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Vine CAJ, Spurr TJ, Blacker SD. Food for thought: dietary nootropics for the optimisation of military operators' cognitive performance. BMJ Mil Health 2024:e002706. [PMID: 38851246 DOI: 10.1136/military-2024-002706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 04/27/2024] [Indexed: 06/10/2024]
Abstract
Nootropics are compounds that enhance cognitive performance and have been highlighted as a medium-term human augmentation technology that could support soldier performance. Given the differing ethical, safety and legal considerations associated with the pharmaceutical subset of nootropics, this analysis focuses on dietary supplementation which may enhance cognition during training and operations. Numerous supplements have been investigated as possible nootropics; however, research is often not context specific or of high quality, leading to questions regarding efficacy. There are many other complex cofactors that may affect the efficacy of any dietary nootropic supplement which is designed to improve cognition, such as external stressors (eg, sleep deprivation, high physical workloads), task specifics (eg, cognitive processes required) and other psychological constructs (eg, placebo/nocebo effect). Moreover, military population considerations, such as prior nutritional knowledge and current supplement consumption (eg, caffeine), along with other issues such as supplement contamination, should be evaluated when considering dietary nootropic use within military populations. However, given the increasing requirement for cognitive capabilities by military personnel to complete role-related tasks, dietary nootropics could be highly beneficial in specific contexts. While current evidence is broadly weak, nutritional nootropic supplements may be of most use to the military end user during periods of high military specific stress. Currently, caffeine and L-tyrosine are the leading nootropic supplement candidates within the military context. Future military-specific research on nootropics should be of high quality and use externally valid methodologies to maximise the translation of research to practice.
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Affiliation(s)
| | - T J Spurr
- Institute of Applied Sciences, University of Chichester, Chichester, UK
| | - Sam D Blacker
- Institute of Applied Sciences, University of Chichester, Chichester, UK
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2
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Gavel EH, Hawke KV, Logan-Sprenger HM. The Effect of Menthol Mouth Rinsing and Fluid Temperature on Male Cycling Performance in Thermoneutral Conditions. Nutrients 2024; 16:1016. [PMID: 38613049 PMCID: PMC11013829 DOI: 10.3390/nu16071016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
PURPOSE The purpose of this study was to determine the effect of a menthol (MEN) mouth rinse (MR) on cycling time trial (TT) performance in thermoneutral conditions and to explore the impact of fluid temperature (cold water [CW] or thermoneutral water [TNW]) on MEN's effect on performance. METHODS Twelve trained male cyclists (VO2 peak, 61.4 ± 12.1 mL/kg/min) completed a cycling TT in thermoneutral conditions (21 ± 0.2 °C, 40 ± 0.6% relative humidity) with four different mouth rinses: (1) MEN + CW; (2) MEN + TNW; (3) CW; and (4) TNW. The time to complete the TT and the power output (W) were recorded. The ratings of perceived exertion (RPE, Borg 6-20), thermal sensation (TS), and thermal comfort (TC) were recorded prior to and throughout the TT. The core body temperature (Tc) and heart rate (HR) were recorded throughout. RESULTS The TT duration was not significantly different between trials (MEN + TNW: 38:11 ± 12:48, MEN + CW: 37:21 ± 13:00, CW: 38:12 ± 13:54, TNW: 36:06 ± 14:12 mins:secs, p < 0.05). The mean trial power output did not significantly differ between conditions (>0.05). The Tc, HR, RPE, TS, and TC were not significantly different between trials (p > 0.05). CONCLUSION The results suggest that a MEN MR with either CW or TNW does not significantly improve cycling TT performance in trained male cyclists compared to a CW or TNW MR in thermoneutral conditions.
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Affiliation(s)
- Erica H. Gavel
- Faculty of Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada;
- Departments of Family Medicine and Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48109, USA
- Tanenbaum Institute for Science in Sport, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Kierstyn V. Hawke
- Faculty of Health Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
| | - Heather M. Logan-Sprenger
- Faculty of Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada;
- Faculty of Health Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
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Gavel EH, Barreto G, Hawke KV, Stellingwerff T, James LJ, Saunders B, Logan-Sprenger HM. How Cool is That? The Effects of Menthol Mouth Rinsing on Exercise Capacity and Performance: A Systematic Review and Meta-analysis. SPORTS MEDICINE - OPEN 2024; 10:18. [PMID: 38381237 PMCID: PMC10881929 DOI: 10.1186/s40798-024-00679-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/10/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND Menthol (MEN) mouth rinsing (MR) has gained considerable interest in the athletic population for exercise performance; however, the overall magnitude of effect is unknown. OBJECTIVE The aim of this systematic review and meta-analysis was to determine the efficacy of menthol MEN MR and the impact it has on exercise capacity and performance. METHODS Three databases were searched with articles screened according to the inclusion/exclusion criteria. Three-level meta-analyses were used to investigate the overall efficacy of MEN MR and the impact it has on exercise capacity and performance. Meta-regressions were then performed with 1) mean VO2peak, 2) MEN swilling duration; 3) the MEN concentration of MR solution, 4) the number of executed swills throughout a single experiment, 5) the use of flavoured sweetened, non-caloric, or non-flavoured neutral solutions as controls, 6) mean environmental temperature at the time of exercise tests, and 7) exercise type as fixed factors to evaluate their influence on the effects of MEN MR. RESULTS Ten MEN MR studies included sufficient information pertaining to MEN MR and exercise performance and capacity. MR with MEN resulted in no significant change in capacity and performance (SMD = 0.12; 95% CI - 0.08, 0.31; p = 0.23, n = 1, tau21 < 0.0001, tau22 = < 0.0001, I2 = 0%). No significant influence was detected in meta-regressions for VO2peak, (estimate: 0.03; df = 8; 95% CI - 0.03, 0.09; p = 0.27), swilling duration (5 vs. 10 s: 0.00; df = 16; 95% CI - 0.41, 0.41; p = 1.0), MEN concentration (low [0.01%] vs. high [0.1%]: - 0.08; df = 15; 95% CI - 0.49, 0.32; p = 0.67), number of swills (estimate: 0.02; df = 13; 95% CI - 0.05, 0.09; p = 0.56), the use of flavoured sweetener or non-caloric as control (non-flavoured vs. flavoured: 0.12; df = 16; 95% CI - 0.30, 0.55; p = 0.55) or mean room temperature during exercise tests (estimate: 0.01; df = 16; 95% CI - 0.02, 0.04; p = 0.62). CONCLUSION MEN MR did not significantly improve overall exercise capacity and performance, though those involved in endurance exercise may see benefits.
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Affiliation(s)
- Erica H Gavel
- Faculty of Science, Ontario Tech University, Oshawa, ON, Canada.
| | - Gabriel Barreto
- Applied Physiology and Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Kierstyn V Hawke
- Faculty of Health Science, Ontario Tech University, Oshawa, ON, Canada
| | - Trent Stellingwerff
- Canadian Sport Institute - Pacific, Victoria, BC, Canada
- Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
| | - Lewis J James
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Bryan Saunders
- Applied Physiology and Nutrition Research Group, Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil
- Institute of Orthopaedics and Traumatology, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil
| | - Heather M Logan-Sprenger
- Faculty of Science, Ontario Tech University, Oshawa, ON, Canada
- Faculty of Health Science, Ontario Tech University, Oshawa, ON, Canada
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van de Kerkhof TM, Bongers CCWG, Périard JD, Eijsvogels TMH. Performance Benefits of Pre- and Per-cooling on Self-paced Versus Constant Workload Exercise: A Systematic Review and Meta-analysis. Sports Med 2024; 54:447-471. [PMID: 37803106 PMCID: PMC10933154 DOI: 10.1007/s40279-023-01940-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2023] [Indexed: 10/08/2023]
Abstract
BACKGROUND AND OBJECTIVE Exercise in hot environments impairs endurance performance. Cooling interventions can attenuate the impact of heat stress on performance, but the influence of an exercise protocol on the magnitude of performance benefit remains unknown. This meta-analytical review compared the effects of pre- and per-cooling interventions on performance during self-paced and constant workload exercise in the heat. METHODS The study protocol was preregistered at the Open Science Framework ( https://osf.io/wqjb3 ). A systematic literature search was performed in PubMed, Web of Science, and MEDLINE from inception to 9 June, 2023. We included studies that examined the effects of pre- or per-cooling on exercise performance in male individuals under heat stress (> 30 °C) during self-paced or constant workload exercise in cross-over design studies. Risk of bias was assessed using the Cochrane Risk of Bias Tool for randomized trials. RESULTS Fifty-nine studies (n = 563 athletes) were identified from 3300 records, of which 40 (n = 370 athletes) used a self-paced protocol and 19 (n = 193 athletes) used a constant workload protocol. Eighteen studies compared multiple cooling interventions and were included more than once (total n = 86 experiments and n = 832 paired measurements). Sixty-seven experiments used a pre-cooling intervention and 19 used a per-cooling intervention. Average ambient conditions were 34.0 °C [32.3-35.0 °C] and 50.0% [40.0-55.3%] relative humidity. Cooling interventions attenuated the performance decline in hot conditions and were more effective during a constant workload (effect size [ES] = 0.62, 95% confidence interval [CI] 0.44-0.81) compared with self-paced exercise (ES = 0.30, 95% CI 0.18-0.42, p = 0.004). A difference in performance outcomes between protocols was only observed with pre-cooling (ES = 0.74, 95% CI 0.50-0.98 vs ES = 0.29, 95% CI 0.17-0.42, p = 0.001), but not per-cooling (ES = 0.45, 95% CI 0.16-0.74 vs ES = 0.35, 95% CI 0.01-0.70, p = 0.68). CONCLUSIONS Cooling interventions attenuated the decline in performance during exercise in the heat, but the magnitude of the effect is dependent on exercise protocol (self-paced vs constant workload) and cooling type (pre- vs per-cooling). Pre-cooling appears to be more effective in attenuating the decline in exercise performance during a constant workload compared with self-paced exercise protocols, whereas no differences were found in the effectiveness of per-cooling.
