The Reliability and Validity of Fatigue Measures During Multiple-Sprint Work: An Issue Revisited

The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 × 30-m sprints repeated every 35 seconds; protocol 2 consisted of 12 × 30-m sprints repeated every 65 seconds. All testing was performed in an indoor sports facility, and sprint times were recorded using twin-beam photocells. All but one of the formulae showed good construct validity, as evidenced by similar within-protocol fatigue scores. However, the assumptions on which many of the formulae were based, combined with poor or inconsistent test-retest reliability (coefficient of variation range: 0.8-145.7%; intraclass correlation coefficient range: 0.09-0.75), suggested many problems regarding logical validity. In line with previous research, the results support the percentage decrement calculation as the most valid and reliable method of quantifying fatigue in tests of multiple-sprint performance

Perceptual and Physiological Responses to Recovery from a Maximal 30-Second Sprint

The aims of this study were to evaluate perceptions of post-exercise recovery and to compare patterns of perceived recovery with those of several potential mediating physiological variables. Seventeen well-trained men (age: 22 ± 4 years; height: 1.83 ± 0.05 m; body mass: 78.9 ± 7.6 kg; and body fat: 11.1 ± 2.2%) completed 10 sprint trials on an electromagnetically braked cycle ergometer. Trial 1 evaluated peak power via a 5-second sprint. The remaining trials evaluated (a) the recovery of peak power after a maximal 30-second sprint using rest intervals of 5, 10, 20, 40, 80, and 160 seconds; (b) perceived recovery via visual analog scales; and (c) physiological responses during recovery. The time point in recovery at which individuals perceived they had fully recovered was 163.3 ± 57.5 seconds. Power output at that same time point was 83.6 ± 5.2% of peak power. There were no significant differences between perceived recovery and the recovery processes of VO2 or minute ventilation (VE). Despite differences in the time courses of perceived recovery and the recovery of power output, individuals were able to closely predict full recovery without the need for external timepieces. Moreover, the time course of perceived recovery is similar to that of VO2 and VE

The influence of aerobic fitness on the recovery of peak power output

Purpose The aims of this study were to evaluate the recovery kinetics of peak power output (PPO) following a maximal sprint, and to evaluate the influence of aerobic fitness on that recovery process. Methods On separate occasions, 16 well-trained men (age: 21 ± 3 years; height: 1.84 ± 0.05 m; and body mass: 78.8 ± 7.8 kg) performed a 30 s maximal sprint on a cycle ergometer, followed by a predetermined stationary rest period (5, 10, 20, 40, 80, and 160 s) and a subsequent 5 s sprint to determine PPO recovery kinetics. On another occasion, V ˙ O 2 was monitored during recovery from a 30 s sprint to provide a comparison with the recovery of PPO. Finally, subjects completed a V ˙ O 2max test to evaluate the influence of aerobic fitness on the recovery of PPO. Results Despite following similar time courses (F = 0.36, p = 0.558), and being well described by double-exponential models, the kinetic parameters of PPO and V ˙ O 2 in recovery were significantly different (p < 0.05). There was no significant relationship (r = 0.15; p = 0.578) between V ˙ O 2max and the time to achieve 50 % recovery of PPO. Moreover, there was no difference (p = 0.61) between the recovery kinetics of participants classified according to their V ˙ O 2max (59.4 ± 1.3 vs 48.5 ± 2.2 ml·kg−1·min−1). Conclusion Despite similar overall recovery kinetics, V ˙ O 2 and PPO show differences in key model parameters. Moreover, the recovery of PPO does not appear to be affected by aerobic fitness

Caffeine and sprint cycling performance: effects of torque factor and sprint duration

