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Zenk F, Willmott AGB, Fortin-Guichard D, Austick K, Mann DL, Winckler C, Allen PM. Profile of Athletes With a Vision Impairment: Exploring Demographics and Ocular Pathologies of Athletes in Three Paralympic Sports. Am J Phys Med Rehabil 2024; 103:172-180. [PMID: 37026871 DOI: 10.1097/phm.0000000000002255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
OBJECTIVE This study aimed to explore the profile of athletes with a vision impairment who compete in three Paralympic sports (goalball, vision impairment judo, and blind football). DESIGN Descriptive and association analyses of the vision impairment athletes' profile were conducted. RESULTS The typical athlete profile was a male (65.1%), aged 26-34 yrs (39.7%), from Europe (38.8%), representing a country with a high income (46.1%), and was diagnosed with a retinal-related ocular pathology (38.9%). In all three sports, the ages of the athletes were similar. In goalball, most athletes were from Europe, represented countries with a high income, and were diagnosed with retinal-, globe-, or neurological-related pathologies. In vision impairment judo, the majority of athletes were from Asia, represented countries with an upper middle income, and were diagnosed with retinal-, global-, or neurological-related pathologies. In blind football, most athletes were from Europe, represented countries with an upper middle income, and were diagnosed with retinal-, neurological-related ocular pathologies, or glaucoma. CONCLUSIONS The homogeneity of the athletes' profile suggests that an effort is needed to target other parts of the vision impairment population to take part in vision impairment sports. Differences in the athletes' profiles across the sports provide information that may be useful for sport-specific talent identification.
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Affiliation(s)
- Franziska Zenk
- From the Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, United Kingdom (FZ, KA, PMA); Cambridge Centre for Sport and Exercise Sciences (CCSES), School of Psychology and Sport Science, Anglia Ruskin University, Cambridge, United Kingdom (AGBW); Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences and Institute Brain and Behavior Amsterdam, Amsterdam, the Netherlands (DF-G, DLM); and Department of Human Movement Sciences, São Paulo Federal University, Santos, Brazil (CW)
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Willmott AGB, Diment AG, Chung HC, James CA, Maxwell NS, Roberts JD, Gibson OR. Cross-adaptation from heat stress to hypoxia: A systematic review and exploratory meta-analysis. J Therm Biol 2024; 120:103793. [PMID: 38471285 DOI: 10.1016/j.jtherbio.2024.103793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 01/03/2024] [Accepted: 01/12/2024] [Indexed: 03/14/2024]
Abstract
Cross-adaptation (CA) refers to the successful induction of physiological adaptation under one environmental stressor (e.g., heat), to enable subsequent benefit in another (e.g., hypoxia). This systematic review and exploratory meta-analysis investigated the effect of heat acclimation (HA) on physiological, perceptual and physical performance outcome measures during rest, and submaximal and maximal intensity exercise in hypoxia. Database searches in Scopus and MEDLINE were performed. Studies were included when they met the Population, Intervention, Comparison, and Outcome criteria, were of English-language, peer-reviewed, full-text original articles, using human participants. Risk of bias and study quality were assessed using the COnsensus based Standards for the selection of health status Measurement INstruments checklist. Nine studies were included, totalling 79 participants (100 % recreationally trained males). The most common method of HA included fixed-intensity exercise comprising 9 ± 3 sessions, 89 ± 24-min in duration and occurred within 39 ± 2 °C and 32 ± 13 % relative humidity. CA induced a moderate, beneficial effect on physiological measures at rest (oxygen saturation: g = 0.60) and during submaximal exercise (heart rate: g = -0.65, core temperature: g = -0.68 and skin temperature: g = -0.72). A small effect was found for ventilation (g = 0.24) and performance measures (peak power: g = 0.32 and time trial time: g = -0.43) during maximal intensity exercise. No effect was observed for perceptual outcome measures. CA may be appropriate for individuals, such as occupational or military workers, whose access to altitude exposure prior to undertaking submaximal activity in hypoxic conditions is restricted. Methodological variances exist within the current literature, and females and well-trained individuals have yet to be investigated. Future research should focus on these cohorts and explore the mechanistic underpinnings of CA.
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Affiliation(s)
- Ashley G B Willmott
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom; Environmental Extremes Laboratory, University of Brighton, Eastbourne, East Sussex, United Kingdom; Para-Monte Altitude Awareness Charity, Eastbourne, East Sussex, United Kingdom.
| | - Alicia G Diment
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom; Pulmonary Function Laboratory, Norfolk and Norwich University Hospital, Colney Lane, Norwich, Norfolk, United Kingdom.
| | - Henry C Chung
- School of Sport, Rehabilitation and Exercise Sciences (SRES), University of Essex, Colchester, Essex, United Kingdom.
| | - Carl A James
- Hong Kong Sports Institute, Sha Tin, Hong Kong, China; Department of Sport, Physical Education and Health, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, East Sussex, United Kingdom; Para-Monte Altitude Awareness Charity, Eastbourne, East Sussex, United Kingdom.
| | - Justin D Roberts
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom.
| | - Oliver R Gibson
- Centre for Physical Activity in Health and Disease (CPAHD), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, United Kingdom.
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Zenk F, Willmott AGB, Mann DL, Allen PM. Impact of Running With and Without a Guide on Short Distance Running Performance for Athletes With a Vision Impairment. Am J Phys Med Rehabil 2024; 103:74-78. [PMID: 36917042 DOI: 10.1097/phm.0000000000002218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
OBJECTIVE This study aimed to investigate the difference of running with or without a guide on running performance (100, 200, and 400 m) for athletes with a vision impairment. DESIGN Data including athletes' and guides' sex, age, and race times were extracted from 11 elite competitions. RESULTS Male athletes predominantly ran without a guide (100 m = 91.4%, 200 m = 88.1%, 400 m = 84.8%), whereas female athletes mainly ran with a guide (100 m = 60.5%, 200 m = 80.0%, 400 m = 72.0%). No significant difference in 100-m race times was found between male athletes with or without a guide ( P = 0.647). For the 200 m ( P = 0.001) and 400 m ( P = 0.030), race times were significantly slower for male athletes running with a guide (mean rank 200 m = 36.80, 400 m = 33.57) compared to without a guide (mean rank 200 m = 19.43, 400 m = 21.69). Conversely, 100- ( P = 0.015), 200- ( P = 0.025), and 400-m ( P = 0.029) race times were significantly faster for female athletes with (mean rank 100 m = 18.25, 200 m = 13.71, 400 m = 11.00) compared with without a guide (mean rank 100 m = 27.74, 200 m = 22.67, 400 m = 21.69). CONCLUSIONS Running with a guide affects vision impairment athletes' race times. The influence of running with a guide, and the gender mix of vision impairment athlete and guide, should be considered in any research with the aim of establishing a new classification system for vision impairment athletes.