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Affiliation(s)
- Tessa M van de Kerkhof
- Department of Physiology (392), Radboud University Medical Center, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Coen C W G Bongers
- Department of Physiology (392), Radboud University Medical Center, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- School of Sports and Exercise, HAN University of Applied Sciences, Nijmegen, The Netherlands
| | - Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Canberra, ACT, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology (392), Radboud University Medical Center, Radboud Institute for Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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Roriz M, Brito J, Teixeira FJ, Spyrou K, Teixeira VH. The effect of menthol rinsing before intermittent exercise on physiological, physical, and thermo-behavioral responses of male football referees in hot and humid environment. Front Sports Act Living 2024; 6:1334739. [PMID: 38318484 PMCID: PMC10839052 DOI: 10.3389/fspor.2024.1334739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/04/2024] [Indexed: 02/07/2024] Open
Abstract
Introduction In the current experiment, we aimed to evaluate whether eliciting pre-exercise non-thermal cooling sensations would alter perceptual measures, and physical and physiological responses in football referees. Methods Nine highly trained male football referees undertook two 45-minute intermittent exercise protocols in hot and humid conditions (34.2 ± 0.6°C, 62.5 ± 1.0% relative humidity). In a randomized counterbalanced crossover design, 1 of 2 beverages were given before the warm-up: a 0.01% menthol solution or a placebo noncaloric solution. Physical performance was quantified as total distance covered in each of the three 15-minute exercise blocks. Core temperature, heart rate, thermal sensation and thermal comfort were measured at rest and after each exercise block. Results No changes were observed between trials and over time for distance covered. No main effect of mouth rinse was observed for core temperature and heart rate, but both increased over time in all conditions (P < 0.001). Thermal sensation and thermal comfort were significantly improved with menthol after mouth-rinsing (P < 0.05), but with no differences at any other time-point. Discussion These results indicate that non-thermal cooling oral stimuli provide immediate behavioral changes but may not influence physiological or physical responses in football referees, during intermittent exercise in hot and humid environments. Clinical Trial Registration www.clinicaltrials.gov, identifier NCT05632692.
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Affiliation(s)
- Maria Roriz
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation, Oeiras, Portugal
| | - Filipe J. Teixeira
- Interdisciplinary Center for the Study of Human Performance (CIPER), Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz-Quebrada, Portugal
- Atlântica, Instituto Universitário, Fábrica da Pólvora de Barcarena, Barcarena, Portugal
| | - Konstantinos Spyrou
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
- Facultad de Deporte, UCAM Universidad Católica de Murcia, Murcia, Spain
| | - Vitor Hugo Teixeira
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
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Villegas-Serna T, Wilson LJ, Curtis C. Topical application of L-Menthol - Physiological and genetic considerations to assist in developing female athlete research: A narrative review. J Therm Biol 2024; 119:103758. [PMID: 38070272 DOI: 10.1016/j.jtherbio.2023.103758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 02/25/2024]
Abstract
L-menthol is a cyclic monoterpene derived from aromatic plants, which gives a cooling sensation upon application. With this in mind, L-menthol is beginning to be considered as a potential ergogenic aid for exercise and sporting competitions, particularly in hot environments, however female-specific research is lacking. The aim of this narrative review is to summarize available literature relating to topical application of L-menthol and provide commentary on avenues of consideration relating to future research developments of topical L-menthol in female athletes. From available studies in male participants, L-menthol topical application results in no endurance exercise performance improvements, however decreases in thermal sensation are observed. Mixed results are observed within strength performance parameters. Several genetic variations and single nucleotide polymorphisms have been identified in relation to sweat production, fluid loss and body mass changes - factors which may influence topical application of L-menthol. More specifically to female athletes, genetic variations relating to sweat responses and skin thickness, phases of the menstrual cycle, and body composition indices may affect the ergogenic effects of L-menthol topical application, via alterations in thermogenic responses, along with differing tissue distribution compared to their male counterparts. This narrative review concludes that further development of female athlete research and protocols for topical application of L-menthol is warranted due to physiological and genetic variations. Such developments would benefit research and practitioners alike with further personalized sport science strategies around phases of the menstrual cycle and body composition indices, with a view to optimize ergogenic effects of L-menthol.
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Affiliation(s)
- Tatiana Villegas-Serna
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Pamplona, Spain; University of Navarra, Pamplona, Spain
| | - Laura J Wilson
- London Sport Institute, Middlesex University, London, NW4 4BT, United Kingdom
| | - Christopher Curtis
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Pamplona, Spain; University of Navarra, Pamplona, Spain.
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Miranda Neto M, Meireles ACF, Alcântara MA, de Magalhães Cordeiro AMT, Silva AS. Peppermint essential oil (Mentha piperita L.) increases time to exhaustion in runners. Eur J Nutr 2023; 62:3411-3422. [PMID: 37665425 DOI: 10.1007/s00394-023-03235-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 08/08/2023] [Indexed: 09/05/2023]
Abstract
PURPOSE This study aimed to evaluate the capacity of peppermint essential oil to improve the physical performance of runners in running protocol until exhaustion. METHODS In a clinical, randomized, double-blind, cross-over and controlled study, fourteen male recreational runners (37.1 ± 2.0 years; 24 ± 1.1 kg/m2; 53.1 ± 1.7 mL kg min) performed two runs to exhaustion at 70% of VO2max, after intake of 500 mL of water added with 0.05 mL of peppermint essential oil (PEO) or placebo (PLA), plus 400 mL of the drink during the initial part of the exercise. Records were made of body temperature (BT), thermal sensation (TS), thermal comfort (TC), subjective perception of effort (SPE), sweat rate (SR), and urine volume and density. RESULTS Time to exhaustion was 109.9 ± 6.9 min in PEO and 98.5 ± 6.2 min in PLA (p = 0.009; effect size: 0.826). No significant changes were observed in the values of BT, TS, TC, SPE, SR, lost body mass, and urine volume and density (p > 0.05). CONCLUSION Peppermint essential oil added to water before and during a race significantly increases the time to exhaustion of recreational runners but without altering BT, TS, TC, or hydration status, so the mechanisms involved were not clarified in this study. BRAZILIAN REGISTRY OF CLINICAL TRIALS (REBEC) RBR-75zt25z.
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Affiliation(s)
- Manoel Miranda Neto
- Postgraduate Program in Nutrition Sciences, Health Sciences Center, Federal University of Paraíba, Campus I, University City, João Pessoa, Paraíba, 58059-900, Brazil
| | - Ana Carolina Freitas Meireles
- Laboratory of Physical Training Studies Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Maristela Alves Alcântara
- Food Technology Department, Center for Technology and Regional Development, Federal University of Paraíba, Campus I, João Pessoa, Paraíba, Brazil
| | | | - Alexandre Sérgio Silva
- Postgraduate Program in Nutrition Sciences, Health Sciences Center, Federal University of Paraíba, Campus I, University City, João Pessoa, Paraíba, 58059-900, Brazil.
- Associate Postgraduate Program in Physical Education, University of Pernambuco/Federal University of Paraíba, João Pessoa, Paraíba, Brazil.
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Best R, Williams JM, Pearce J. The Physiological Requirements of and Nutritional Recommendations for Equestrian Riders. Nutrients 2023; 15:4977. [PMID: 38068833 PMCID: PMC10708571 DOI: 10.3390/nu15234977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Equestrian sport is under-researched within the sport science literature, creating a possible knowledge vacuum for athletes and support personnel wishing to train and perform in an evidence-based manner. This review aims to synthesise available evidence from equitation, sport, and veterinary sciences to describe the pertinent rider physiology of equestrian disciplines. Estimates of energy expenditure and the contribution of underpinning energy systems to equestrian performance are used to provide nutrition and hydration recommendations for competition and training in equestrian disciplines. Relative energy deficiency and disordered eating are also considered. The practical challenges of the equestrian environment, including competitive, personal, and professional factors, injury and concussion, and female participation, are discussed to better highlight novelty within equestrian disciplines compared to more commonly studied sports. The evidence and recommendations are supported by example scenarios, and future research directions are outlined.
