The effects of exercise on non-motor experiences of daily living experienced in Parkinson's Disease: A systematic review and network meta-analysis.

Introduction: Whilst non-motor experiences of daily living (NMeDL) reduce quality of life (QoL) in people with Parkinson's Disease (PD), research dedicated to NMeDL is lacking compared to motor symptoms. The aim of this Network Meta-Analysis (NMA) was to compare and determine the effects of exercise and dual-task training interventions on NMeDL for people with early-to-mid stage PD. Methods: Eight electronic databases were systematically searched, identifying randomised control trials (RCTs) that assessed the effect of interventions on the Movement Disease Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS); Part I scores. A fixed-effect pairwise and NMA were completed and confidence in estimates were assessed using the Confidence in Network Meta-Analysis (CINeMA) framework. Results: Five RCTs involving exercise were identified, involving 218 participants. No dual-tasking studies were suitable. Pairwise comparisons favoured tango and mixed-treadmill training (TT) when compared to control, however 95% Confidence Intervals (CI) crossed the line of no effect (MD = 0). Indirect comparisons revealed tango had clinically meaningful reductions in Part I scores compared to speed-TT and body-weight resistance training, (MD -4.47; 95% CI -8.50 to -0.44 and MD -4.38; 95% CI -7.86 to -0.90), indicating improved NMeDL. Compared to control, low confidence evidence suggests tango and mixed-TT improves NMeDL. Conclusions: Tango and mixed-TT are the most effective exercise interventions for improving NMeDL. Adoption of an exercise program in the early stages of PD, irrespective of modality, may be effective and holds potential clinical importance immediately following a diagnosis of PD.Other: Prospero Registration Number; CRD42022322470.

Sleep restriction between consecutive days of exercise impairs sprint and endurance cycling performance.

The study aim was to determine the effect of sleep restriction (3 h) between consecutive days of exercise on sprint and endurance cycling performance, wellness, and mood. A total of 10 well-trained males performed 2 consecutive-day trials separated by a normal night sleep (control [CONT]; mean [SD] sleep duration 3.0 [0.2] h) or sleep restriction (RES; mean [SD] sleep duration 3.0 [0.2] h). Experimental trials included a 90-min fixed-paced cycling bout and the respective sleep conditions on Day 1, followed by two 6-s peak power (6-s PP) tests, a 4- and 20-min time trial (TT) on Day 2. Profile of Mood States (POMS) and wellness questionnaires were recorded on Day 1 and Day 2. Blood lactate and glucose, heart rate (HR), and rating of perceived exertion were recorded throughout Day 2. Power output (PO) was significantly reduced for RES in the 6-s PP trial (mean [SD] 1159 [127] W for RES versus 1250 [186] W for CONT; p = 0.04) and mean PO during the 20-min TT (mean [SD] 237 [59] W for RES versus 255 [58] W for CONT; p = 0.03). There were no differences for HR, lactate and glucose, or POMS between CONT and RES in all experimental trials (p = 0.05-0.89). Participants reported a reduction in overall wellness prior to exercise on Day 2 following RES (mean [SD] 14.5 [1.6] au) compared to CONT (mean [SD] 16 [3.0] au; p = 0.034). Sleep restriction and the associated reductions in wellness, reduce cycling performance during consecutive days of exercise in a range of cycling tests that are relevant to both track and road cyclists.

Metabolic and inflammatory health in SARS-CoV-2 and the potential role for habitual exercise in reducing disease severity.

INTRODUCTION: The rapid emergence and spread of SARS-CoV-2 in late 2019 has infected millions of people worldwide with significant morbidity and mortality with various responses from health authorities to limit the spread of the virus. Although population-wide inoculation is preferred, currently, there is large variation and disparity in the acquisition, development, and deployment of vaccination programs in many countries. Even with availability of a vaccine, achieving herd immunity does not guarantee against reinfection from SARS-CoV-2. Emerging evidence indicates that vaccines do not eliminate infection but protect against severe disease and potential hospitalisation. Therefore, additional strategies which strengthen the immune system should be strongly considered to assist in reducing the overall health care burden and stem the rate of infection. There is now substantial evidence that SARS-CoV-2 disease severity and death are linked to existing comorbidities such as cardiovascular disease, obesity, and metabolic disorders. PURPOSE: In this review, we discuss the potential medium-to-long-term strategy of habitual exercise and its relationship to targeted comorbidities and underlying inflammation as a protective mechanism against SARS-CoV-2 disease severity. CONCLUSION: We conclude that engagement in habitual physical activity and exercise could be a strategy to mitigate the development of comorbidities and improve the response of the immune system, potentially reducing the risk of symptoms and life-threatening complications if infected.