Purpose: The aim of this study was to investigate the influence of torque factor and sprint duration on the effects of caffeine on sprint cycling performance. Methods: Using a counterbalanced, randomized, double-blind, placebo-controlled design, 13 men completed nine trials. In Trial 1, participants completed a series of 6 s sprints at increasing torque factors, to determine the torque factor, for each individual, which elicited the highest (TOPTIMAL) peak power output (PPO). The remaining trials involved all combinations of torque factor (0.8 N∙m∙kg-1 versus TOPTIMAL), sprint duration (10 s versus 30 s), and supplementation (caffeine [5mg∙kg-1] versus placebo). Results: There was a significant effect of torque factor on PPO, with higher values at TOPTIMAL (mean difference: 168 W; 95% likely range: 142 – 195 W). There was also a significant effect of sprint duration on PPO, with higher values in 10 s sprints (mean difference: 52 W; 95% likely range: 18 – 86 W). However, there was no effect of supplementation on PPO (p = 0.056). Nevertheless, there was a significant torque factor × sprint duration × supplement interaction (p = 0.036), with post hoc tests revealing that caffeine produced a higher PPO (mean difference: 76 W; 95% likely range: 19 – 133 W) when the sprint duration was 10 s and the torque factor was TOPTIMAL. Conclusions: The results of this study show that when torque factor and sprint duration are optimized, to allow participants to express their highest PPO, there is a clear effect of caffeine on sprinting performance

Caffeine and Sprinting Performance: Dose Responses and Efficacy

The aims of this study were to evaluate the effects of caffeine supplementation on sprint cycling performance and to determine if there was a dose-response effect. Using a randomized, double-blind, placebo-controlled design, 17 well-trained men (age: 24 ± 6 years, height: 1.82 ± 0.06 m, and body mass(bm): 82.2 ± 6.9 kg) completed 7 maximal 10-second sprint trials on an electromagnetically braked cycle ergometer. Apart from trial 1 (familiarization), all the trials involved subjects ingesting a gelatine capsule containing either caffeine or placebo (maltodextrin) 1 hour before each sprint. To examine dose-response effects, caffeine doses of 2, 4, 6, 8, and 10 mg·kg bm−1 were used. There were no significant (p ≥ 0.05) differences in baseline measures of plasma caffeine concentration before each trial (grand mean: 0.14 ± 0.28 μg·ml−1). There was, however, a significant supplement × time interaction (p < 0.001), with larger caffeine doses producing higher postsupplementation plasma caffeine levels. In comparison with placebo, caffeine had no significant effect on peak power (p = 0.11), mean power (p = 0.55), or time to peak power (p = 0.17). There was also no significant effect of supplementation on pretrial blood lactate (p = 0.58), but there was a significant time effect (p = 0.001), with blood lactate reducing over the 50 minute postsupplementation rest period from 1.29 ± 0.36 to 1.06 ± 0.33 mmol·L−1. The results of this study show that caffeine supplementation has no effect on short-duration sprint cycling performance, irrespective of the dosage used

The impact of COVID-19 on the mental wellbeing of health and social care workers in Scotland

Background: Recent studies published during the COVID-19 pandemic have reported that the mental wellbeing of health and social care workers (HSCWs) has been adversely impacted. Research has yet to explore what factors may help HSCWs positively adapt in the face of the adversities endured during the pandemic. Methods: The study consisted of a cross-sectional online survey exploring the impact of COVID-19 on the mental wellbeing of HSCWs (n= 1300+). The survey included both closed and open-ended questions exploring COVID-19 perceived risks, stress, burnout and mental wellbeing as well as coping and team resilience. Both quantitative and qualitative content analysis of the online survey data was conducted. Expected results: Data collection began in December 2020 and data collection and analysis is due for completion in June 2021. Preliminary analysis suggested that access to PPE, psychological input and increased perceived team resilience and peer support helped mitigate against the adverse impact that COVID-19 related stressors have on HSCW's mental wellbeing. Visible leadership was also found to be essential in helping staff gain access to current and accurate information on COVID-19 and in helping workers adapt to constant change. Discussion: The implications of these findings are discussed, emphasising the importance of access to PPE as well as peer and team-based support in alleviating the negative impact that COVID-19 has on HSCW's mental wellbeing. The results of this study also highlight the urgency of offering psychological input for HSCWs who need it. The importance of supportive, adaptive and visible leadership is highlighted. Cogan N 1 , MacIntyre G University of Strathclyde , Kennedy C University of Strathclyde , Beck Z University of Strathclyde , McInnes L University of Strathclyde , Tanner G NHS Lanarkshire , Morton L University of Glasgow , Kolacz J Kinsey Institute 1 University Of Strathclyde, GLASGOW Lanarkshire, Scotlan