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Affiliation(s)
- Russ Best
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Te Pūkenga, Hamilton 3200, New Zealand
| | - Jane M. Williams
- Department of Animal Science, Hartpury University, Hartpury Gl19 3BE, UK;
| | - Jeni Pearce
- High Performance Sport New Zealand, Auckland 0632, New Zealand;
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Peel J, John K, Page J, Jeffries O, Heffernan SM, Tallent J, Waldron M. Topical application of isolated menthol and combined menthol-capsaicin creams: Exercise tolerance, thermal perception, pain, attentional focus and thermoregulation in the heat. Eur J Sport Sci 2023; 23:2038-2048. [PMID: 37161852 DOI: 10.1080/17461391.2023.2211966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We determined the effects of topically applied (i) isolated menthol cream, (ii) menthol and capsaicin co-application or (iii) placebo cream on exercise tolerance, thermal perception, pain, attentional focus and thermoregulation during exercise in the heat. Ten participants cycled at 70% maximal power output until exhaustion in 35°C and 20% relative humidity after application of (i) 5% isolated menthol, (ii) 5% menthol and 0.025% capsaicin co-application or (iii) placebo cream. Thermo-physiological responses were measured during exercise, with attentional focus and pain determined post-exercise on a 0-to-10 scale. Across the three conditions, time to exhaustion was 13.4 ± 4.8 min, mean ± SD infrared tympanic and skin temperature was 37.2 ± 0.6°C and 35.1 ± 1.2°C, respectively, and heart rate was 152 ± 47 bpm, with no changes between conditions (p > 0.05). Perceived exertion was lower in the isolated menthol vs. all other conditions (p < 0.05, ηp2 = 0.44). Thermal sensation was higher in menthol-capsaicin co-application vs. isolated menthol (p < 0.05, d = 1.1), while sweat rate was higher for capsaicin and menthol co-application compared to menthol (p < 0.05, d = 0.85). The median and interquartile range scores for pain were lower (p < 0.05) in the menthol condition (8, 7-8) compared to both menthol and capsaicin (10, 9-10) and placebo (9, 9-10), which was coupled with a greater distraction (p < 0.05) in the menthol condition (9, 7-10) compared to placebo (6, 5-7). Despite no performance effects for any topical cream application condition, these data reiterate the advantageous perceptual and analgesic role of menthol application and demonstrate no advantage of co-application with capsaicin.HighlightsTopical application of isolated menthol cream to cold-sensitive areas of the body during exhaustive exercise in the heat, elicited reduced perception of pain and enhanced sensation of cooling.While this reduction in generally unpleasant feelings (i.e. pain and heat) were coupled with lower RPE scores in the menthol condition and could be considered beneficial, there was no apparent ergogenic effect in an exercise tolerance test.Co-application of capsaicin and menthol appeared to inhibit the positive sensory effects elicited by menthol.Isolated menthol can induce changes in cognitive processes related to pain and exertion, while also reducing thermal sensation; however, the decision to use menthol creams must be balanced with the limited performance or thermoregulatory effects reported herein during exercise in hot environments.
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Affiliation(s)
- Jenny Peel
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Kevin John
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Joe Page
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Owen Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Shane M Heffernan
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
| | - Jamie Tallent
- School of Sport, Rehabilitation, and Exercise Sciences, University of Essex, Colchester, UK
- Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences, School of Primary and Allied Health Care, Monash University, Colchester, Australia
| | - Mark Waldron
- A-STEM Centre, Faculty of Science & Engineering, Swansea University, Swansea, UK
- Welsh Institute of Performance Science, Swansea University, Swansea, UK
- School of Health and Behavioural Sciences, University of the Sunshine Coast, Queensland, Australia
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10
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Roriz M, Brito J, Teixeira FJ, Spyrou K, Teixeira VH. Menthol mouth rinsing and performance in elite football referees in the heat: A study protocol for a randomized crossover trial. Contemp Clin Trials Commun 2023; 35:101202. [PMID: 37691850 PMCID: PMC10492210 DOI: 10.1016/j.conctc.2023.101202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 08/09/2023] [Accepted: 08/20/2023] [Indexed: 09/12/2023] Open
Abstract
Background Within professional European competitions, matches can be played in extreme environmental temperatures, ranging from -5 °C to +30 °C in different countries. Furthermore, the World Cups are usually played in the summer months, when temperatures can exceed 35 °C, increasing physiological stress. Practical and cost-effective cooling strategies may be implemented to help players and referees to cope with exercising in the heat. No study has evaluated the effect of non-thermal internal cooling techniques regarding performance responses on elite football referees, so far. This study aims to analyse the effects of a menthol mouth rinse regarding physical, physiological, and perceptual performance in elite male football referees, during a 90-min football protocol in the heat. Methods At least thirteen male football referees will be recruited to perform two intermittent football protocols, separated by no less than 7 days. After passing the eligibility criteria, the participants will be randomly assigned to 1 of 2 beverages: (1) intervention - menthol solution 0.01% and (2) placebo - noncaloric berry-flavored solution, both at room temperature. The beverages will be given before warm-up (pre-cooling) and at the half-time (per-cooling). The trials will follow a randomized counterbalanced crossover design, single blinded, and will take place in indoor facilities, with Wet Bulb Globe Temperature (WBGT) > 30 °C, at the same time of the day to control for circadian variations. Impact of the project The results of this study are expected to determine whether mouth rinsing a menthol solution before and during a football exercise protocol performed in the heat will alter perceptual measures and help ease physiological strain and attenuate performance decrements in elite male football referees, comparing to a non-cooling strategy. Thus, we can be closer to defining nutritional strategies of internal cooling that may be an advantage for the performance of the football referees in the heat. Trial registration www.ClinicalTrials.gov NCT05632692 registered on 20 November 2022.
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Affiliation(s)
- Maria Roriz
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), 4150-180, Porto, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation, Oeiras, Portugal
| | - Filipe J. Teixeira
- Interdisciplinary Center for the Study of Human Performance (CIPER), Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-688, Cruz-Quebrada, Portugal
- Atlântica, Instituto Universitário, Fábrica da Pólvora de Barcarena, 2730-036, Barcarena, Portugal
| | - Konstantinos Spyrou
- UCAM Research Center for High Performance Sport, UCAM Universidad Católica de Murcia, Murcia, Spain
- Facultad de Deporte, UCAM Universidad Católica de Murcia, Murcia, Spain
| | - Vitor Hugo Teixeira
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), 4150-180, Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), 4200-450, Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), 4050-600, Porto, Portugal
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11
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Heydenreich J, Koehler K, Braun H, Grosshauser M, Heseker H, Koenig D, Lampen A, Mosler S, Niess A, Schek A, Carlsohn A. Effects of internal cooling on physical performance, physiological and perceptional parameters when exercising in the heat: A systematic review with meta-analyses. Front Physiol 2023; 14:1125969. [PMID: 37113693 PMCID: PMC10126464 DOI: 10.3389/fphys.2023.1125969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/27/2023] [Indexed: 04/29/2023] Open
Abstract
Background: An elevated core temperature (Tcore) increases the risk of performance impairments and heat-related illness. Internal cooling (IC) has the potential to lower Tcore when exercising in the heat. The aim of the review was to systematically analyze the effects of IC on performance, physiological, and perceptional parameters. Methods: A systematic literature search was performed in the PubMed database on 17 December 2021. Intervention studies were included assessing the effects of IC on performance, physiological, or perceptional outcomes. Data extraction and quality assessment were conducted for the included literature. The standardized mean differences (SMD) and 95% Confidence Intervals (CI) were calculated using the inverse-variance method and a random-effects model. Results: 47 intervention studies involving 486 active subjects (13.7% female; mean age 20-42 years) were included in the meta-analysis. IC resulted in significant positive effects on time to exhaustion [SMD (95% CI) 0.40 (0.13; 0.67), p < 0.01]. IC significantly reduced Tcore [-0.19 (22120.34; -0.05), p < 0.05], sweat rate [-0.20 (-0.34; -0.06), p < 0.01], thermal sensation [-0.17 (-0.33; -0.01), p < 0.05], whereas no effects were found on skin temperature, blood lactate, and thermal comfort (p > 0.05). IC resulted in a borderline significant reduction in time trial performance [0.31 (-0.60; -0.02), p = 0.06], heart rate [-0.13 (-0.27; 0.01), p = 0.06], rate of perceived exertion [-0.16 (-0.31; -0.00), p = 0.05] and borderline increased mean power output [0.22 (0.00; 0.44), p = 0.05]. Discussion: IC has the potential to affect endurance performance and selected physiological and perceptional parameters positively. However, its effectiveness depends on the method used and the time point of administration. Future research should confirm the laboratory-based results in the field setting and involve non-endurance activities and female athletes. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022336623.
