Stewart J. Laing

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PURPOSE To determine the effect of a 48-h period of either fluid restriction (FR), energy restriction (ER), or fluid and energy restriction (F + ER) on 30-min treadmill time trial (TT) performance in temperate conditions. METHODS Thirteen males participated in four randomized 48-h trials (mean +/- SD: age, 21 +/- 3 yr; VO2max 50.9 +/- 4.3 mL x kg(-1) x(More)
PURPOSE Firstly, to identify whether saliva flow rate, osmolality, and total protein are potential markers of hydration, we compared changes in these parameters with changes in plasma osmolality during progressive dehydration. Secondly, we compared the sensitivity of saliva parameters to track hydration changes with the sensitivity of urine osmolality.(More)
The aim was to test the hypothesis that one night of sleep deprivation will impair pre-loaded 30 min endurance performance and alter the cardio-respiratory, thermoregulatory and perceptual responses to exercise. Eleven males completed two randomised trials separated by 7 days: once after normal sleep (496 (18) min: CON) and once following 30 h without sleep(More)
The purpose of this study was to investigate the effects of prolonged exercise with and without a thermal clamp on neutrophil trafficking, bacterial-stimulated neutrophil degranulation, stress hormones, and cytokine responses. Thirteen healthy male volunteers (means +/- SE: age 21 +/- 1 yr; mass 74.9 +/- 2.1 kg; maximal oxygen uptake 58 +/- 1 ml x kg(-1) x(More)
The aim was to investigate the effects of a 48 h period of fluid, energy or combined fluid and energy restriction on salivary IgA (s-IgA) responses at rest and after exercise. Thirteen healthy males (age 21 (sem 1) years) participated in four randomised 48 h trials. In the control trial participants received their estimated energy (12,154 (sem 230) kJ/d)(More)
INTRODUCTION Evidence supports an interaction between neuro-endocrine responses to exercise and immune responses to exercise. We hypothesized that prolonged exercise in the heat would evoke a greater stress hormone response and a greater decrease in neutrophil degranulation [lipopolysaccharide (LPS)-stimulated elastase release] than when the same exercise(More)
The aim of this study was to determine the effects of prolonged exercise in hot conditions on saliva IgA (s-IgA) responses in trained cyclists. On two occasions, in random order and separated by 1 week, 12 male cyclists cycled for 2 h on a stationary ergometer at 62 (3)% V̇O2 max [194 (4) W; mean (SEM)], on one occasion (HOT: 30.3°C, 76% RH) and on another(More)
A one night period without sleep is not uncommon amongst athletes travelling across time zones and military personnel during training and operations. However, the effect of one night without sleep on immune indices in response to strenuous exercise remains unknown. The objective was to determine the effect of one night without sleep on immune indices in(More)
PURPOSE It has been suggested that, because of the low sitting position in short-track speed skating, muscle blood flow is restricted, leading to decreases in tissue oxygenation. Therefore, wearable wireless-enabled near-infrared spectroscopy (NIRS) technology was used to monitor changes in quadriceps muscle blood volume and oxygenation during a 500-m race(More)
Wearable, wireless near-infrared (NIR) spectrometers were used to compare changes in on-ice short-track skating race simulations over 1,500 m with a 3-min cycle ergometry test at constant power output (400 W). The subjects were six male elite short-track speed skaters. Both protocols elicited a rapid desaturation (∆TSI%) in the muscle during early stages(More)