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Affiliation(s)
- Franziska Zenk
- From the Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, United Kingdom (FZ, PMA); Cambridge Centre for Sport and Exercise Sciences (CCSES), School of Psychology and Sport Science, Anglia Ruskin University, Cambridge, United Kingdom (AGBW); and Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences and Institute Brain and Behavior Amsterdam, Amsterdam, the Netherlands (DLM)
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Willmott AGB, James CA, Hayes M, Maxwell NS, Roberts J, Gibson OR. The reliability of a portable steam sauna pod for the whole-body passive heating of humans. J Therm Biol 2023; 118:103743. [PMID: 37979477 DOI: 10.1016/j.jtherbio.2023.103743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 11/20/2023]
Abstract
INTRODUCTION Passive heating is receiving increasing attention within human performance and health contexts. A low-cost, portable steam sauna pod may offer an additional tool for those seeking to manipulate physiological (cardiovascular, thermoregulatory and sudomotor) and perceptual responses for improving sporting or health profiles. This study aimed to 1) report the different levels of heat stress and determine the pods' inter-unit reliability, and 2) quantify the reliability of physiological and perceptual responses to passive heating. METHOD In part 1, five pods were assessed for temperature and relative humidity (RH) every 5 min across 70 min of heating for each of the 9 settings. In part 2, twelve males (age: 24 ± 4 years) completed two 60 min trials of passive heating (3 × 20 min at 44 °C/99% RH, separated by 1 week). Heart rate (HR), rectal (Trectal) and tympanic temperature (Ttympanic) were recorded every 5 min, thermal comfort (Tcomfort) and sensation (Tsensation) every 10 min, mean arterial pressure (MAP) at each break period and sweat rate (SR) after exiting the pod. RESULTS In part 1, setting 9 provided the highest temperature (44.3 ± 0.2 °C) and longest time RH remained stable at 99% (51±7 min). Inter-unit reliability data demonstrated agreement between pods for settings 5-9 (intra-class correlation [ICC] >0.9), but not for settings 1-4 (ICC <0.9). In part 2, between-visits, high correlations, and low typical error of measurement (TEM) and coefficient of variation (CV) were found for Trectal, HR, MAP, SR, and Tcomfort, but not for Ttympanic or Tsensation. A peak Trectal of 38.09 ± 0.30 °C, HR of 124 ± 15 b min-1 and a sweat loss of 0.73 ± 0.33 L were reported. No between-visit differences (p > 0.05) were observed for Trectal, Ttympanic, Tsensation or Tcomfort, however HR (+3 b.min-1) and MAP (+4 mmHg) were greater in visit 1 vs. 2 (p < 0.05). CONCLUSION Portable steam sauna pods generate reliable heat stress between-units. The highest setting (44 °C/99% RH) also provides reliable but modest adjustments in physiological and perceptual responses.
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Affiliation(s)
- A G B Willmott
- Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, Cambridge, UK; Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.
| | - C A James
- Hong Kong Sports Institute (HKSI), Hong Kong; Department of Sport, Physical Education and Health, Hong Kong Baptist University. Kowloon Tong, Hong Kong
| | - M Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - N S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - J Roberts
- Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, Cambridge, UK
| | - O R Gibson
- Centre for Physical Activity in Health and Disease (CHPAD), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, UK
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James CA, Gibson OR, Dhawan A, Stewart CM, Willmott AGB. Volume and Intensity of Locomotor Activity in International Men's Field Hockey Matches Over a 2-Year Period. Front Sports Act Living 2021; 3:653364. [PMID: 34127962 PMCID: PMC8196230 DOI: 10.3389/fspor.2021.653364] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/31/2021] [Indexed: 11/27/2022] Open
Abstract
The locomotor demands of international men's field hockey matches were investigated across positions (DEF, MID, FWD) and playing quarters. Volume (i.e., total values) and intensity (i.e., relative to playing time) data were collected using 10-Hz GPS/100-Hz accelerometer units from the #11 world-ranked (WR) team, during 71 matches, against 24 opponents [WR 12 ± 11 (range, 1–60)]. Mean ± SD team total distance (TD) was 4,861 ± 871 m, with 25% (1,193 ± 329 m) “high-speed running” (>14.5 km h−1) and 8% (402 ± 144 m) “sprinting” (>19.0 km h−1). Reduced TD (range, −3 to 4%) and average speed (range, −3.4 to 4.7%) occurred through subsequent quarters, vs. Q1 (p < 0.05). A “large” negative relationship (r = −0.64) was found between playing duration and average speed. Positional differences (p < 0.05) were identified for all volume metrics including; playing duration (DEF, 45:50 ± 8:00 min; MID, 37:37 ± 7:12 min; FWD, 33:32 ± 6:22 min), TD (DEF, 5,223 ± 851 m; MID, 4,945 ± 827 m; FWD, 4,453 ± 741 m), sprinting distance (DEF, 315 ± 121 m; MID, 437 ± 144 m; FWD, 445 ± 129 m), and acceleration efforts (>2 m s−2; DEF, 48 ± 12; MID, 51 ± 11; FWD, 50 ± 14). Intensity variables similarly revealed positional differences (p < 0.05) but with a different pattern between positions; average speed (DEF, 115 ± 10 m min−1; MID, 132 ± 10 m min−1; FWD, 134 ± 15 m min−1), sprinting (DEF, 7 ± 3 m min−1; MID, 12 ± 4 m min−1; FWD, 14 ± 4 m min−1), and accelerations (DEF, 1.1 ± 0.3 n min−1; MID, 1.4 ± 0.2 n min−1; FWD, 1.5 ± 0.3 n min−1). Physical outputs reduced across playing quarters, despite unlimited substitutions, demonstrating the importance of optimizing physical preparation prior to international competition. Volume and intensity data highlight specific positional requirements, with forwards displaying shorter playing durations but greater high-intensity activities than defenders.