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Affiliation(s)
- Juliane Heydenreich
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Institute of Sports Sciences, Johannes Gutenberg-University of Mainz, Mainz, Germany
- *Correspondence: Juliane Heydenreich,
| | - Karsten Koehler
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Hans Braun
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Manfred Donike Institute for Doping Analysis, Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Mareike Grosshauser
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Olympic Center Rhineland-Palatinate/Saarland, Saarbrücken, Germany
| | - Helmut Heseker
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Institute of Nutrition, Consumption and Health, University of Paderborn, Paderborn, Germany
| | - Daniel Koenig
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Division of Sports Medicine, Exercise Physiology and Prevention, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria
| | - Alfonso Lampen
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Risk Assessment Strategies, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Stephanie Mosler
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Olympic Center Stuttgart, Stuttgart, Germany
| | - Andreas Niess
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Sports Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Alexandra Schek
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Editorial Team of the Journal Leistungssport, German Olympic Sports Confederation, Frankfurt, Germany
| | - Anja Carlsohn
- Working Group Sports Nutrition of German Nutrition Society, Bonn, Germany
- Department of Nutrition and Home Economics, University of Applied Science Hamburg, Hamburg, Germany
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12
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Roriz M, Brito P, Teixeira FJ, Brito J, Teixeira VH. Performance effects of internal pre- and per-cooling across different exercise and environmental conditions: A systematic review. Front Nutr 2022; 9:959516. [PMID: 36337635 PMCID: PMC9632747 DOI: 10.3389/fnut.2022.959516] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/19/2022] [Indexed: 11/13/2022] Open
Abstract
Exercise in a hot and humid environment may endanger athlete's health and affect physical performance. This systematic review aimed to examine whether internal administration of ice, cold beverages or menthol solutions may be beneficial for physical performance when exercising in different environmental conditions and sports backgrounds. A systematic search was performed in PubMed, Web of Science, Scopus and SPORTDiscus databases, from inception to April 2022, to identify studies meeting the following inclusion criteria: healthy male and female physically active individuals or athletes (aged ≥18 years); an intervention consisting in the internal administration (i.e., ingestion or mouth rinse) of ice slush, ice slurry or crushed ice and/or cold beverages and/or menthol solutions before and/or during exercise; a randomized crossover design with a control or placebo condition; the report of at least one physical performance outcome; and to be written in English. Our search retrieved 2,714 articles in total; after selection, 43 studies were considered, including 472 participants, 408 men and 64 women, aged 18-42 years, with a VO2max ranging from 46.2 to 67.2 mL⋅kg-1⋅min-1. Average ambient temperature and relative humidity during the exercise tasks were 32.4 ± 3.5°C (ranging from 22°C to 38°C) and 50.8 ± 13.4% (varying from 20.0% to 80.0%), respectively. Across the 43 studies, 7 exclusively included a menthol solution mouth rinse, 30 exclusively involved ice slurry/ice slush/crushed ice/cold beverages intake, and 6 examined both the effect of thermal and non-thermal internal techniques in the same protocol. Rinsing a menthol solution (0.01%) improved physical performance during continuous endurance exercise in the heat. Conversely, the ingestion of ice or cold beverages did not seem to consistently increase performance, being more likely to improve performance in continuous endurance trials, especially when consumed during exercises. Co-administration of menthol with or within ice beverages seems to exert a synergistic effect by improving physical performance. Even in environmental conditions that are not extreme, internal cooling strategies may have an ergogenic effect. Further studies exploring both intermittent and outdoor exercise protocols, involving elite male and female athletes and performed under not extreme environmental conditions are warranted. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021268197], identifier [CRD42021268197].
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Affiliation(s)
- Maria Roriz
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
- Futebol Clube do Porto, Porto, Portugal
| | - Pedro Brito
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Maia, ISMAI, Maia, Portugal
| | - Filipe J. Teixeira
- Interdisciplinary Center for the Study of Human Performance (CIPER), Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz-Quebrada, Portugal
- Atlântica, Instituto Universitário, Fábrica da Pólvora de Barcarena, Barcarena, Portugal
- Bettery Lifelab, Bettery S.A., Lisbon, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation, Oeiras, Portugal
| | - Vitor Hugo Teixeira
- Faculty of Nutrition and Food Sciences, University of Porto (FCNAUP), Porto, Portugal
- Futebol Clube do Porto, Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
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13
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Büchner K, Haagen J, Sastrosubroto A, Kerpes R, Freiherr J, Becker T. Trigeminal Stimulus Menthol Masks Bitter Off-Flavor of Artificial Sweetener Acesulfame-K. Foods 2022; 11:foods11182734. [PMID: 36140868 PMCID: PMC9497717 DOI: 10.3390/foods11182734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/02/2022] [Indexed: 12/01/2022] Open
Abstract
Consumer health concerns and regulatory policies lead to a growing demand for sugar-sweetened beverage alternatives. A reduced energy content can be achieved using artificial sweeteners, which often also convey a metallic or bitter off-flavor. Therefore, the alteration of sweetness perception and masking of potential off-flavors are paramount for improving sweet beverages. Trigeminal stimuli, such as capsaicin (spicy) or menthol (cooling), have been used to influence taste perception in food items, although their use in beverages has not yet been systematically investigated. Here, the influence of menthol on sweetness perception in an aqueous solution is examined both on the sensory and psychophysiological level. The addition of menthol had no sensory effect on sweetness perception; however, psychophysiological measurements suggest a boost in the physiological response to cold perception through the addition of sugar. Moreover, menthol addition shifted the recognition threshold of unpleasant bitterness of the sweetener acesulfame-K from 21.35 to 36.93 mg/L, masking the off-flavor. These findings illuminate the complexity of trigeminal perception influences on taste. Further investigation of these effects can render trigeminal stimuli an effective tool to enhance beverage aroma and flavor.
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Affiliation(s)
- Kai Büchner
- Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology, Technical University of Munich, Weihenstephaner Steig 20, 85354 Freising, Germany
| | - Jana Haagen
- Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology, Technical University of Munich, Weihenstephaner Steig 20, 85354 Freising, Germany
- Sensory Analytics and Technologies, Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany
| | - Ashtri Sastrosubroto
- Sensory Analytics and Technologies, Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany
| | - Roland Kerpes
- Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology, Technical University of Munich, Weihenstephaner Steig 20, 85354 Freising, Germany
- Correspondence: ; Tel.: +49-8161-71-3277
| | - Jessica Freiherr
- Sensory Analytics and Technologies, Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Thomas Becker
- Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology, Technical University of Munich, Weihenstephaner Steig 20, 85354 Freising, Germany
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14
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Bartolomei S, Nigro F, D'Amico A, Cortesi M, Di Michele R. Mud Pack With Menthol and Arnica Montana Accelerates Recovery Following a High-Volume Resistance Training Session for Lower Body in Trained Men. J Strength Cond Res 2022; 36:1909-1915. [PMID: 32956264 PMCID: PMC10842651 DOI: 10.1519/jsc.0000000000003751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Bartolomei, S, Nigro, F, D'Amico, A, Cortesi, M, and Di Michele, R. Mud pack with menthol and Arnica montana accelerates recovery following a high-volume resistance training session for lower body in trained men. J Strength Cond Res 36(7): 1909-1915, 2022-The aim of this study was to compare the effects of a mud pack, containing menthol and Arnica montana, on the recovery responses following a high-volume resistance protocol. Ten resistance-trained men (mean ± SD: age = 25.3 ± 6.1 years; body mass = 79.1 ± 10.6 kg; height = 178.9 ± 7.5 cm) performed a high-volume resistance workout for lower body squat and leg extension, (5 sets of 10 reps at 70% of one repetition maximum for both exercises). All the subject used mud (MUD) or a placebo (PL) in randomized counterbalanced crossover design. MUD or PL were applied 4 times: 3, 19, 27, and 45 hours after the workout, on the skin surface above the quadriceps muscle of both legs. Muscle performance (countermovement jump power [CMJP], isokinetic leg press at 75 cm·s-1 and 25 cm·s-1 [ISOK75 and ISOK25, respectively], isometric squat [ISQ]), and morphology (muscle thickness of vastus lateralis [VLMT]), were measured before exercise (baseline [BL]), and 15 minutes (15P), 24 hours (24P), and 48 hours (48P) postexercise. In addition, muscle soreness was assessed at the same time points using a visual analog scale (VAS). No significant interactions (p > 0.05) between the trials were detected for CMJP, ISOK75, ISQ, and VLMT. A significant interaction between trials was noted for ISOK25 (p = 0.022) and for VAS (p = 0.001). ISOK25 was significantly (p < 0.01) reduced from BL at 15P, 24P and 48P in PL, whereas changes were significant (p < 0.05) at 15P and 24P only in MUD. The present findings indicate that MUD may enhance the recovery rate of strength and reduce muscle soreness after high-volume exercise. Muscle morphology do not seem to be influenced by mud packs.
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Affiliation(s)
- Sandro Bartolomei
- Department of Biomedical and Neuoromotor Sciences, University of Bologna, Bologna, Italy; and
| | - Federico Nigro
- Department for Life Quality Studies, University of Bologna, Bologna, Italy
| | - Alessio D'Amico
- Department for Life Quality Studies, University of Bologna, Bologna, Italy
| | - Matteo Cortesi
- Department for Life Quality Studies, University of Bologna, Bologna, Italy
| | - Rocco Di Michele
- Department of Biomedical and Neuoromotor Sciences, University of Bologna, Bologna, Italy; and
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15
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Crosby S, Butcher A, McDonald K, Berger N, Bekker PJ, Best R. Menthol Mouth Rinsing Maintains Relative Power Production during Three-Minute Maximal Cycling Performance in the Heat Compared to Cold Water and Placebo Rinsing. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063527. [PMID: 35329209 PMCID: PMC8949398 DOI: 10.3390/ijerph19063527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/07/2022] [Accepted: 03/13/2022] [Indexed: 11/16/2022]
Abstract
Previous menthol studies have demonstrated ergogenic effects in endurance-based activity. However, there is a need for research in sports whose physiological requirements exceed maximal aerobic capacity. This study assessed the effects of 0.1% menthol mouth-rinsing upon a modified three-minute maximal test in the heat (33.0 ± 3.0 °C; RH 46.0 ± 5.0%). In a randomised crossover single blind placebo-controlled study, 11 participants completed three modified maximal tests, where each trial included a different mouth rinse: either menthol (MEN), cold water (WAT) or placebo (PLA). Participants were asked to rate their thermal comfort (TC), thermal sensation (TS) and rating of perceived exertion (RPE) throughout the test. Heart rate, core temperature, oxygen uptake (VO2), ventilation (VE) and respiratory exchange ratio (RER) were monitored continuously throughout the test, alongside cycling power variables (W; W/kg). A blood lactate (BLa) level was taken pre- and post- test. Small to moderate effects (Cohen's d and accompanying 90% confidence intervals) between solutions MEN, WAT and PLA were observed towards the end of the test in relation to relative power. Specifically, from 75-105 s between solutions MEN and WAT (ES: 0.795; 90% CI: 0.204 to 1.352) and MEN and PLA (ES: 1.059; 90% CI: 0.412 to 1.666), this continued between MEN and WAT (ES: 0.729; 90% CI: 0.152 to 1.276) and MEN and PLA (ES: 0.791; 90% CI: 0.202 to 1.348) from 105-135 s. Between 135-165 s there was a moderate difference between solutions MEN and WAT (ES: 1.058; 90% CI: 0.411 to 1.665). This indicates participants produced higher relative power for longer durations with the addition of the menthol mouth rinse, compared to cold water or placebo. The use of menthol (0.1%) as a mouth rinse showed small performance benefits for short duration high intensity exercise in the heat.
