afflictions. Whilst there is a long way to go to optimise PA and CRF for improved health at a population level, particularly in a post-pandemic world, increasing the understanding using a cellular-to-systems approach, we hope to provide further insight into the benefits of engaging in PA.

Effects of Caffeine Ingestion on Human Standing Balance: A Systematic Review of Placebo-Controlled Trials.

Caffeine ingestion may influence balance control via numerous mechanisms. Although previously investigated using various study designs and methods, here we aimed to create the first evidence-based consensus regarding the effects of caffeine on the control of upright stance via systematic review (PROSPERO registration CRD42021226939). Embase, PubMed/MEDLINE, SPORTDiscus and Web of Science databases were searched on 27 January 2021 to identify placebo-controlled trials investigating caffeine-induced changes in human standing balance. Reference lists of eligible studies were also searched. Overall, nine studies involving a total of 290 participants were included. All studies were moderate to strong in quality according to the QualSyst tool. Balance-related outcome measures were collected across a range of different participant ages, stances and sensory conditions. The results show that younger participants' balance was generally unaffected by caffeine ingestion. However, a significant balance impairment was observed following caffeine ingestion in all studies involving older participants (average age >65 years). Our results therefore suggest an age-dependent effect of caffeine ingestion on human standing. Further research into this effect is warranted as only one study has directly compared younger and older adults. Nonetheless, an important implication of our findings is that caffeine ingestion may increase fall risk in older adults. Furthermore, based on our findings, caffeine ingestion should be considered as a potential confounding factor when assessing human standing balance, particularly in older adults.

Anthropometry and performance characteristics of recreational advanced to elite female rock climbers.

Despite climbing's popularity and an increasing number of female participants, there are limited anthropometric and performance data for this population. This study compares the characteristics of 55 experienced female climbers, divided into three categories (lower [ADV-L] and higher advanced [ADV-H] and elite [ELT]) based on self-reported ability. Data on climbing experience, body dimensions, body composition, flexibility, lower and upper-body power and finger strength were assessed. ELT climbers differed significantly from the ADV groups in age (Mean Difference [MD] = 8.8-9.8 yrs; despite smaller differences in years climbing MD = 1.6-2.4 yrs), greater climbing and hours training per week (MD = 3.0-3.7 h & MD = 0.9-1.6 h, respectively), and greater upper-body power (MD = 12.9-16.6 cm) and finger strength (MD = 51.6-65.4 N). Linear regression analysis showed finger strength and upper body power to be associated with ability, particularly when adjusting for descriptive and anthropometric variables (finger strength R2 = 53% and 45%; upper-body power R2 = 60% and 39% for boulder and sport, respectively). The findings support the importance of finger strength and upper-body power; changes in female anthropometric data over the last decade provide insight into the changing nature of the sport.

The effect of Chlorella pyrenoidosa supplementation on immune responses to 2 days of intensified training.

PURPOSE: Periods of intensified training are associated with immune disturbances, The aim was to investigate the effects of supplementation with Chlorella pyrenoidosa (Chlorella) on secretory IgA (sIgA) responses to 2 days intensified training. METHODS: Twenty-six subjects (age 29.1 ± 8.7 years; VO2max 53.7 ± 11.7 ml kg min-1) provided resting saliva samples for determination of sIgA, at baseline (week-0) and following 4, 5, and 6 weeks (weeks-4, -5, -6) of daily supplementation with 6 g/day Chlorella (n = 13) or placebo (PLA, n = 13). During week-4 a 2-day intensified training period was undertaken [morning and afternoon sessions each day, respectively: VO2max test; high-intensity interval training (HIIT, 3 × 30 s Wingate sprints); 90 min at ~60% VO2max; 3 × 30 s HIIT]. RESULTS: Chlorella increased resting sIgA secretion rate (trial × time, P = 0.016: no change with PLA but increases with Chlorella at week-4, week-5 and week-6, P = 0.020, <0.001, and 0.016). PLA vs Chlorella: week-0 = 54 ± 33 vs 57 ± 37 µg/min; week-4 = 54 ± 35 vs 83 ± 57 µg/min; week-5 = 63 ± 46 vs 98 ± 47 µg/min; week-6 = 58 ± 35 vs 85 ± 59 µg/min. Minimal acute changes in sIgA were seen in response to individual exercise bouts, but it was higher at some times in the Chlorella group (for bouts 2 and 3). CONCLUSION: Supplementation with Chlorella has beneficial effects on resting sIgA, which might be beneficial during periods of intensified training.