Inflammatory Status and Cardio-metabolic Risk Stratification of Rotational Shift Work.

OBJECTIVES: To investigate the physiological effects of rotational shift work on measures of cardio-metabolic function. METHODS: Sedentary, healthy men (n = 87; age 37 ± 9 years; body mass index: 30.7 ± 5.1 kg m2) were recruited and categorized via occupation. SHIFT group: currently employed in rotational shift work defined by 8-12 h morning, afternoon, and night rotations; or NSHIFT: working fixed daytime hours. Testing procedures included baseline objective sleep assessment and laboratory testing, conducted between 0600 and 0900 h to assess body composition, cardiorespiratory fitness (VO2peak), inflammatory status [C-reactive protein, interleukin (IL)-6, and tumour necrosis factor-alpha (TNF-α)], glucose metabolism, heart rate variability (HRV), and self-reported leisure time physical activity (PA). RESULTS: SHIFT reported significantly less leisure time PA (P = 0.019), reduced VO2peak (P = 0.007), higher body fat percentage (BF%) (P = 0.021), increase response time to oral glucose tolerance test (P = 0.016), and higher IL-6 values (P = 0.008) compared with NSHIFT. A significant difference was observed in actigraphy measured total sleep time, with SHIFT recording reduced sleep following a night shift (P = 0.001). No group difference was observed in HRV or average sleep parameters (P > 0.05). Linear regression identified a significant association between occupation and inflammatory status (P = 0.006). CONCLUSIONS: Rotational shift work is associated with increased risk factors for cardio-metabolic disorders, despite no differences in sleep quality and quantity. The results suggest rotational shift work has a detrimental effect on the health and wellbeing of employees; with homeostatic desynchronization identified as potential pathogenic mechanisms.

Associations between exercise, inflammation and symptom severity in those with mental health disorders.

AIM: This study aimed to investigate the effects of 6-weeks of moderate intensity aerobic exercise on markers of inflammation and symptom severity in those undergoing management of a mental health disorder. METHOD: Twenty six participants were allocated into two groups, those reporting as apparently healthy (AH, n = 13) or those undergoing the management of a mental health disorder (MI, n = 13). Following a baseline testing and familiarization session, participants commenced the 6-week aerobic training intervention, involving stationary cycling at 65% heart rate reserve for 35 min progressing to 70% for 40 min. Measures of aerobic fitness (VO2peak), anthropometric variables, symptom questionnaires and venous blood were collect pre- and post-intervention. Venous blood was assessed for nod-like receptor pyrin containing-3, interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), IL-1ß, C-reactive protein (CRP) and brain-derived neurotropic factor (BDNF). RESULTS: There were no baseline differences between groups, however following the intervention the AH demonstrated lower TNF-α (p = 0.049) than the MI group. Within change was observed for the MI group with an increase in VO2peak (p = 0.049) and declines in symptom severity (p = 0.00-0.005). Significant correlations between variables indicated a positive association between body fat, body fat percentage, CRP and symptom severity (p = 0.01-0.04). Conversely, symptom severity and CRP were inversely associated with VO2peak values (p = 0.02-0.04). CONCLUSION: Six-weeks of moderate intensity aerobic exercise increases VO2peak and reduces symptom severity in those currently undergoing management of a mental health disorder. Further, there may be a physiological link between aerobic capacity, symptom severity, inflammation and adiposity, however greater exploration is required.

A preliminary investigation of the effects of short-duration, vigorous exercise following sleep restriction, fragmentation and extension on appetite and mood in inactive, middle-aged men.