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Affiliation(s)
- Seana Crosby
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (A.B.); (K.M.); (P.J.B.)
| | - Anna Butcher
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (A.B.); (K.M.); (P.J.B.)
| | - Kerin McDonald
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (A.B.); (K.M.); (P.J.B.)
| | - Nicolas Berger
- School of Health and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK;
| | - Petrus J. Bekker
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (A.B.); (K.M.); (P.J.B.)
| | - Russ Best
- Centre for Sport Science & Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (A.B.); (K.M.); (P.J.B.)
- Correspondence:
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16
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Bajagai YS, Petranyi F, Horyanto D, Batacan R, Lobo E, Ren X, Whitton MM, Yu SJ, Kayal A, Stanley D. Ileum transcriptional response to prolonged supplementation with phytogenic product containing menthol, carvacrol and carvone. Heliyon 2022; 8:e09131. [PMID: 35345405 PMCID: PMC8956889 DOI: 10.1016/j.heliyon.2022.e09131] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/28/2022] [Accepted: 03/15/2022] [Indexed: 12/29/2022] Open
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17
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Best R, Crosby S, Berger N, McDonald K. The Effect of Isolated and Combined Application of Menthol and Carbohydrate Mouth Rinses on 40 km Time Trial Performance, Physiological and Perceptual Measures in the Heat. Nutrients 2021; 13:4309. [PMID: 34959861 PMCID: PMC8708984 DOI: 10.3390/nu13124309] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/24/2021] [Accepted: 11/28/2021] [Indexed: 01/31/2023] Open
Abstract
The current study compared mouth swills containing carbohydrate (CHO), menthol (MEN) or a combination (BOTH) on 40 km cycling time trial (TT) performance in the heat (32 °C, 40% humidity, 1000 W radiant load) and investigates associated physiological (rectal temperature (Trec), heart rate (HR)) and subjective measures (thermal comfort (TC), thermal sensation (TS), thirst, oral cooling (OC) and RPE (legs and lungs)). Eight recreationally trained male cyclists (32 ± 9 y; height: 180.9 ± 7.0 cm; weight: 76.3 ± 10.4 kg) completed familiarisation and three experimental trials, swilling either MEN, CHO or BOTH at 10 km intervals (5, 15, 25, 35 km). The 40 km TT performance did not differ significantly between conditions (F2,14 = 0.343; p = 0.715; η2 = 0.047), yet post-hoc testing indicated small differences between MEN and CHO (d = 0.225) and MEN and BOTH (d = 0.275). Subjective measures (TC, TS, RPE) were significantly affected by distance but showed no significant differences between solutions. Within-subject analysis found significant interactions between solution and location upon OC intensity (F28,196 = 2.577; p < 0.001; η2 = 0.269). While solutions containing MEN resulted in a greater sensation of OC, solutions containing CHO experienced small improvements in TT performance. Stimulation of central CHO pathways during self-paced cycling TT in the heat may be of more importance to performance than perceptual cooling interventions. However, no detrimental effects are seen when interventions are combined.
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Affiliation(s)
- Russ Best
- Centre for Sports Science and Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (K.M.)
| | - Seana Crosby
- Centre for Sports Science and Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (K.M.)
| | - Nicolas Berger
- School of Health and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK;
| | - Kerin McDonald
- Centre for Sports Science and Human Performance, Waikato Institute of Technology, Hamilton 3200, New Zealand; (S.C.); (K.M.)
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18
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Nutritional Considerations for Para-Cycling Athletes: A Narrative Review. Sports (Basel) 2021; 9:sports9110154. [PMID: 34822353 PMCID: PMC8625771 DOI: 10.3390/sports9110154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/09/2021] [Accepted: 11/11/2021] [Indexed: 01/19/2023] Open
Abstract
Para-cycling is a sport including athletes with different disabilities competing on the track and on the roads using bicycles, tandems, tricycles, and handbikes. Scientific literature in this special population is scarce, especially in the field of sports nutrition. This review summarizes the physiological aspects and demands of para-cycling. This information together with the existing literature on nutritional interventions in this population, helps to discuss the nutritional considerations. To date, only a limited amount of recommendations are available for this population. In most para-cycling athletes, a reduction in active muscle mass and consequently a reduction in resting energy expenditure occurs, except for visually impaired athletes. Furthermore, carbohydrate and protein intake and hydration, supplementation, heat, and weight loss need to be tailored to the disability-specific adaptations such as the reduced active muscle mass, neurogenic bladder, and bowel, a reduced metabolic cost during exercise, and a higher risk of micronutrient deficiency.
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19
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Burke LM. Nutritional approaches to counter performance constraints in high-level sports competition. Exp Physiol 2021; 106:2304-2323. [PMID: 34762329 PMCID: PMC9299184 DOI: 10.1113/ep088188] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/03/2021] [Indexed: 12/12/2022]
Abstract
New Findings What is the topic of this review? The nutritional strategies that athletes use during competition events to optimize performance and the reasons they use them. What advances does it highlight? A range of nutritional strategies can be used by competitive athletes, alone or in combination, to address various event‐specific factors that constrain event performance. Evidence for such practices is constantly evolving but must be combined with understanding of the complexities of real‐life sport for optimal implementation.
Abstract High‐performance athletes share a common goal despite the unique nature of their sport: to pace or manage their performance to achieve the highest sustainable outputs over the duration of the event. Periodic or sustained decline in the optimal performance of event tasks, involves an interplay between central and peripheral phenomena that can often be reduced or delayed in onset by nutritional strategies. Contemporary nutrition practices undertaken before, during or between events include strategies to ensure the availability of limited muscle fuel stores. This includes creatine supplementation to increase muscle phosphocreatine content and consideration of the type, amount and timing of dietary carbohydrate intake to optimize muscle and liver glycogen stores or to provide additional exogenous substrate. Although there is interest in ketogenic low‐carbohydrate high‐fat diets and exogenous ketone supplements to provide alternative fuels to spare muscle carbohydrate use, present evidence suggests a limited utility of these strategies. Mouth sensing of a range of food tastants (e.g., carbohydrate, quinine, menthol, caffeine, fluid, acetic acid) may provide a central nervous system derived boost to sports performance. Finally, despite decades of research on hypohydration and exercise capacity, there is still contention around their effect on sports performance and the best guidance around hydration for sporting events. A unifying model proposes that some scenarios require personalized fluid plans while others might be managed by an ad hoc approach (ad libitum or thirst‐driven drinking) to fluid intake.
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Affiliation(s)
- Louise M Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
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20
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Podlogar T, Bolčič T, Cirnski S, Verdel N, Debevec T. Commercially available carbohydrate drink with menthol fails to improve thermal perception or cycling exercise capacity in males. Eur J Sport Sci 2021; 22:1705-1713. [PMID: 34559601 DOI: 10.1080/17461391.2021.1986140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The purpose of this double-blinded, crossover randomized and counterbalanced study was to compare the effects of ingesting a tepid commercially available carbohydrate-menthol-containing sports drink (menthol) and an isocaloric carbohydrate-containing sports drink (placebo) on thermal perception and cycling endurance capacity "in a simulated home virtual cycling environment". It was hypothesized that the addition of menthol would improve indicators of thermal perception and improve endurance exercise capacity. Twelve healthy, endurance-trained males (age 29 ± 5 years, height 181 ± 6 cm, body mass 79 ± 2 kg and V̇O2max 57.3 ± 6.4 mL kg-1 min-1) completed two experimental trials on a stationary bicycle without external air flow. Each trial consisted of (1) cycling for 60 min at 90% of the first ventilatory threshold while receiving a fixed amount of menthol or placebo every 10 min followed immediately by (2) cycling until volitional exhaustion (TTE) at 105% of the intensity corresponding to the respiratory compensation point. TTE did not differ between both conditions (541 ± 177 and 566 ± 150 s for menthol and placebo; p > 0.05) and neither did ratings of perceived thermal comfort or thermal sensation (p > 0.05). Also, the rectal temperature at the end of TTE was comparable between menthol and placebo trials (38.7 ± 0.2°C and 38.7 ± 0.3°C, respectively; p > 0.05). The present results demonstrate that the addition of menthol to commercially available sports drink does not improve thermal comfort or endurance exercise capacity during ∼65 min of intense virtual cycling.