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Affiliation(s)
- Carl A James
- Sport Science Department, Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Oliver R Gibson
- Division of Sport, Health and Exercise Sciences, Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, United Kingdom
| | | | | | - Ashley G B Willmott
- Cambridge Center for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, United Kingdom
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Roberts JD, Willmott AGB, Beasley L, Boal M, Davies R, Martin L, Chichger H, Gautam L, Del Coso J. The Impact of Decaffeinated Green Tea Extract on Fat Oxidation, Body Composition and Cardio-Metabolic Health in Overweight, Recreationally Active Individuals. Nutrients 2021; 13:nu13030764. [PMID: 33652910 PMCID: PMC7996723 DOI: 10.3390/nu13030764] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/14/2021] [Accepted: 02/24/2021] [Indexed: 12/11/2022] Open
Abstract
This study investigated the effect of decaffeinated green tea extract (dGTE), with or without antioxidant nutrients, on fat oxidation, body composition and cardio-metabolic health measures in overweight individuals engaged in regular exercise. Twenty-seven participants (20 females, 7 males; body mass: 77.5 ± 10.5 kg; body mass index: 27.4 ± 3.0 kg·m2; peak oxygen uptake (V.O2peak): 30.2 ± 5.8 mL·kg−1·min−1) were randomly assigned, in a double-blinded manner, either: dGTE (400 mg·d−1 (−)-epigallocatechin−3-gallate (EGCG), n = 9); a novel dGTE+ (400 mg·d−1 EGCG, quercetin (50 mg·d−1) and α-lipoic acid (LA, 150 mg·d−1), n = 9); or placebo (PL, n = 9) for 8 weeks, whilst maintaining standardised, aerobic exercise. Fat oxidation (‘FATMAX’ and steady state exercise protocols), body composition, cardio-metabolic and blood measures (serum glucose, insulin, leptin, adiponectin, glycerol, free fatty acids, total cholesterol, high [HDL-c] and low-density lipoprotein cholesterol [LDL-c], triglycerides, liver enzymes and bilirubin) were assessed at baseline, week 4 and 8. Following 8 weeks of dGTE+, maximal fat oxidation (MFO) significantly improved from 154.4 ± 20.6 to 224.6 ± 23.2 mg·min−1 (p = 0.009), along with a 22.5% increase in the exercise intensity at which fat oxidation was deemed negligible (FATMIN; 67.6 ± 3.6% V.O2peak, p = 0.003). Steady state exercise substrate utilisation also improved for dGTE+ only, with respiratory exchange ratio reducing from 0.94 ± 0.01 at week 4, to 0.89 ± 0.01 at week 8 (p = 0.004). This corresponded with a significant increase in the contribution of fat to energy expenditure for dGTE+ from 21.0 ± 4.1% at week 4, to 34.6 ± 4.7% at week 8 (p = 0.006). LDL-c was also lower (normalised fold change of −0.09 ± 0.06) for dGTE+ by week 8 (p = 0.038). No other significant effects were found in any group. Eight weeks of dGTE+ improved MFO and substrate utilisation during exercise, and lowered LDL-c. However, body composition and cardio-metabolic markers in healthy, overweight individuals who maintained regular physical activity were largely unaffected by dGTE.
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Affiliation(s)
- Justin D. Roberts
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK; (A.G.B.W.); (M.B.); (R.D.); (L.M.)
- Correspondence: ; Tel.: +44-845-196-5154
| | - Ashley G. B. Willmott
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK; (A.G.B.W.); (M.B.); (R.D.); (L.M.)
| | - Liam Beasley
- Department for Health, University of Bath, Bath BA2 7AY, UK;
| | - Mariette Boal
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK; (A.G.B.W.); (M.B.); (R.D.); (L.M.)
| | - Rory Davies
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK; (A.G.B.W.); (M.B.); (R.D.); (L.M.)
| | - Laurence Martin
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge CB1 1PT, UK; (A.G.B.W.); (M.B.); (R.D.); (L.M.)
| | - Havovi Chichger
- School of Life Sciences, Anglia Ruskin University, Cambridge CB1 1PT, UK; (H.C.); (L.G.)
| | - Lata Gautam
- School of Life Sciences, Anglia Ruskin University, Cambridge CB1 1PT, UK; (H.C.); (L.G.)
| | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, 28943, Fuenlabrada, Spain;
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Pinto JM, Merzbach V, Willmott AGB, Antonio J, Roberts J. Assessing the impact of a mushroom-derived food ingredient on vitamin D levels in healthy volunteers. J Int Soc Sports Nutr 2020; 17:54. [PMID: 33176826 PMCID: PMC7659128 DOI: 10.1186/s12970-020-00387-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/04/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Prevalence of vitamin D insufficiency/deficiency has been noted in athletic populations, although less is known about recreationally active individuals. Biofortification of natural food sources (e.g. UV radiated mushrooms) may support vitamin D status and is therefore of current scientific and commercial interest. The aim of this study was to assess the impact of a mushroom-derived food ingredient on vitamin D status in recreationally active, healthy volunteers. METHODS Twenty-eight participants were randomly assigned to either: 25 μg (1000 IU) encapsulated natural mushroom-derived vitamin D2; matched-dose encapsulated vitamin D3 or placebo (PL) for 12 weeks. Venous blood samples were collected at baseline, week 6 and 12 for analysis of serum 25(OH)D2 and 25(OH)D3 using liquid chromatography mass spectrometry. Habitual dietary intake and activity were monitored across the intervention. RESULTS Vitamin D status (25(OH)DTOTAL) was significantly increased with vitamin D3 supplementation from 46.1 ± 5.3 nmol·L- 1 to 88.0 ± 8.6 nmol·L- 1 (p < 0.0001) across the intervention, coupled with an expected rise in 25(OH)D3 concentrations from 38.8 ± 5.2 nmol·L- 1 to 82.0 ± 7.9 nmol·L- 1 (p < 0.0001). In contrast, D2 supplementation increased 25(OH)D2 by + 347% (7.0 ± 1.1 nmol·L- 1 to 31.4 ± 2.1 nmol·L- 1, p < 0.0001), but resulted in a - 42% reduction in 25(OH)D3 by week 6 (p = 0.001). A net + 14% increase in 25(OH)DTOTAL was established with D2 supplementation by week 12 (p > 0.05), which was not statistically different to D3. Vitamin D status was maintained with PL, following an initial - 15% reduction by week 6 (p ≤ 0.046 compared to both supplement groups). CONCLUSIONS The use of a UV radiated mushroom food ingredient was effective in maintaining 25(OH)DTOTAL in healthy, recreationally active volunteers. This may offer an adjunct strategy in supporting vitamin D intake. However, consistent with the literature, the use of vitamin D3 supplementation likely offers benefits when acute elevation in vitamin D status is warranted.