This preliminary study aimed to investigate the effect of exercise on appetite and mood following multiple days of sleep disruption (restriction [RES], fragmentation [FRAG]) or sleep extension (EXT), compared to normal sleep (CONT) in inactive, middle-aged men. Nine men completed four randomised trials initiated by 3 nights (day 1-3) of CONT (6.5-8 hr), RES (4 hr), FRAG (6.5-8 hr, interrupted at 2-hr intervals) or EXT (10 hr). On day 4 between 08:30 and 11:00 hours, perceived appetite, food cravings, appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine-tyrosine [PYY]total ), glucose, mood states and wellness (stress, fatigue, soreness, and mood) were assessed before (post-sleep manipulation [SM]) and after (post-exercise [EX]) a 20-min vigorous cycling bout (rating of perceived exertion: 15). There was no effect of sleep manipulation or exercise on perceived appetite (p = .34-.62). Some aspects of food craving were altered after RES and EXT, with vigorous exercise attenuating the desire for sweet foods in RES (p = .12). PYYtotal was lower after RES compared to EXT and FRAG (p = .03), but was unaltered by exercise (p = .03). Ghrelin was higher for RES and EXT compared to CONT and FRAG after exercise (p = .001-.03). Total wellness was reduced and total mood disturbance (TMD) was higher after RES and FRAG compared to CONT and EXT (p ≤ .05). However, vigorous exercise countered these changes, with wellness and TMD remaining significantly impaired for FRAG compared to EXT only at this time (p = .02-.03). Vigorous exercise mitigates some aspects of food cravings and counters the impaired mood states that exist after multiple days of restricted and fragmented sleep.

Foam Rolling as a Recovery Tool Following Eccentric Exercise: Potential Mechanisms Underpinning Changes in Jump Performance.

PURPOSE: Recovery from exercise-induced muscle damage (EIMD) is paramount in sports performance. Foam rolling (FR) has been suggested to improve acute performance; however, the ability to facilitate recovery from eccentric (ECC) exercise remains unclear. METHODS: Eleven males undertook 6 × 25 ECC knee extensions to induce muscular damage. Immediately, 24, 48, and 72 h post-training countermovement jump (CMJ), maximal voluntary isometric contraction (MVIC), pressure-pain threshold (PPT), knee flexion range of motion (ROM), and mid-thigh circumference (MTC) were assessed. Neurophysiological measures included voluntary activation (VA), peak twitch torque (PTT), time to peak twitch (PTTtime), and rate of twitch torque development (RTD). Participants then spent 15 min FR prior to each time point or control (CON). Repeated measures analysis of variance (ANOVA) and standardized effect sizes (Hedges' g) ± 95% confidence intervals (95% CI) were used to compare FR and CON. RESULTS: CMJ was greater for FR compared to CON (P = 0.030) at 72 h (8.6%, P = 0.004) with moderate effects observed at 48 and 72 h (g = 0.54-0.66). PPT was greater with FR (P = 0.018) at 48 h only (23.7%, P = 0.013), with moderate to large effects noted at all-time points (g = 0.55-0.98). No significant differences were reported for MVIC (P = 0.777, -5.1 to 4.2%), ROM (P = 0.432, 1.6-3.5%), VA (P = 0.050, 3.6-26.2%), PTT (P = 0.302, -3.9 to 9.9%), PTTtime (P = 0.702, -24.4 to 23.5%), RTD (P = 0.864, -16.0 to -1.0%), or MTC (P = 0.409, -0.5 to -0.1%) between conditions. CONCLUSION: FR appears to improve jump performance in the later stages of recovery following ECC exercise. This may be in part due to improved pain tolerance; however, mechanical and neurophysiological are not modulated with FR.

Evening high-intensity interval exercise does not disrupt sleep or alter energy intake despite changes in acylated ghrelin in middle-aged men.