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Affiliation(s)
- Tim Podlogar
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Health Sciences, University of Primorska, Izola, Slovenia
| | - Tina Bolčič
- Faculty of Sports, University of Ljubljana, Ljubljana, Slovenia
| | | | - Nina Verdel
- Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Sports, University of Ljubljana, Ljubljana, Slovenia
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21
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Effects of 24 h Compression Interventions with Different Garments on Recovery Markers during Running. Life (Basel) 2021; 11:life11090905. [PMID: 34575054 PMCID: PMC8471437 DOI: 10.3390/life11090905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
Compression and temperature manipulation are discussed as strategies to improve performance markers and recovery in sports. Here, we investigate the effects of compression stockings made with fabric, either combined or not with heating and cooling substances, on variables related to running performance and recovery. Ten trained runners (mean ± standard deviation age 45 ± 9 years old, body mass 69 ± 7 kg, height 166 ± 4 cm) with no experience of using compression garments performed an intense running session of 10 km, then wore a stocking for 24 h (randomized; without compression, compression, compression with camphor, and compression with menthol), and were evaluated on the following day, after running 5 km. The different types of compression stockings used 24 h before exercise did not affect running kinematics (p > 0.14), skin temperature (p > 0.05), heart rate (p > 0.12; mean value of maximal heart rate 156 bpm), comfort perception (p = 0.13; mean value of 7/10 points), or perception of recovery (p = 0.13; mean value of 7/10 points). In general, there were no effects of 24 h pre-exercise lower leg compression, including those treated with menthol and camphor applications on running kinematics, skin temperature, heart rate, or recovery perception in athletes undertaking consecutive running exercises.
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Gavel EH, Hawke KV, Bentley DJ, Logan-Sprenger HM. Menthol Mouth Rinsing Is More Than Just a Mouth Wash-Swilling of Menthol to Improve Physiological Performance. Front Nutr 2021; 8:691695. [PMID: 34307438 PMCID: PMC8292615 DOI: 10.3389/fnut.2021.691695] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/10/2021] [Indexed: 01/13/2023] Open
Abstract
Interventions that solely act on the central nervous system (CNS) are gaining considerable interest, particularly products consumed through the oral cavity. The oropharyngeal cavity contains a wide array of receptors that respond to sweet, bitter, and cold tastants, all of which have been shown to improve physiological performance. Of late, the ergogenic benefits of carbohydrate (CHO) and caffeine (CAF) mouth rinsings (MRs) have been widely studied; however, less is known about menthol (MEN). That the physiological state and environmental conditions impact the response each product has is increasingly recognized. While the effects of CHO and CAF MRs have been thoroughly studied in both hot and thermoneutral conditions, less is known about MEN as it has only been studied in hot environments. As such, this review summarizes the current knowledge regarding the MEN MR and exercise modality, frequency of the mouth rinse, and mouth rinse duration and compares two different types of study designs: time trials vs. time to exhaustion (TTE).
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Affiliation(s)
- Erica H Gavel
- Faculty of Science, Ontario Tech University, Oshawa, ON, Canada
| | - Kierstyn V Hawke
- Faculty of Health Science, Ontario Tech University, Oshawa, ON, Canada
| | - David J Bentley
- Faculty of Health Science, Ontario Tech University, Oshawa, ON, Canada
| | - Heather M Logan-Sprenger
- Faculty of Science, Ontario Tech University, Oshawa, ON, Canada.,Faculty of Health Science, Ontario Tech University, Oshawa, ON, Canada.,Canadian Sport Institute Ontario, Toronto, ON, Canada
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23
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Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 127] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
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Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Menthol Mouth Rinsing and Cycling Performance in Females Under Heat Stress. Int J Sports Physiol Perform 2021; 16:1014-1020. [PMID: 33662928 DOI: 10.1123/ijspp.2020-0414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE The effects of menthol (MEN) mouth rinse (MR) on performance, physiological, and perceptual variables in female cyclists during a 30-km independent time trial (ITT) were tested. METHODS The participants (n = 9) cycled for 30 km in hot conditions (30°C [0.6°C], 70% [1%] relative humidity, 12 [1] km/h wind speed) on 2 test occasions: with a placebo MR and with MEN MR. Handgrip and a 5-second sprint were measured before, following the first MR, and after the ITT. Ratings of perceived exertion Borg 6 to 20, thermal sensation, and thermal pleasantness were recorded every 5 km. Core temperature and heart rate were recorded throughout. RESULTS The ITT performance significantly improved with MEN MR by 2.3% (2.7%) relative to the placebo (62.6 [5.7] vs 64.0 [4.9] min P = .034; d = 0.85; 95% confidence interval, 0.14 to 2.8 min). The average power output was significantly higher in the MEN trial (P = .031; d = 0.87; 95% confidence interval, 0.9 to 15.0 W). No significant interaction of time and MR for handgrip (P = .581, η2 = .04) or sprint was observed (P = .365, η2 = .103). Core temperature, heart rate, ratings of perceived exertion, and thermal sensation did not significantly differ between trials at set distances (P > .05). Pleasantness significantly differed between the placebo and MEN only at 5 km, with no differences at other TT distances. CONCLUSION These results suggest that a nonthermal cooling agent can improve 30-km ITT performance in female cyclists, although the improved performance with MEN MR is not due to altered thermal perception.
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External Loading Characteristics of Polo Ponies and Corresponding Player Heart Rate Responses in 16-Goal Polo. J Equine Vet Sci 2021; 98:103368. [PMID: 33663720 DOI: 10.1016/j.jevs.2020.103368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/25/2020] [Accepted: 12/22/2020] [Indexed: 11/23/2022]
Abstract
When compared with other equestrian sports, Polo players engage in a high number of player-pony interactions. To ensure optimal performance of the player-pony dyad, an understanding of the workloads performed by each pony and the physiological cost placed on the rider are required. This investigation examined the relationship and interaction between Polo pony performance (speeds attained, distance covered, and movements performed) and the corresponding heart rate responses in Polo players, within and between games across a 16-goal Polo tournament. Descriptive statistics revealed Polo is played at an intensity that imposes considerable cardiovascular exertion, with players' average heart rate (HRavg) and maximum heart rate (HRmax) frequently exceeding 165 bpm and 200 bpm, respectively, within most games. Data also demonstrated that both HRavg and HRmax have small to moderate relationships (P < .05) with numerous discrete measures of pony external workload, especially, pony accelerations, decelerations, impacts, and sprints. These findings highlight the chukka and game-specific interactions between pony actions and the players' cardiovascular responses to these movements. If the cardiovascular conditioning of the player is insufficient to meet the demands of Polo play, the combined performance of the player-pony dyad may be limited.
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26
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Hedge ET, Zuj KA, Stothart AG, Gavel EH, Goodman LS, Buckrell AJM, Peterson SD. Continuous forearm cooling attenuates gastrointestinal temperature increase during cycling. J Sports Sci 2020; 39:542-551. [PMID: 33200649 DOI: 10.1080/02640414.2020.1835222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Hot environmental conditions can challenge thermoregulation resulting in exacerbated heat strain. This study evaluated the influence of continuous inner forearm cooling on gastrointestinal temperature (TGI) and physiological responses to exercise in hot (30°C) and humid (relative humidity: 70%) conditions. Eleven trained cyclists (seven male age: 37±12 years; four female age: 41±15 years; mean±standard deviation) performed two experimental trials, cycling at 66% of their self-reported functional threshold power (average work rate over an hour of maximum effort cycling; 175±34W) for 45 minutes in an environmental chamber. One trial employed continuous inner forearm cooling (COOL) with 5°C water passing through aluminum heat exchangers, while the other had no cooling (CONTROL). Heat was removed from the body at an average rate of 30.3±6.6W during the COOL trial resulting in an attenuation of TGI rise (CONTROL: 2.46±0.70, COOL: 2.03±0.63°C·h-1; p=0.002). The change in heart rate from the 10th minute to the end of exercise, as an indicator of cardiovascular drift, was reduced (CONTROL: 20±7, COOL: 17±6beats·min-1; p=0.050) and end-exercise thermal comfort was improved in the COOL trial with a trend for reduced rating of perceived exertion (p=0.055). Findings suggest that continuous cooling of the inner forearms can attenuate the rise of TGI and help mitigate the risk of heat injury during exercise in hot and humid conditions.