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Affiliation(s)
- Jorge Marques Pinto
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Compass House, East Road, Cambridge, CB1 1PT, UK.
| | - Viviane Merzbach
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Compass House, East Road, Cambridge, CB1 1PT, UK
| | - Ashley G B Willmott
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Compass House, East Road, Cambridge, CB1 1PT, UK
| | - Jose Antonio
- Exercise and Sport Science, Nova Southeastern-Florida University, Davie, FL, USA
| | - Justin Roberts
- Cambridge Centre for Sport and Exercise Sciences, School of Psychology and Sport Science, Anglia Ruskin University, Compass House, East Road, Cambridge, CB1 1PT, UK.
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Willmott AGB, Sayers B, Brickley G. The physiological and perceptual responses of stand-up paddle board exercise in a laboratory- and field-setting. Eur J Sport Sci 2019; 20:1023-1033. [PMID: 31774366 DOI: 10.1080/17461391.2019.1695955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This study quantified the physiological and perceptual responses of stand-up paddle boarding (SUP) during a range of stroke rates in a laboratory- and field-setting. Ten participants (eight male, two female; mean ± standard deviation [SD] age: 23 ± 3 years; body mass: 70.5 ± 9.1 kg; height: 170 ± 9 cm; body mass index [BMI]: 24.3 ± 1.5 kg m2) completed a SUP ⩒O2peak trial, and two SUP trials in both a laboratory- and field-setting (5-min at 10, 20 and 30 strokes min-1 per stage). Energy expenditure (EE), metabolic equivalents (METs), heart rate (HR) and rating of perceived exertion (RPE) were recorded throughout. In the laboratory-setting, mean ± SD EE and METs increased (P < .001) linearly when SUP at 10 (3.3 ± 1.0 kcal min-1, 2.7 ± 0.5), 20 (5.5 ± 0.9 kcal min-1, 4.4 ± 0.7) and 30 strokes min-1 (7.6 ± 1.6 kcal min-1, 6.1 ± 1.2), respectively. During these efforts, mean ± SD percentage of maximal HR were 56 ± 5%, 69 ± 6% and 84 ± 8%, respectively. In the field-setting, mean ± SD EE and METs also increased (P < .001) linearly when SUP at 10 (3.6 ± 0.9 kcal min-1, 2.7 ± 0.9), 20 (4.3 ± 1.8 kcal min-1, 3.5 ± 1.0) and 30 strokes min-1 (6.3 ± 2.1 kcal min-1, 4.6 ± 1.4). During the three conditions, mean ± SD percentage of maximal HR were 58 ± 8%, 65 ± 7% and 73 ± 9%. SUP at ≥20 strokes min-1 in the laboratory- and field-setting meet the criteria for moderate-intensity exercise (3.0-5.9 METs). These findings may now be included in the latest Compendium of Physical Activities guidelines and offer the potential to improve cardiorespiratory fitness if SUP is undertaken regularly by young, healthy adults.
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Affiliation(s)
- Ashley G B Willmott
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - Benjamin Sayers
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Gary Brickley
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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Willmott AGB, Hayes M, James CA, Gibson OR, Maxwell NS. Heat acclimation attenuates the increased sensations of fatigue reported during acute exercise-heat stress. Temperature (Austin) 2019; 7:178-190. [PMID: 33015245 PMCID: PMC7518764 DOI: 10.1080/23328940.2019.1664370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/19/2022] Open
Abstract
Athletes exercising in heat stress experience increased perceived fatigue acutely, however it is unknown whether heat acclimation (HA) reduces the magnitude of this perceptual response and whether different HA protocols influence the response. This study investigated sensations of fatigue following; acute exercise-heat stress; short- (5-sessions) and medium-term (10-sessions) HA; and between once- (ODHA) and twice-daily HA (TDHA) protocols. Twenty male participants (peak oxygen uptake: 3.75 ± 0.47 L·min-1) completed 10 sessions (60-min cycling at ~2 W·kg-1, 45°C/20% relative humidity) of ODHA (n = 10) or non-consecutive TDHA (n = 10). Sensations of fatigue (General, Physical, Emotional, Mental, Vigor and Total Fatigue) were assessed using the multi-dimensional fatigue scale inventory-short form pre and post session 1, 5 and 10. Heat adaptation was induced following ODHA and TDHA, with reductions in resting rectal temperature and heart rate, and increased plasma volume and sweat rate (P < 0.05). General, Physical and Total Fatigue increased from pre-to-post for session 1 within both groups (P < 0.05). Increases in General, Physical and Total Fatigue were attenuated in session 5 and 10 vs. session 1 of ODHA (P < 0.05). This change only occurred at session 10 of TDHA (P < 0.05). Whilst comparative heat adaptations followed ODHA and TDHA, perceived fatigue is prolonged within TDHA. ABBREVIATIONS ∆: Change; ANOVA: Analysis of variance; HA: Heat acclimation; HR: Heart rate; IL-6: Interleukin-6; MFS-SF: Multi-dimensional fatigue symptom inventory-short form (MFSI-SF); MTHA: Medium-term heat acclimation; Na+: Sodium; ODHA: Once daily heat acclimation; PV: Plasma volume; RH: Relative humidity; RPE: Rating of perceived exertion; SD: Standard deviation; SE: Standard error of the slope coefficient or intercept; SEE : Standard error of the estimate for the regression equation; STHA: Short-term heat acclimation; TDHA: Twice daily heat acclimation; TC: Thermal Comfort; Tre: Rectal temperature; TSS: Thermal sensation; V̇O2peak: Peak oxygen uptake; WBSL: whole-body sweat loss.