ENACT study : what has helped health and social care workers maintain their mental wellbeing during the COVID-19 pandemic?

A growing body of research has highlighted the adverse impact of COVID-19 stressors on health and social care workers’ (HSCWs) mental health. Complementing this work, we report on the psychosocial factors that have had both a positive and negative impact on the mental wellbeing of HSCWs during the third lockdown period in Scotland. Using a cross-sectional design, participants (n= 1364) completed an online survey providing quantitative data and free open-text responses. A multi-method approach to analysis was used. The majority of HSCWs were found to have low wellbeing scores, high levels of COVID-19 stress, worry, burnout and risk perception scores and almost half of HSCWs met the clinical cut off for acute stress (indicative of PTSD). HSCWs with higher scores on adaptive coping strategies and team resilience reported higher scores on mental wellbeing. HSCWs were significantly more likely to seek informal support for dealing with personal or emotional problems compared to formal supports. Barriers to formal help-seeking were identified including stigma and fear of the consequences of disclosure. HSCWs mostly valued peer support, workplace supports, visible leadership and teamwork in maintaining their mental wellbeing. Our findings illuminate the complexity of the effects of the COVID-19 pandemic on HSCWs’ wellbeing and will inform future intervention development seeking to increase positive adaptation and improve staff wellbeing. Addressing barriers to mental health help-seeking among HSCWs is essential. The implications emphasise the importance of lessons learned across health and social care contexts, planning and preparedness for future pandemics

Environmental factors associated with general practitioner consultations for allergic rhinitis in London, England: a retrospective time series analysis

Objectives: To identify key predictors of general practitioner (GP) consultations for allergic rhinitis (AR) using meteorological and environmental data. Design: A retrospective, time series analysis of GP consultations for AR. Setting: A large GP surveillance network of GP practices in the London area. Participants: The study population was all persons who presented to general practices in London that report to the Public Health England GP in-hours syndromic surveillance system during the study period (3 April 2012 to 11 August 2014). Primary measure: Consultations for AR (numbers of consultations). Results: During the study period there were 186 401 GP consultations for AR. High grass and nettle pollen counts (combined) were associated with the highest increases in consultations (for the category 216-270 grains/m3, relative risk (RR) 3.33, 95% CI 2.69 to 4.12) followed by high tree (oak, birch and plane combined) pollen counts (for the category 260–325 grains/m3, RR 1.69, 95% CI 1.32 to 2.15) and average daily temperatures between 15°C and 20°C (RR 1.47, 95% CI 1.20 to 1.81). Higher levels of nitrogen dioxide (NO2) appeared to be associated with increased consultations (for the category 70–85 µg/m3, RR 1.33, 95% CI 1.03 to 1.71), but a significant effect was not found with ozone. Higher daily rainfall was associated with fewer consultations (15–20 mm/day; RR 0.812, 95% CI 0.674 to 0.980). Conclusions: Changes in grass, nettle or tree pollen counts, temperatures between 15°C and 20°C, and (to a lesser extent) NO2 concentrations were found to be associated with increased consultations for AR. Rainfall has a negative effect. In the context of climate change and continued exposures to environmental air pollution, intelligent use of these data will aid targeting public health messages and plan healthcare demand