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Affiliation(s)
- Eric T Hedge
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Kathryn A Zuj
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Alexander G Stothart
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Erica H Gavel
- Kinesiology & Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Len S Goodman
- Defence Research and Development Canada, Toronto Research Centre, Toronto, Ontario, Canada
| | - Andrew J M Buckrell
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada.,4iiii Innovations Inc., Cochrane, Alberta, Canada
| | - Sean D Peterson
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
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Parton AJ, Waldron M, Clifford T, Jeffries O. Thermo-behavioural responses to orally applied l-menthol exhibit sex-specific differences during exercise in a hot environment. Physiol Behav 2020; 229:113250. [PMID: 33220326 DOI: 10.1016/j.physbeh.2020.113250] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/29/2020] [Accepted: 11/16/2020] [Indexed: 10/23/2022]
Abstract
AIMS This study investigated the efficacy of l-menthol mouth-rinsing on thermal sensation and perceived effort in females and males, using a fixed-rating of perceived exertion (RPE) exercise protocol in a hot environment. METHODS Twenty-two participants (eleven females, eleven males) completed two trials using a fixed-RPE protocol at an exercise intensity between 'hard' and 'very hard', equating to 16 on the RPE scale at ~35 °C. Participants adjusted power output to maintain RPE-16. In a randomised, double-blind, crossover design, l-menthol or a control mouthwash was administered at an orally neutral temperature (~32 °C) prior to exercise and at 10 min intervals thereafter. Measures of mechanical power output, core temperature, heart rate, perception of thermal sensation and thermal comfort, and whole-body sweat loss are reported. RESULTS Thermal sensation was lowered by l-menthol in both sexes (P < 0.05), however during exercise this was only maintained for 40% of the trial duration in females. Thermal comfort did not differ between conditions (P > 0.05). No differences in exercise duration were observed compared to control, despite a ~4% and ~6% increase in male and females respectively. Power output increased by ~6.5% males (P = 0.039) with no difference in females ~2.2% (P = 0.475), compared to control. Core temperature, heart rate and whole-body sweat loss was not different between condition or sex. CONCLUSIONS l-menthol lowered perceptual measures of thermal sensation in females, but did not attenuate a greater rate of rise in thermal sensitivity when exercising in a hot environment, compared to males. Males appeared to adopt a higher risk strategy by increasing power output following l-menthol administration in contrast to a more conservative pacing strategy in females. Therefore, there appear to be sex-specific differences in l-menthol's non-thermal cooling properties and subsequent effects on thermo-behavioural adjustments in work-load when exercising in a hot environment.
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Affiliation(s)
- Abbie Jayne Parton
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Mark Waldron
- College of Engineering, Swansea University, Swansea, United Kingdom; School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - Tom Clifford
- School of Sport, Health and Exercise Sciences, Loughborough University, Loughborough, United Kingdom
| | - Owen Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom.
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Denby K, Caruso R, Schlicht E, Ives SJ. The Impact of Wrist Percooling on Physiological and Perceptual Responses during a Running Time Trial Performance in the Heat. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17207559. [PMID: 33080833 PMCID: PMC7590038 DOI: 10.3390/ijerph17207559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 11/16/2022]
Abstract
Environmental heat stress poses significant physiological challenge and impairs exercise performance. We investigated the impact of wrist percooling on running performance and physiological and perceptual responses in the heat. In a counterbalanced design, 13 trained males (33 ± 9 years, 15 ± 7% body fat, and maximal oxygen consumption, VO2max 59 ± 5 mL/kg/min) completed three 10 km running time trials (27 °C, 60% relative humidity) while wearing two cooling bands: (1) both bands were off (off/off), (2) one band on (off/on), (3) both bands on (on/on). Heart rate (HR), HR variability (HRV), mean arterial pressure (MAP), core temperature (TCO), thermal sensation (TS), and fatigue (VAS) were recorded at baseline and recovery, while running speed (RS) and rating of perceived exertion (RPE) were collected during the 10 km. Wrist cooling had no effect (p > 0.05) at rest, except modestly increased HR (3-5 ∆beats/min, p < 0.05). Wrist percooling increased (p < 0.05) RS (0.25 ∆mi/h) and HR (5 ∆beats/min), but not TCO (∆ 0.3 °C), RPE, or TS. Given incomplete trials, the distance achieved at 16 min was not different between conditions (off/off 1.96 ± 0.16 vs. off/on 1.98 ± 0.19 vs. on/on 1.99 ± 0.24 miles, p = 0.490). During recovery HRV, MAP, or fatigue were unaffected (p > 0.05). We demonstrate that wrist percooling elicited a faster running speed, though this coincides with increased HR; although, interestingly, sensations of effort and thermal comfort were unaffected, despite the faster speed and higher HR.
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Barwood MJ, Gibson OR, Gillis DJ, Jeffries O, Morris NB, Pearce J, Ross ML, Stevens C, Rinaldi K, Kounalakis SN, Riera F, Mündel T, Waldron M, Best R. Menthol as an Ergogenic Aid for the Tokyo 2021 Olympic Games: An Expert-Led Consensus Statement Using the Modified Delphi Method. Sports Med 2020; 50:1709-1727. [PMID: 32623642 PMCID: PMC7497433 DOI: 10.1007/s40279-020-01313-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Menthol topical application and mouth rinsing are ergogenic in hot environments, improving performance and perception, with differing effects on body temperature regulation. Consequently, athletes and federations are beginning to explore the possible benefits to elite sport performance for the Tokyo 2021 Olympics, which will take place in hot (~ 31 °C), humid (70% RH) conditions. There is no clear consensus on safe and effective menthol use for athletes, practitioners, or researchers. The present study addressed this shortfall by producing expert-led consensus recommendations. METHOD Fourteen contributors were recruited following ethical approval. A three-step modified Delphi method was used for voting on 96 statements generated following literature consultation; 192 statements total (96/96 topical application/mouth rinsing). Round 1 contributors voted to "agree" or "disagree" with statements; 80% agreement was required to accept statements. In round 2, contributors voted to "support" or "change" their round 1 unaccepted statements, with knowledge of the extant voting from round 1. Round 3 contributors met to discuss voting against key remaining statements. RESULTS Forty-seven statements reached consensus in round 1 (30/17 topical application/rinsing); 14 proved redundant. Six statements reached consensus in round 2 (2/4 topical application/rinsing); 116 statements proved redundant. Nine further statements were agreed in round 3 (6/3 topical application/rinsing) with caveats. DISCUSSION Consensus was reached on 62 statements in total (38/24 topical application/rinsing), enabling the development of guidance on safe menthol administration, with a view to enhancing performance and perception in the heat without impairing body temperature regulation.
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Affiliation(s)
- M J Barwood
- Department of Sport, Health and Nutrition, Leeds Trinity University, Brownberrie Lane, Horsforth, Leeds, LS18 5HD, UK.
| | - O R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Department Life Sciences, Division of Sport, Health and Exercise Sciences, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - D J Gillis
- Human Performance Laboratory, Department of Sport and Movement Science, Salem State University, Salem, MA, 01970, USA
| | - O Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Faculty of Medical Sciences, Newcastle University, Catherine Cookson Building, Newcastle Upon Tyne, NE2 4HH, UK
| | - N B Morris
- Department of Nutrition, Exercise and Sports, University of Copenhagen, 2100, Copenhagen, Denmark
| | - J Pearce
- Performance Nutrition Technical Lead, High Performance Sport New Zealand, Auckland, New Zealand
| | - M L Ross
- Australian Institute of Sport, Bruce, 2617, Australia
- Mary Mackillop Institute for Health Research, Australian Catholic University, Melbourne, 3000, Australia
| | - C Stevens
- School of Health and Human Sciences, Southern Cross University, Hogbin Dr, Coffs Harbour, NSW, 2450, Australia
| | - K Rinaldi
- Laboratoire ACTES (EA3596), Université des Antilles et de la Guyane, BP 250, 97157, Pointe-à-Pitre, France
- Arkea Samsic Pro Cycling Team, 35170, Bruz, France
| | - S N Kounalakis
- Faculty of Physical and Cultural Education, Evelpidon Hellenic Army Academy, Vari, Greece
| | - F Riera
- UPRES EA 35-96, UFR-STAPS, Université des Antilles et de la Guyane, BP 250, 97157, Pointe à Pitre Cedex, France
- Laboratoire Performance Santé Altitude, Université de Perpignan Via Domitia, UFR Sciences et Techniques des Activités Physiques et Sportives, 7 avenue Pierre de Coubertin, 66120, Font-Romeu, France
| | - T Mündel
- School of Sport Exercise and Nutrition, Massey University, Palmerston, New Zealand
| | - M Waldron
- College of Engineering, Applied Sports Science Technology and Medicine Research Centre (A-STEM), Swansea University Bay Campus, Swansea, Wales, UK
- School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - R Best
- Centre for Sport Science and Human Performance, Waikato Institute of Technology, Hamilton, 3200, New Zealand
- School of Health and Social Care, Teesside University, Middlesbrough, Tees Valley, TS1 3BX, UK
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Morris NB, Jay O, Flouris AD, Casanueva A, Gao C, Foster J, Havenith G, Nybo L. Sustainable solutions to mitigate occupational heat strain - an umbrella review of physiological effects and global health perspectives. Environ Health 2020; 19:95. [PMID: 32887627 PMCID: PMC7487490 DOI: 10.1186/s12940-020-00641-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/12/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Climate change is set to exacerbate occupational heat strain, the combined effect of environmental and internal heat stress on the body, threatening human health and wellbeing. Therefore, identifying effective, affordable, feasible and sustainable solutions to mitigate the negative effects on worker health and productivity, is an increasingly urgent need. OBJECTIVES To systematically identify and evaluate methods that mitigate occupational heat strain in order to provide scientific-based guidance for practitioners. METHODS An umbrella review was conducted in biomedical databases employing the following eligibility criteria: 1) ambient temperatures > 28 °C or hypohydrated participants, 2) healthy adults, 3) reported psychophysiological (thermal comfort, heart rate or core temperature) and/or performance (physical or cognitive) outcomes, 4) written in English, and 5) published before November 6, 2019. A second search for original research articles was performed to identify interventions of relevance but lacking systematic reviews. All identified interventions were independently evaluated by all co-authors on four point scales for effectiveness, cost, feasibility and environmental impact. RESULTS Following screening, 36 systematic reviews fulfilled the inclusion criteria. The most effective solutions at mitigating occupational heat strain were wearing specialized cooling garments, (physiological) heat acclimation, improving aerobic fitness, cold water immersion, and applying ventilation. Although air-conditioning and cooling garments in ideal settings provide best scores for effectiveness, the limited applicability in certain industrial settings, high economic cost and high environmental impact are drawbacks for these solutions. However, (physiological) acclimatization, planned breaks, shading and optimized clothing properties are attractive alternative solutions when economic and ecological sustainability aspects are included in the overall evaluation. DISCUSSION Choosing the most effective solution or combinations of methods to mitigate occupational heat strain will be scenario-specific. However, this paper provides a framework for integrating effectiveness, cost, feasibility (indoors and outdoor) and ecologic sustainability to provide occupational health and safety professionals with evidence-based guidelines.