NEW FINDINGS: What is the central question of this study? What are the interactions between sleep and appetite following early evening high-intensity interval exercise (HIIE)? What is the main finding and its importance? HIIE can be performed in the early evening without subsequent sleep disruptions and may favourably alter appetite-related hormone concentrations. Nonetheless, perceived appetite and energy intake do not change with acute HIIE regardless of time of day. ABSTRACT: Despite exercise benefits for sleep and appetite, due to increased time restraints, many adults remain inactive. Methods to improve exercise compliance include preferential time-of-day or engaging in short-duration, high-intensity interval exercise (HIIE). Hence, this study aimed to compare effects of HIIE time-of-day on sleep and appetite. Eleven inactive men undertook sleep monitoring to determine baseline (BASE) sleep stages and exclude sleep disorders. On separate days, participants completed 30 min HIIE (60 s work at 100% V̇O2peak , 240 s rest at 50% V̇O2peak ) in (1) the morning (MORN; 06.00-07.00 h), (2) the afternoon (AFT; 14.00-16.00 h) and (3) the early evening (EVEN: 19.00-20.00 h). Measures included appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine tyrosine) and glucose pre-exercise, 30 min post-exercise and the next morning; overnight polysomnography (PSG; sleep stages); and actigraphy, self-reported sleep and food diaries for 48 h post-exercise. There were no between-trial differences for total sleep time (P = 0.46). Greater stage N3 sleep was recorded for MORN (23 ± 7%) compared to BASE (18 ± 7%; P = 0.02); however, no between-trial differences existed (P > 0.05). Rapid eye movement (REM) sleep was lower and non-REM sleep was higher for EVEN compared to BASE (P ≤ 0.05). At 30 min post-exercise, ghrelin was higher for AFT compared to MORN and EVEN (P = 0.01), while glucose was higher for MORN compared to AFT and EVEN (P ≤ 0.02). No between-trial differences were observed for perceived appetite (P ≥ 0.21) or energy intake (P = 0.57). Early evening HIIE can be performed without subsequent sleep disruptions and reduces acylated ghrelin. However, perceived appetite and energy intake appear to be unaffected by HIIE time of day.

Deception of cycling distance on pacing strategies, perceptual responses, and neural activity.

Pacing during exercise performance is well-established; however, little is known about the neural responses associated with changes in power output and the effect of exercise end-point knowledge. Therefore, the aim of this study was to examine the effect of deception of cycling distance on pacing, cerebral oxy- (O2Hb) and deoxy-haemoglobin concentrations, and alpha (α) wave activity. Ten well-trained male cyclists (23.7 ± 6.6 years) completed three cycling time trials (TT) on a stationary air-braked cycle ergometer and were informed the study was to examine the reliability of 3 × 30-km TT. Participants unknowingly completed three distances (24, 30, and 36 km) in a randomised order. Performance (power output; PO), physiological (heart rate; HR), perceptual (rating of perceived exertion; RPE), and neurological (O2Hb, HHb, and α activity) measures were recorded throughout each TT. Data were converted to a percentage relative to the total distance covered. At 100% completion, HR and PO were lower during the 36 km compared to the 30 km trial (P ≤ 0.01). Compared to the 24 km trial, α waves were reduced at 100% (effect size; ES = 1.01), while O2Hb was greater at 70% of completion in the 36 km trial (ES = 1.39). RPE was also higher for 36 km compared to 30-km trial at 80% and the 24-km trial at 10% and 40-100% of completion (P ≤ 0.02). We conclude that the increase in O2Hb and RPE during the 36-km trial, while a reduction in HR and PO is present, may indicate that the pre-frontal cortex may influence the regulation of exercise performance when deceived of the duration end-point by increasing perception of effort to reduce premature onset of physiological strain.

High-intensity interval exercise induces greater acute changes in sleep, appetite-related hormones, and free-living energy intake than does moderate-intensity continuous exercise.