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Affiliation(s)
- Ashley G B Willmott
- Centre for Sport and Exercise Science, Anglia Ruskin University, Cambridge, UK
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Mark Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Carl A. James
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
- Physiology Department, Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, UK
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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Willmott AGB, Hayes M, James CA, Dekerle J, Gibson OR, Maxwell NS. Once- and twice-daily heat acclimation confer similar heat adaptations, inflammatory responses and exercise tolerance improvements. Physiol Rep 2018; 6:e13936. [PMID: 30575321 PMCID: PMC6302546 DOI: 10.14814/phy2.13936] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/08/2018] [Indexed: 11/29/2022] Open
Abstract
This experiment aimed to investigate the efficacy of twice-daily, nonconsecutive heat acclimation (TDHA) in comparison to once-daily heat acclimation (ODHA) and work matched once- or twice-daily temperate exercise (ODTEMP, TDTEMP) for inducing heat adaptations, improved exercise tolerance, and cytokine (immune) responses. Forty males, matched biophysically and for aerobic capacity, were assigned to ODHA, TDHA, ODTEMP, or TDTEMP. Participants completed a cycling-graded exercise test, heat acclimation state test, and a time to task failure (TTTF) at 80% peak power output in temperate (TTTFTEMP : 22°C/40% RH) and hot conditions (TTTFHOT : 38°C/20% RH), before and after 10-sessions (60 min of cycling at ~2 W·kg-1 ) in 45°C/20% RH (ODHA and TDHA) or 22°C/40% RH (ODTEMP or TDTEMP). Plasma IL-6, TNF-α, and cortisol were measured pre- and postsessions 1, 5, and 10. ODHA and TDHA induced equivalent heat adaptations (P < 0.05) (resting rectal temperature [-0.28 ± 0.22, -0.28 ± 0.19°C], heart rate [-10 ± 3, -10 ± 4 b·min-1 ], and plasma volume expansion [+10.1 ± 5.6, +8.5 ± 3.1%]) and improved heat acclimation state (sweat set point [-0.22 ± 0.18, -0.22 ± 0.14°C] and gain [+0.14 ± 0.10, +0.15 ± 0.07 g·sec-1 ·°C-1 ]). TTTFHOT increased (P < 0.001) following ODHA (+25 ± 4%) and TDHA (+24 ± 10%), but not ODTEMP (+5 ± 14%) or TDTEMP (+5 ± 17%). TTTFTEMP did not improve (P > 0.05) following ODHA (+14 ± 4%), TDHA (14 ± 8%), ODTEMP (9 ± 10%) or TDTEMP (8 ± 13%). Acute (P < 0.05) but no chronic (P > 0.05) increases were observed in IL-6, TNF-α, or cortisol during ODHA and TDHA, or ODTEMP and TDTEMP. Once- and twice-daily heat acclimation conferred similar magnitudes of heat adaptation and exercise tolerance improvements, without differentially altering immune function, thus nonconsecutive TDHA provides an effective, logistically flexible method of HA, benefitting individuals preparing for exercise-heat stress.
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Affiliation(s)
- Ashley G. B. Willmott
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Mark Hayes
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Carl A. James
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
- Institut Sukan Negara (National Sports Institute)National Sports ComplexKuala LumpurMalaysia
| | - Jeanne Dekerle
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER)Brunel University LondonUxbridgeUnited Kingdom
| | - Neil S. Maxwell
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
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James CA, Richardson AJ, Watt PW, Willmott AGB, Gibson OR, Maxwell NS. Short-Term Heat Acclimation and Precooling, Independently and Combined, Improve 5-km Time Trial Performance in the Heat. J Strength Cond Res 2018; 32:1366-1375. [PMID: 28486332 DOI: 10.1519/jsc.0000000000001979] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
James, CA, Richardson, AJ, Watt, PW, Willmott, AGB, Gibson, OR, and Maxwell, NS. Short-term heat acclimation and precooling, independently and combined, improve 5-km time trial performance in the heat. J Strength Cond Res 32(5): 1366-1375, 2018-Following heat acclimation (HA), endurance running performance remains impaired in hot vs. temperate conditions. Combining HA with precooling (PC) demonstrates no additive benefit in intermittent sprint, or continuous cycling exercise protocols, during which heat strain may be less severe compared to endurance running. This study investigated the effect of short-term HA (STHA) combined with mixed methods PC, on endurance running performance and directly compared PC and HA. Nine amateur trained runners completed 5-km treadmill time trials (TTs) in the heat (32° C, 60% relative humidity) under 4 conditions; no intervention (CON), PC, short-term HA (5 days-HA) and STHA with PC (HA + PC). Mean (±SD) performance times were; CON 1,476 (173) seconds, PC 1,421 (146) seconds, HA 1,378 (116) seconds and HA + PC 1,373 (121) seconds. This equated to the following improvements versus CON; PC -3.7%, HA -6.6% and HA + PC -7.0%. Statistical differences were only observed between HA and CON (p = 0.004, d = 0.68, 95% CI [-0.27 to 1.63]) however, similar effect sizes were observed for HA + PC vs. CON (d = 0.70, 95% CI [-0.25 to 1.65]), with smaller effects between PC vs. CON (d = 0.34, 95% CI [-0.59 to 1.27]), HA vs. PC (d = 0.33, 95% CI [-0.60 to 1.26]) and HA + PC vs. PC (d = 0.36, 95% CI [-0.57 to 1.29]). Pilot testing revealed a TT typical error of 16 seconds (1.2%). Precooling offered no further benefit to performance in the acclimated individual, despite modest alleviation of physiological strain. Maintenance of running speed in HA + PC, despite reduced physiological strain, may indicate an inappropriate pacing strategy therefore, further familiarization is recommended to optimize a combined strategy. Finally, these data indicate HA, achieved through cycle training, yields a larger ergogenic effect than PC on 5-km running performance in the heat, although PC remains beneficial when HA is not possible.
