This project started in September 2022 and finished in 2025 and was directed by Dr Ben J Edwards and led by Dr Chloe Gallagher aimed to address “Effects of acute sleep restriction on performance with napping interventions and sleep measurement considerations”.
This work assessed the current state of the art in the literature regarding relation to acute sleep restriction and the effects on exercise performance, in addition to time-of-day effects on cognitive function and perceptual responses. The review highlighted methodological considerations that heavily influence sleep yet are not routinely employed in research studies, which may explain the mixed outcomes.
The laboratory-based research investigated the effectiveness of naps, with consideration for timing and duration of the nap session. Dr Chloe Gallagher demonstrated that implementing a post lunch nap did not improve afternoon maximal and submaximal performance compared to no nap following acute sleep restriction. However, nap interventions may benefit cognitive function and perceptual responses by alleviating the accumulation of homeostatic pressure, reducing excessive fatigue and restoring alertness.
To provide practical recommendations research exploring the validity of consumer sleep devices and research grade actigraphy compared to polysomnography in the laboratory versus the home setting. Practically, the findings suggest that consumer devices are not ready for use in research or clinical settings due to substantial inaccuracies with polysomnography, hence consumers should exercise caution when using these devices.
Dr Edwards has led projects investigating effects of sleep deprivation on cognitive and sporting and physiological performance, investigating interventions such as naps or dietary (Zinc or Magnesium). So far, the groups work has informed policy implementation in sport as well as informing working populations undertaking shift worker.
Information by the group has led to a recent narrative review and 2021 expert consensus recommendations by Prof Neil Walsh and Dr Edwards in the British Journal of Sports Medicine. As well as book chapters in on Athletic Performance; Effects of Sleep Loss. In “The Encyclopedia of Sleep”.
This 5-year Ministry of Defence (MOD) funded research programme, led by Prof. Neil Walsh, investigates the risk factors for heat illness and the long-term effects of early life adversity on health and performance. The programme, which commenced in 2020, is supported by £1.43 million in funding, including £1.28 million awarded to Liverpool John Moores University.
A major focus of the research has been understanding why some military personnel are more susceptible to exertional heat illness, a potentially fatal condition that remains a significant concern for defence organisations worldwide. Through a series of epidemiological and applied studies, the programme has identified novel risk factors that influence an individual's vulnerability to heat-related illness during military training and operations.
One of the programme's most important findings demonstrated that exercising while experiencing symptoms of a respiratory infection increases the risk of severe heat illness by approximately four-fold. This evidence directly informed updates to UK Defence policy, underpinning the introduction of a new "no-fault opt-out" policy that allows military recruits to withdraw from training activities when unwell without penalty. The findings have been incorporated into official MOD guidance and represent a significant advancement in the prevention of serious heat-related illness.
Collectively, this research has improved understanding of the biological, environmental, and behavioural factors contributing to heat illness risk, while delivering tangible impact beyond academia through evidence-based changes to military policy and practice. The programme continues to generate insights that support the health, safety, and operational effectiveness of military personnel.
This project, funded by Danone Research and Innovation and led by Professor Neil Walsh, investigated the relationship between hydration status and the body's physiological response to psychological stress.
The programme of research examined whether mild dehydration, a common but often overlooked condition in everyday life, could influence the way individuals respond to acute stressors. Using controlled experimental designs, participants underwent stress-inducing tasks while measures of hydration status, cardiovascular function, mood, and hormonal responses were assessed.
The findings demonstrated that even modest levels of dehydration amplified physiological stress responses, including greater increases in cortisol and cardiovascular strain, while also negatively affecting mood and subjective wellbeing. In contrast, maintaining adequate hydration appeared to attenuate these responses, suggesting that hydration status plays an important role in resilience to everyday psychological stress.
Collectively, this work provided novel evidence that hydration influences not only physical performance and health, but also the body's capacity to cope with psychological challenges. The findings have important implications for public health, occupational settings, and athletic populations, highlighting adequate hydration as a simple and accessible strategy to support wellbeing and stress management.