The aim of this study was to compare the effect of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on sleep characteristics, appetite-related hormones, and eating behaviour. Eleven overweight, inactive men completed 2 consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400-1600 h), participants completed a 30-min exercise bout: either (i) MICE (60% peak oxygen consumption) or (ii) HIIE (60 s of work at 100% peak oxygen consumption: 240 s of rest at 50% peak oxygen consumption), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, and peptide tyrosine tyrosine) and glucose before exercise, 30 min after exercise, and the next morning after exercise; PSG sleep stages; and actigraphy (sleep quantity and quality); in addition, self-reported sleep and food diaries were recorded until 48 h after exercise. There were no between-trial differences for time in bed (p = 0.19) or total sleep time (p = 0.99). After HIIE, stage N3 sleep was greater (21% ± 7%) compared with BASE (18% ± 7%; p = 0.02). In addition, the number of arousals during rapid eye movement sleep were lower after HIIE (7 ± 5) compared with BASE (11 ± 7; p = 0.05). Wake after sleep onset was lower following MICE (41 min) compared with BASE (56 min; p = 0.02). Acylated ghrelin was lower and glucose was higher at 30 min after HIIE when compared with MICE (p ≤ 0.05). There were no significant differences between conditions in terms of total energy intake (p ≥ 0.05). HIIE appears to be more beneficial than MICE for improving sleep quality and inducing favourable transient changes in appetite-related hormones in overweight, inactive men. However, energy intake was not altered regardless of exercise intensity.

Sleep characteristics, sources of perceived stress and coping strategies in adolescent athletes.

The aim of the study was to examine sleep characteristics, scheduling of activities, perceived stress and coping strategies between periods of perceived high and low scheduling commitments in adolescent athletes. Twenty adolescents (10 male and 10 female) wore an Actiwatch during two 14-day testing periods, one in in January (JAN), which was deemed to be a period of low school and sport commitments, and one in March (MAR), during which there was a high volume of school and sport commitments. Actiwatches and sleep diaries assessed sleep quantity and quality, a daily schedule of all activities in 30-min increments was recorded and questionnaires related to perceived stress and coping strategies were administered. Time in bed and asleep, latency, efficiency and number of awakenings were not different between JAN and MAR (p > 0.05). Sleep durations were lower than their age-related recommendations (JAN 449 ± 47 min versus MAR 437 ± 31 min). Examination of differences between sexes showed shorter latency and higher sleep efficiency in female participants compared with male participants. Participants spent more time at school, completing homework, and travelling to and competing in sport, with reduced time spent on resting, social activities, physical activity and meal times during MAR compared with JAN (p < 0.05). Finally, stress levels were significantly increased during MAR compared with JAN, with no difference between sexes (p < 0.05). Adolescent athletes not attaining sufficient sleep quantity or quality during periods of low and high school and sport commitments, are experiencing increased perceived stress during these busy times but are using a wider range of coping strategies during this time.

The influence of knowledge of performance endpoint on pacing strategies, perception of effort, and neural activity during 30-km cycling time trials.

It is understood that withholding information during exercise can alter performance during self-paced exercise, though less is known about neural activity during such exercise. The aim of this study was to compare the effects of withholding versus providing distance feedback on perception, muscular activation, and cerebral activity during cycling time trials (TT). Nine well-trained male cyclists randomly completed 2 x 30-km TT, with provision of performance information and distance feedback (known; KTT), and without performance information and remaining distance (unknown; UTT). Prefrontal cortex (PFC) hemoglobin concentration, electroencephalogy (EEG) responses of the parietal lobe (PL) and motor cortex (MC), and surface electromyogram (EMG) of the right thigh were monitored throughout the TTs, in addition to heart rate (HR), rating of perceived exertion (RPE), and power output (PO). Time to completion was shorter for the KTT compared to UTT (51.04 ± 3.26 vs. 49.25 ± 3.57 min, P = 0.01). There were no differences evident for RPE between conditions (P > 0.50). However, during the final 2 km, the KTT presented higher PO (P ≤ 0.05), HR (P = 0.03) and MC, and PL EEG activity (d = 0.51-0.71) in addition to increased tissue hemoglobin index (nTHI) and oxygen extraction (HHb) (d = 0.55-0.65) compared to the UTT. In conclusion, when withholding information pertaining to remaining distance, performance was reduced due to the application of a conservative pacing strategy. In addition, the increase in HHb across the PFC was strongly correlated with PO (r = 0.790; P < 0.001) suggesting knowledge about remaining distance may increase activation across the PFC. Further, it appears that changes within the PFC may play a role in the regulation of cycling performance.