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Affiliation(s)
- Carl A James
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom.,National Sports Institute, Kompleks Sukan Negara, Kuala Lumpur, Malaysia
| | - Alan J Richardson
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Peter W Watt
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Ashley G B Willmott
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Oliver R Gibson
- Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, United Kingdom
| | - Neil S Maxwell
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
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Willmott AGB, Gibson OR, James CA, Hayes M, Maxwell NS. Physiological and perceptual responses to exercising in restrictive heat loss attire with use of an upper-body sauna suit in temperate and hot conditions. Temperature (Austin) 2018; 5:162-174. [PMID: 30377634 DOI: 10.1080/23328940.2018.1426949] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/08/2018] [Indexed: 10/18/2022] Open
Abstract
The aim of this experiment was to quantify physiological and perceptual responses to exercise with and without restrictive heat loss attire in hot and temperate conditions. Ten moderately-trained individuals (mass; 69.44±7.50 kg, body fat; 19.7±7.6%) cycled for 30-mins (15-mins at 2 W.kg-1 then 15-mins at 1 W.kg-1) under four experimental conditions; temperate (TEMP, 22°C/45%), hot (HOT, 45°C/20%) and, temperate (TEMPSUIT, 22°C/45%) and hot (HOTSUIT, 45°C/20%) whilst wearing an upper-body "sauna suit". Core temperature changes were higher (P<0.05) in TEMPSUIT (+1.7±0.4°C.hr-1), HOT (+1.9±0.5°C.hr-1) and HOTSUIT (+2.3±0.5°C.hr-1) than TEMP (+1.3±0.3°C.hr-1). Skin temperature was higher (P<0.05) in HOT (36.53±0.93°C) and HOTSUIT (37.68±0.68°C) than TEMP (33.50±1.77°C) and TEMPSUIT (33.41±0.70°C). Sweat rate was greater (P<0.05) in TEMPSUIT (0.89±0.24 L.hr-1), HOT (1.14±0.48 L.hr-1) and HOTSUIT (1.51±0.52 L.hr-1) than TEMP (0.56±0.27 L.hr-1). Peak heart rate was higher (P<0.05) in TEMPSUIT (155±23 b.min-1), HOT (163±18 b.min-1) and HOTSUIT (171±18 b.min-1) than TEMP (151±20 b.min-1). Thermal sensation and perceived exertion were greater (P<0.05) in TEMPSUIT (5.8±0.5 and 14±1), HOT (6.4±0.5 and 15±1) and HOTSUIT (7.1±0.5 and 16±1) than TEMP (5.3±0.5 and 14±1). Exercising in an upper-body sauna suit within temperate conditions induces a greater physiological strain and evokes larger sweat losses compared to exercising in the same conditions, without restricting heat loss. In hot conditions, wearing a sauna suit increases physiological and perceptual strain further, which may accelerate the stimuli for heat adaptation and improve HA efficiency.
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Affiliation(s)
| | - Oliver R Gibson
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, UK
| | - Carl A James
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,National Sports Institute, Institut Sukan Negara, National Sport Complex, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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13
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James CA, Hayes M, Willmott AGB, Gibson OR, Flouris AD, Schlader ZJ, Maxwell NS. Defining the determinants of endurance running performance in the heat. Temperature (Austin) 2017; 4:314-329. [PMID: 28944273 PMCID: PMC5605161 DOI: 10.1080/23328940.2017.1333189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/16/2017] [Accepted: 05/16/2017] [Indexed: 10/25/2022] Open
Abstract
In cool conditions, physiologic markers accurately predict endurance performance, but it is unclear whether thermal strain and perceived thermal strain modify the strength of these relationships. This study examined the relationships between traditional determinants of endurance performance and time to complete a 5-km time trial in the heat. Seventeen club runners completed graded exercise tests (GXT) in hot (GXTHOT; 32°C, 60% RH, 27.2°C WBGT) and cool conditions (GXTCOOL; 13°C, 50% RH, 9.3°C WBGT) to determine maximal oxygen uptake (V̇O2max), running economy (RE), velocity at V̇O2max (vV̇O2max), and running speeds corresponding to the lactate threshold (LT, 2 mmol.l-1) and lactate turnpoint (LTP, 4 mmol.l-1). Simultaneous multiple linear regression was used to predict 5 km time, using these determinants, indicating neither GXTHOT (R2 = 0.72) nor GXTCOOL (R2 = 0.86) predicted performance in the heat as strongly has previously been reported in cool conditions. vV̇O2max was the strongest individual predictor of performance, both when assessed in GXTHOT (r = -0.83) and GXTCOOL (r = -0.90). The GXTs revealed the following correlations for individual predictors in GXTHOT; V̇O2maxr = -0.7, RE r = 0.36, LT r = -0.77, LTP r = -0.78 and in GXTCOOL; V̇O2maxr = -0.67, RE r = 0.62, LT r = -0.79, LTP r = -0.8. These data indicate (i) GXTHOT does not predict 5 km running performance in the heat as strongly as a GXTCOOL, (ii) as in cool conditions, vV̇O2max may best predict running performance in the heat.
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Affiliation(s)
- Carl A James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK.,National Sports Institute of Malaysia (Institut Sukan Negara), Bukit Jalil Stadium, Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Ashley G B Willmott
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, UK
| | - Andreas D Flouris
- FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece
| | - Zachary J Schlader
- Centre for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neil S Maxwell
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
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14
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Gibson OR, Willmott AGB, James CA, Hayes M, Maxwell NS. Power Relative to Body Mass Best Predicts Change in Core Temperature During Exercise-Heat Stress. J Strength Cond Res 2017; 31:403-414. [PMID: 27359208 DOI: 10.1519/jsc.0000000000001521] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Gibson, OR, Willmott, AGB, James, CA, Hayes, M, and Maxwell, NS. Power relative to body mass best predicts change in core temperature during exercise-heat stress. J Strength Cond Res 31(2): 403-414, 2017-Controlling internal temperature is crucial when prescribing exercise-heat stress, particularly during interventions designed to induce thermoregulatory adaptations. This study aimed to determine the relationship between the rate of rectal temperature (Trec) increase, and various methods for prescribing exercise-heat stress, to identify the most efficient method of prescribing isothermic heat acclimation (HA) training. Thirty-five men cycled in hot conditions (40° C, 39% R.H.) for 29 ± 2 minutes. Subjects exercised at 60 ± 9% V[Combining Dot Above]O2peak, with methods for prescribing exercise retrospectively observed for each participant. Pearson product moment correlations were calculated for each prescriptive variable against the rate of change in Trec (° C·h), with stepwise multiple regressions performed on statistically significant variables (p ≤ 0.05). Linear regression identified the predicted intensity required to increase Trec by 1.0-2.0° C between 20- and 45-minute periods and the duration taken to increase Trec by 1.5° C in response to incremental intensities to guide prescription. Significant (p ≤ 0.05) relationships with the rate of change in Trec were observed for prescriptions based on relative power (W·kg; r = 0.764), power (%Powermax; r = 0.679), rating of perceived exertion (RPE) (r = 0.577), V[Combining Dot Above]O2 (%V[Combining Dot Above]O2peak; r = 0.562), heart rate (HR) (%HRmax; r = 0.534), and thermal sensation (r = 0.311). Stepwise multiple regressions observed relative power and RPE as variables to improve the model (r = 0.791), with no improvement after inclusion of any anthropometric variable. Prescription of exercise under heat stress using power (W·kg or %Powermax) has the strongest relationship with the rate of change in Trec with no additional requirement to correct for body composition within a normal range. Practitioners should therefore prescribe exercise intensity using relative power during isothermic HA training to increase Trec efficiently and maximize adaptation.
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Affiliation(s)
- Oliver R Gibson
- 1Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, United Kingdom; and 2Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
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15
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Willmott AGB, Bliss A, Simpson WH, Tocker SM, Cottingham R, Maxwell NS. CAERvest® - a novel endothermic hypothermic device for core temperature cooling: safety and efficacy testing. Int J Occup Saf Ergon 2016; 24:118-128. [PMID: 27997307 DOI: 10.1080/10803548.2016.1273640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
INTRODUCTION Cooling of the body is used to treat hyperthermic individuals with heatstroke or to depress core temperature below normal for neuroprotection. A novel, chemically activated, unpowered cooling device, CAERvest®, was investigated for safety and efficacy. METHODS Eight healthy male participants (body mass 79.9 ± 1.9 kg and body fat percentage 16.1 ± 3.8%) visited the laboratory (20 °C, 40% relative humidity) on four occasions. Following 30-min rest, physiological and perceptual measures were recorded. Participants were then fitted with the CAERvest® proof of concept (PoC) or prototype 1 (P1), 2 (P2) or 3 (P3) for 60 min. Temperature, cardiovascular and perceptual measures were recorded every 5 min. After cooling, the CAERvest® was removed and the torso checked for cold-related injuries. RESULTS Temperature measures significantly (p < 0.05) reduced pre to post in all trials. Larger reductions in core and skin temperatures were observed for PoC (-0.36 ± 0.18 and -1.55 ± 0.97 °C) and P3 (-0.36 ± 0.22 and -2.47 ± 0.82 °C), compared with P1 and P2. No signs of cold-related injury were observed at any stage. CONCLUSION This study demonstrates that the CAERvest® is an effective device for reducing body temperature in healthy normothermic individuals without presence of cold injury. Further research in healthy and clinical populations is warranted.
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Affiliation(s)
- Ashley G B Willmott
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | - Alex Bliss
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
| | | | | | | | - Neil S Maxwell
- a Centre for Sport and Exercise Science and Medicine (SeSAME), Environmental Extremes Laboratory , University of Brighton , UK
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16
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Willmott AGB, Hayes M, Waldock KAM, Relf RL, Watkins ER, James CA, Gibson OR, Smeeton NJ, Richardson AJ, Watt PW, Maxwell NS. Short-term heat acclimation prior to a multi-day desert ultra-marathon improves physiological and psychological responses without compromising immune status. J Sports Sci 2016; 35:2249-2256. [PMID: 27935427 DOI: 10.1080/02640414.2016.1265142] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Multistage, ultra-endurance events in hot, humid conditions necessitate thermal adaptation, often achieved through short term heat acclimation (STHA), to improve performance by reducing thermoregulatory strain and perceptions of heat stress. This study investigated the physiological, perceptual and immunological responses to STHA prior to the Marathon des Sables. Eight athletes (age 42 ± 4 years and body mass 81.9 ± 15.0 kg) completed 4 days of controlled hyperthermia STHA (60 min·day‒1, 45°C and 30% relative humidity). Pre, during and post sessions, physiological and perceptual measures were recorded. Immunological measures were recorded pre-post sessions 1 and 4. STHA improved thermal comfort (P = 0.02), sensation (P = 0.03) and perceived exertion (P = 0.04). A dissociated relationship between perceptual fatigue and Tre was evident after STHA, with reductions in perceived Physical (P = 0.04) and General (P = 0.04) fatigue. Exercising Tre and HR did not change (P > 0.05) however, sweat rate increased 14% (P = 0.02). No changes were found in white blood cell counts or content (P > 0.05). Four days of STHA facilitates effective perceptual adaptations, without compromising immune status prior to an ultra-endurance race in heat stress. A greater physiological strain is required to confer optimal physiological adaptations.
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Affiliation(s)
- Ashley G B Willmott
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Mark Hayes
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Kirsty A M Waldock
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Rebecca L Relf
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Emily R Watkins
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Carl A James
- b National Sports Institute (Institut Sukan Negara) , National Sport Complex , Kuala Lumpur , Malaysia
| | - Oliver R Gibson
- c Centre for Human Performance, Exercise and Rehabilitation , Brunel University London , London , UK
| | - Nicholas J Smeeton
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Alan J Richardson
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Peter W Watt
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Neil S Maxwell
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
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James CA, Willmott AGB, Richardson AJ, Watt PW, Maxwell NS. Ischaemic preconditioning does not alter the determinants of endurance running performance in the heat. Eur J Appl Physiol 2016; 116:1735-45. [PMID: 27406142 DOI: 10.1007/s00421-016-3430-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 07/05/2016] [Indexed: 11/26/2022]
Abstract
PURPOSE Ischaemic preconditioning (IP) has been shown to be ergogenic for endurance performance in normothermic conditions and alleviate physiological strain under hypoxia, potentially through haemodynamic and/or metabolic mechanisms. Exertional hyperthermia is characterised by competition for blood flow between the muscles and skin, an enhanced metabolic strain and impaired endurance performance. This study investigated the effect of IP on the determinants of endurance performance, through an incremental exercise test in the heat. METHOD Eleven males completed two graded exercise tests in the heat (32 °C, 62 % RH) until volitional exhaustion, preceded by IP (4 × 5 min 220 mmHg bilateral upper leg occlusion) or a control (CON) condition (4 × 5-min 50 mmHg bilateral). RESULT IP did not improve running speeds at fixed blood lactate concentrations of 2 and 4 mMol L(-1) (p = 0.828), or affect blood glucose concentration throughout the trial [mean (±SD); CON 5.03 (0.94) mMol L(-1), IP 5.47 (1.38) mMol L(-1), p = 0.260). There was no difference in [Formula: see text]O2max [CON 55.5 (3.7) mL kg(-1) min(-1), IP 56.0 (2.6) mL kg(-1) min(-1), p = 0.436], average running economy [CON 222.3 (18.0) mL kg(-1) km(-1), IP 218.9 (16.5) mL kg(-1) km(-1), p = 0.125], or total running time during graded exercise [CON 347 (42) s, IP 379 (68) s, p = 0.166]. The IP procedure did not change muscle temperature [CON ∆ = 0.55 (0.57) °C, IP ∆ = 0.78 (0.85) °C, p = 0.568], but did reduce T CORE during exercise (~-0.1 °C, p = 0.001). CONCLUSION The novel application of IP prior to exercise in the heat does not enhance the determinants of endurance performance. For events where IP appears ergogenic, muscle warming strategies are unnecessary as IP does not influence deep muscle temperature.