Sleep quantity and quality during consecutive day heat training with the inclusion of cold-water immersion recovery.

Exercise in the heat is a common occurrence among athletes and often is intentional in order to gain heat acclimation benefits, however, little is known about how such training may affect sleep. Therefore, this study investigated five days of training in the heat of varying intensity and duration and inclusion of cold-water immersion (CWI) recovery on sleep quantity and quality. Thirty recreationally-trained male participants completed five days of heat training (HT) and were randomised into three interventions including (i) 90 min cycling at 40% power at maximal aerobic capacity (Pmax) with 15 min passive recovery (90HT); (ii) 90 min cycling at 40% Pmax with 15 min CWI recovery (90CWI); or (iii) 30 min cycling alternating between 40% and 70% Pmax, with 15 min passive recovery (30HT). Sleep quality and quantity were assessed using Actigraphy and sleep diaries during five baseline nights (BASE) and five nights of HT which included subjective sleep quality and objective assessments of sleep quantity and quality. Total time asleep and perceived sleep quality were reduced, while awake duration and wake after sleep onset (WASO) were increased (p = 0.001-0.01) during HT compared to BASE. Latency was shorter for 30HT compared to 90HT during HT (p = 0.02), however, no differences between interventions for all other sleep variables (p > 0.05). The reduction in total sleep time due to increases in average wake duration during HT may be due to the unaccustomed increased in training frequency. Of note, reducing training in the heat duration per day improved sleep latency and sleep quality with no effect on total sleep time, while the addition of CWI has minimal effect on sleep quality or quantity.

Effects of consecutive days of match play on technical performance in tennis.

Elite tennis is characterised by repeated bouts of up to 5-set match play, yet little is known about the technical requirements of shots played. This study therefore investigated technical performance changes over consecutive days of prolonged, simulated tennis match play. A total of 7 well-trained men tennis players performed 4 consecutive days of competitive 4-h match play. Matches were notated to determine between-day changes in groundstroke and serve performance, as well as point and match durations. Changes ≥75% likely to exceed the smallest important effect size (0.2) were considered meaningful and represented as effect size ± 90% confidence interval. Effective playing time reduced on days 3 and 4, alongside likely increases in "stretch" groundstrokes over the 4 days (mean effect size ± 90% confidence interval; 0.57 ± 0.38) and "stretch" backhand returns on days 2 and 3 (0.39 ± 0.54 and 0.67 ± 0.55). Relative unforced errors increased on day 4 (vs. day 2; 0.36 ± 0.22) and second-serve winning percentage reduced after day 1 (-0.47 ± 0.50). Further, a likely increase in emotional outbursts characterised day 3 (vs. day 2; 0.73 ± 0.57). Consecutive-day match play impairs hitting accuracy, stroke positioning and emotional responses; an understanding of which prepares players for elite-standard tennis tournament play.

The effect of high versus low intensity heat acclimation on performance and neuromuscular responses.

This study examined the effect of exercise intensity and duration during 5-day heat acclimation (HA) on cycling performance and neuromuscular responses. 20 recreationally trained males completed a 'baseline' trial followed by 5 consecutive days HA, and a 'post-acclimation' trial. Baseline and post-acclimation trials consisted of maximal voluntary contractions (MVC), a single and repeated countermovement jump protocol, 20km cycling time trial (TT) and 5×6s maximal sprints (SPR). Cycling trials were undertaken in 33.0 ± 0.8°C and 60 ± 3% relative humidity. Core (Tcore), and skin temperatures (Tskin), heart rate (HR), rating of perceived exertion (RPE) and thermal sensation were recorded throughout cycling trials. Participants were assigned to either 30min high-intensity (30HI) or 90min low-intensity (90LI) cohorts for HA, conducted in environmental conditions of 32.0 ± 1.6°C. Percentage change time to complete the 20km TT for the 90LI cohort was significantly improved post-acclimation (-5.9 ± 7.0%; P=0.04) compared to the 30HI cohort (-0.18 ± 3.9%; P<0.05). The 30HI cohort showed greatest improvements in power output (PO) during post-acclimation SPR 1 and 2 compared to 90LI (546 ± 128W and 517 ± 87W, respectively; P<0.02). No differences were evident for MVC within 30HI cohort, however, a reduced performance indicated by % change within the 90LI (P=0.04). Compared to baseline, mean Tcore was reduced post-acclimation within the 30HI cohort (P=0.05) while mean Tcore and HR were significantly reduced within the 90LI cohort (P=0.01 and 0.04, respectively). Greater physiological adaptations and performance improvements were noted within the 90LI cohort compared to the 30HI. However, 30HI did provide some benefit to anaerobic performance including sprint PO and MVC. These findings suggest specifying training duration and intensity during heat acclimation may be useful for specific post-acclimation performance.

The effect of overnight sleep deprivation after competitive rugby league matches on postmatch physiological and perceptual recovery.

PURPOSE: This study examined the effects of overnight sleep deprivation on recovery after competitive rugby league matches. METHODS: Eleven male amateur rugby league players played 2 competitive matches, followed by either a normal night's sleep (~8 h; CONT) or a sleep-deprived night (~0 h; SDEP) in a randomized fashion. Testing was conducted the morning of the match, immediately postmatch, 2 h postmatch, and the next morning (16 h postmatch). Measures included countermovement-jump (CMJ) distance, knee-extensor maximal voluntary contraction (MVC) and voluntary activation (VA), venous-blood creatine kinase (CK) and C-reactive protein (CRP), perceived muscle soreness, and a word-color recognition cognitive-function test. Percent change between postmatch and 16-h postmatch was reported to determine the effect of the intervention the next morning. RESULTS: Large effects indicated a greater postmatch to 16-h-postmatch percentage decline in CMJ distance after SDEP than in CONT (P = .10-.16, d = 0.95-1.05). Similarly, the percentage decline in incongruent word-color reaction times was increased in SDEP trials (P = .007, d = 1.75). Measures of MVC did not differ between conditions (P = .40-.75, d = 0.13-0.33), although trends for larger percentage decline in VA were detected in SDEP (P = .19, d = 0.84). Furthermore, large effects indicated higher CK and CRP responses 16 h postmatch in SDEP than in CONT (P = .11-.87, d = 0.80-0.88). CONCLUSIONS: Sleep deprivation negatively affected recovery after a rugby league match, specifically impairing CMJ distance and cognitive function. Practitioners should promote adequate postmatch sleep patterns or adjust training demands the next day to accommodate the altered physical and cognitive state after sleep deprivation.

The effect of post-match alcohol ingestion on recovery from competitive rugby league matches.

This study investigated the effects of alcohol ingestion on lower-body strength and power and physiological and cognitive recovery after competitive Rugby League matches. Nine male Rugby players participated in 2 matches, followed by 1 of 2 randomized interventions, a control or alcohol ingestion session. Four hours post-match, participants consumed either beverages containing a total of 1 g of ethanol per kilogram bodyweight (vodka and orange juice; ALC) or a caloric and taste-matched nonalcoholic beverage (orange juice; CONT). Before the match, immediately post-match, 2 hours post-, and 16 hours post-match measures of countermovement jump (CMJ); maximal voluntary contraction (MVC); voluntary activation (VA); and damage and stress markers of creatine kinase (CK), C-reactive protein (CRP), cortisol, and testosterone analyzed from venous blood collection; and cognitive function (modified Stroop test) were determined. Alcohol resulted in large effects for decreased CMJ height (-2.35 ± 8.14% and -10.53 ± 8.36% decrement for CONT and ALC, respectively; p = 0.15, d = 1.40), without changes in MVC (p = 0.52, d = 0.70) or VA (p = 0.15, d = 0.69). Furthermore, alcohol resulted in a significant slowing of total time in a cognitive test (p = 0.04, d = 1.59) while exhibiting large effects for detriments in congruent reaction time (p = 0.19, d = 1.73). Despite large effects for increased cortisol after alcohol ingestion during recovery (p = 0.28, d = 1.44), post-match alcohol consumption did not unduly affect testosterone (p = 0.96, d = 0.10), CK (p = 0.66, d = 0.70), or CRP (p = 0.75, d = 0.60). It seems that alcohol consumption during the evening after competitive rugby matches may have some detrimental effects on peak power and cognitive recovery the morning after a Rugby League match. Accordingly, practitioners should be aware of the potential associated detrimental effects of alcohol consumption on recovery and provide alcohol awareness to athletes at post-match functions.