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Affiliation(s)
- Carl A James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, BN20 7SN, UK.
| | - Ashley G B Willmott
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, BN20 7SN, UK
| | - Alan J Richardson
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, BN20 7SN, UK
| | - Peter W Watt
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, BN20 7SN, UK
| | - Neil S Maxwell
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, BN20 7SN, UK
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18
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Willmott AGB, Gibson OR, Hayes M, Maxwell NS. The effects of single versus twice daily short term heat acclimation on heat strain and 3000m running performance in hot, humid conditions. J Therm Biol 2016; 56:59-67. [PMID: 26857978 DOI: 10.1016/j.jtherbio.2016.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/04/2016] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
Abstract
Endurance performances are impaired under conditions of elevated heat stress. Short term heat acclimation (STHA) over 4-6 days can evoke rapid adaptation, which mitigate decrements in performance and alleviate heat strain. This study investigated the efficacy of twice daily heat acclimation (TDHA) compared to single session per day heat acclimation (SDHA) and normothermic training, at inducing heat acclimation phenotype and its impact upon running performance in hot, humid conditions. Twenty one, moderately trained males were matched and assigned to three groups; SDHA (mean±SD) (peak oxygen consumption [V̇O2peak] 45.8±6.1mLkg(-1)min(-1), body mass 81.3±16.0kg, stature 182±3cm), TDHA (46.1±7.0mLkg(-1)min(-1), 80.1±11.9kg, 178±4cm) or control (CON) (47.1±3.5mLkg(-1)min(-1), 78.6±16.7kg, 178±4cm). Interventions consisted of 45min cycling at 50% V̇O2peak, once daily for 4d (SDHA) and twice daily for 2d (TDHA), in 35°C, 60% relative humidity (RH), and once daily for 4 days (CON) in 21°C, 40% RH. Participants completed a pre- and post-intervention 5km treadmill run trial in 30°C, 60% RH, where the first 2km were fixed at 40% V̇O2peak and the final 3km was self-paced. No statistically significant interaction effects occurred within- or between-groups over the 2-4 days intervention. While within-group differences were found in physiological and perceptual measures during the fixed intensity trial post-intervention, they did not statistically differ between-groups. Similarly, TDHA (-36±34s [+3.5%]) and SDHA (-26±28s [+2.8%]) groups improved 3km performances (p=0.35), but did not differ from CON (-6±44s [+0.6%]). This is the first study to investigate the effects of HA twice daily and compare it with traditional single session per day STHA. These STHA protocols may have the ability to induce partial adaptive responses to heat stress and possibly enhance performance in environmentally challenging conditions, however, future development is warranted to optimise the administration to provide a potent stimuli for heat adaptation in athletic and military personnel within a rapid regime.
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Affiliation(s)
- A G B Willmott
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK.
| | - O R Gibson
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK; Centre for Sports Medicine and Human Performance (CSMHP), Brunel University, London, UK
| | - M Hayes
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| | - N S Maxwell
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
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Willmott AGB, Hayes M, Dekerle J, Maxwell NS. The reliability of a heat acclimation state test prescribed from metabolic heat production intensities. J Therm Biol 2015; 53:38-45. [PMID: 26590454 DOI: 10.1016/j.jtherbio.2015.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 08/14/2015] [Accepted: 08/14/2015] [Indexed: 11/27/2022]
Abstract
Acclimation state indicates an individual's phenotypic response to a thermally stressful environment, where changes in heat dissipation capacity are determined during a heat acclimation state test (HAST). Variations in thermoregulatory and sudomotor function are reported while exercising at intensities relative to maximal oxygen uptake. This inter-individual variation is not true when intensity is prescribed to elicit a fixed rate of metabolic heat production (Ḣprod). This study investigated the reliability of peak Tre and two composite measures (sweat gain and sweat setpoint) derived from indices of thermosensitivity during a HAST prescribed from Ḣprod intensities. Fourteen participants (mean±SD; age 23±3 years, stature 174±7cm, body mass 75.0±9.4kg, body surface area 1.9±0.1m(2), peak oxygen consumption [V̇O2peak] 3.49±0.53Lmin(-1)) completed a lactate threshold-V̇O2peak test and two duplicate Ḣprod HASTs on a cycle ergometer. The HAST consisted of three, 30-min periods of exercise at fixed Ḣprod intensities relative to body mass (3, 4.5 and 6Wkg(-1)), within hot dry conditions (44.7±1.8°C and 18.1±4.7% relative humidity). Peak Tre (38.20±0.36 vs. 38.16±0.42°C, p=0.54), sweat setpoint (36.76±0.34 and 36.79±0.38°C, p=0.68) and sweat gain (0.37±0.14 and 0.40±0.18gs(-1)°C(-1), p=0.40) did not differ between HASTs. Typical error of measurement (TEM), coefficient variation (CV) and intra-class coefficient of correlation (ICC) were 0.19°C, 0.5% and 0.80 for peak Tre, 0.21°C, 0.6% and 0.65 for sweat setpoint and 0.09gs(-1)°C(-1), 28% and 0.68 for sweat gain, respectively. The use of fixed Ḣprod intensities relative to body mass is a reliable method for measuring Tre and ascertaining sweat setpoint during a HAST, whereas, sweat gain displays greater variability. A Ḣprod HAST appears sufficiently reliable for quantifying heat acclimation state, where TEM in peak Tre and sweat setpoint are small enough to identify physiologically meaningful improvements post-intervention.
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Affiliation(s)
- A G B Willmott
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK; School of Sport and Service Management, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK.
| | - M Hayes
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK; School of Sport and Service Management, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK
| | - J Dekerle
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK; School of Sport and Service Management, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK
| | - N S Maxwell
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK; School of Sport and Service Management, University of Brighton, Welkin House, Denton Road, Eastbourne BN20 7SN, UK
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