Self-paced intermittent-sprint performance and pacing strategies following respective pre-cooling and heating.

This study examined the effects of pre-exercise cooling and heating on neuromuscular function, pacing and intermittent-sprint performance in the heat. Ten male, team sport athletes completed three randomized, counterbalanced conditions including a thermo-neutral environment (CONT), whole body submersion in an ice bath (ICE) and passive heating in a hot environment (HEAT) before 50 min of intermittent-sprint exercise (ISE) in the heat (31 + 1°C). Exercise involved repeated 15 m maximal sprints and self-paced exercise of varying intensities. Performance was measured by sprint times and distance covered during self-paced exercise. Maximal isometric contractions were performed to determine the maximal voluntary torque (MVT), activation (VA) and contractile properties. Physiological measures included heart rate (HR), core (T (core)) and skin (T (skin)) temperatures, capillary blood and perceptual ratings. Mean sprint times were slower during ICE compared to HEAT (P < 0.05). Total distance covered was not different between conditions, but less distance was covered during HEAT in 31-40 min compared to CONT, and 41-50 min compared to ICE (P < 0.05). MVT was reduced post-exercise compared to post-intervention in CONT and HEAT. VA was reduced post-intervention in HEAT compared to CONT and ICE, and post-exercise compared to ICE (P < 0.05). HR, T (core) and T (skin) during exercise were lower in ICE compared to CONT and HEAT (P < 0.05). Sprint times and distance covered were not affected by ICE and HEAT conditions compared to CONT. However, initial sprint performance was slowed by pre-cooling, with improvements following passive heating possibly due to altered contractile properties. Conversely, pre-cooling improved exercise intensities, whilst HEAT resulted in greater declines in muscle recruitment and ensuing distance covered.

Post-match changes in neuromuscular function and the relationship to match demands in amateur rugby league matches.

OBJECTIVES: The current study investigated the change in neuromuscular contractile properties following competitive rugby league matches and the relationship with physical match demands. DESIGN: Eleven trained, male rugby league players participated in 2-3 amateur, competitive matches (n = 30). METHODS: Prior to, immediately (within 15-min) and 2h post-match, players performed repeated counter-movement jumps (CMJ) followed by isometric tests on the right knee extensors for maximal voluntary contraction (MVC), voluntary activation (VA) and evoked twitch contractile properties of peak twitch force (Pt), rate of torque development (RTD), contraction duration (CD) and relaxation rate (RR). During each match, players wore 1 Hz Global Positioning Satellite devices to record distance and speeds of matches. Further, matches were filmed and underwent notational analysis for number of total body collisions. RESULTS: Total, high-intensity, very-high intensity distances covered and mean speed were 5585 ± 1078 m, 661 ± 265, 216 ± 121 m and 75 ± 14 m min(-1), respectively. MVC was significantly reduced immediately and 2h post-match by 8 ± 11 and 12 ± 13% from pre-match (p<0.05). Moreover, twitch contractile properties indicated a suppression of Pt, RTD and RR immediately post-match (p<0.05). However, VA was not significantly altered from pre-match (90 ± 9%), immediately-post (89 ± 9%) or 2h post (89 ± 8%), (p>0.05). Correlation analyses indicated that total playing time (r = -0.50) and mean speed (r = -0.40) were moderately associated to the change in post-match MVC, while mean speed (r = 0.35) was moderately associated to VA. CONCLUSIONS: The present study highlights the physical demands of competitive amateur rugby league result in interruption of peripheral contractile function, and post-match voluntary torque suppression may be associated with match playing time and mean speeds.