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Affiliation(s)
- Nathan B. Morris
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Denmark
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Andreas D. Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Ana Casanueva
- Federal Office of Meteorology and Climatology, MeteoSwiss, Zurich Airport, Zurich, Switzerland
- Meteorology Group, Department of Applied Mathematics and Computer Sciences, University of Cantabria, Santander, Spain
| | - Chuansi Gao
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund, Sweden
| | - Josh Foster
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough, UK
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Denmark
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Keringer P, Farkas N, Gede N, Hegyi P, Rumbus Z, Lohinai Z, Solymar M, Ruksakiet K, Varga G, Garami A. Menthol can be safely applied to improve thermal perception during physical exercise: a meta-analysis of randomized controlled trials. Sci Rep 2020; 10:13636. [PMID: 32788718 PMCID: PMC7423903 DOI: 10.1038/s41598-020-70499-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/27/2020] [Indexed: 02/03/2023] Open
Abstract
Menthol is often used as a cold-mimicking substance to allegedly enhance performance during physical activity, however menthol-induced activation of cold-defence responses during exercise can intensify heat accumulation in the body. This meta-analysis aimed at studying the effects of menthol on thermal perception and thermophysiological homeostasis during exercise. PubMed, EMBASE, Cochrane Library, and Google Scholar databases were searched until May 2020. Menthol caused cooler thermal sensation by weighted mean difference (WMD) of - 1.65 (95% CI, - 2.96 to - 0.33) and tended to improve thermal comfort (WMD = 1.42; 95% CI, - 0.13 to 2.96) during physical exercise. However, there was no meaningful difference in sweat production (WMD = - 24.10 ml; 95% CI, - 139.59 to 91.39 ml), deep body temperature (WMD = 0.02 °C; 95% CI, - 0.11 to 0.15 °C), and heart rate (WMD = 2.67 bpm; 95% CI - 0.74 to 6.09 bpm) between the treatment groups. Menthol improved the performance time in certain subgroups, which are discussed. Our findings suggest that different factors, viz., external application, warmer environment, and higher body mass index can improve menthol's effects on endurance performance, however menthol does not compromise warmth-defence responses during exercise, thus it can be safely applied by athletes from the thermoregulation point of view.
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Affiliation(s)
- Patrik Keringer
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Nelli Farkas
- Institute for Translational Medicine, Szentagothai Research Centre, Medical School, University of Pecs, 7624, Pecs, Hungary
- Institute of Bioanalysis, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Noemi Gede
- Institute for Translational Medicine, Szentagothai Research Centre, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Peter Hegyi
- Institute for Translational Medicine, Szentagothai Research Centre, Medical School, University of Pecs, 7624, Pecs, Hungary
- Department of Translational Medicine, First Department of Medicine, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Zoltan Rumbus
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Zsolt Lohinai
- Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, 1088, Budapest, Hungary
| | - Margit Solymar
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, 7624, Pecs, Hungary
| | - Kasidid Ruksakiet
- Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, 1088, Budapest, Hungary
- Department of Oral Biology, Faculty of Dentistry, Semmelweis University, 1089, Budapest, Hungary
| | - Gabor Varga
- Department of Oral Biology, Faculty of Dentistry, Semmelweis University, 1089, Budapest, Hungary
| | - Andras Garami
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, 7624, Pecs, Hungary.
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Best R, Temm D, Hucker H, McDonald K. Repeated Menthol Mouth Swilling Affects Neither Strength nor Power Performance. Sports (Basel) 2020; 8:E90. [PMID: 32560472 PMCID: PMC7353636 DOI: 10.3390/sports8060090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/05/2020] [Accepted: 06/16/2020] [Indexed: 01/05/2023] Open
Abstract
This study aimed to assess the effects of repeated menthol mouth swilling upon strength and power performance. Nineteen (10 male) participants completed familiarisation and experimental trials of repeated menthol mouth swilling (0.1% concentration) or control (no swill) in a randomised crossover design. Participants performed an isometric mid-thigh pull (IMTP; peak and mean force; N), vertical jump (peak; cm) and six second sprint (peak and mean power; W) under each condition. Participants completed three efforts per exercise task interspersed with three-minute recoveries. Mean best values were analysed via a two-way mixed repeated measures ANOVA, and differences reported as effect sizes ± 95% confidence intervals, with accompanying descriptors and p values. Differences in peak IMTP values were unclear between familiarisation and experimental trials, and between menthol and control conditions. Mean IMTP force differed between familiarisation and control (0.51; -0.15 to 1.14; p = 0.001) and familiarisation and menthol conditions (0.50; -0.15 to 1.14; p = 0.002) by a small degree, but were unclear between control and menthol conditions. Unclear differences were also noted on vertical jump performance compared to familiarisation and between experimental conditions, with repeated six second peak and average power performance also showing unclear effects across all comparisons. We conclude that repeated menthol mouth swilling does not improve strength or power performance.
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Affiliation(s)
- Russ Best
- Centre for Sport Science and Human Performance, Wintec, Hamilton 3200, New Zealand; (D.T.); (H.H.); (K.M.)
- School of Health and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK
| | - Dani Temm
- Centre for Sport Science and Human Performance, Wintec, Hamilton 3200, New Zealand; (D.T.); (H.H.); (K.M.)
| | - Holly Hucker
- Centre for Sport Science and Human Performance, Wintec, Hamilton 3200, New Zealand; (D.T.); (H.H.); (K.M.)
| | - Kerin McDonald
- Centre for Sport Science and Human Performance, Wintec, Hamilton 3200, New Zealand; (D.T.); (H.H.); (K.M.)
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Abstract
Taste is a homeostatic function that conveys valuable information, such as energy density, readiness to eat, or toxicity of foodstuffs. Taste is not limited to the oral cavity but affects multiple physiological systems. In this review, we outline the ergogenic potential of substances that impart bitter, sweet, hot and cold tastes administered prior to and during exercise performance and whether the ergogenic benefits of taste are attributable to the placebo effect. Carbohydrate mouth rinsing seemingly improves endurance performance, along with a potentially ergogenic effect of oral exposure to both bitter tastants and caffeine although subsequent ingestion of bitter mouth rinses is likely required to enhance performance. Hot and cold tastes may prove beneficial in circumstances where athletes' thermal state may be challenged. Efficacy is not limited to taste, but extends to the stimulation of targeted receptors in the oral cavity and throughout the digestive tract, relaying signals pertaining to energy availability and temperature to appropriate neural centres. Dose, frequency and timing of tastant application likely require personalisation to be most effective, and can be enhanced or confounded by factors that relate to the placebo effect, highlighting taste as a critical factor in designing and administering applied sports science interventions.
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Schneider R. Essential oil inhaler (AromaStick®) improves heat tolerance in the Hot Immersion Test (HIT). Results from two randomized, controlled experiments. J Therm Biol 2019; 87:102478. [PMID: 31999606 DOI: 10.1016/j.jtherbio.2019.102478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/30/2019] [Accepted: 11/28/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND A recent review article on an aromatherapeutic inhaler demonstrated clinical effects on a number of bodily systems, like the cardiovascular system, the respiratory system, the nervous system and the endocrine system. OBJECTIVE This paper extends these findings and investigates whether specially designed essential oils inhalers are capable to counter experimentally induced stressful heat sensations. METHOD Two prospective, randomized, controlled experiments using the Hot Immersion Test Paradigm (HIT) were conducted to investigate whether deep odor inhalations increase heat tolerance. RESULTS In both experiments, the inhaler strongly prolonged pain tolerance and increased blood oxygenation (1 < d < 1.3). In the second experiment, the inhaler also increased heart rate variability (d = 1.3) as a mechanism to cope with heat stress. CONCLUSION The ability to resist a stressful thermal stimulus can be exogenously improved by short and deep inhalations of essential scents directly delivered to the olfactory system.
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Affiliation(s)
- Rainer Schneider
- RECON - Research and Consulting, Unterer Mühlenweg 38B, 79114, Freiburg, Germany.
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Engelhard D, Hofer P, Annaheim S. Evaluation of the effect of cooling strategies on recovery after surgical intervention. BMJ Open Sport Exerc Med 2019; 5:e000527. [PMID: 31275604 PMCID: PMC6579562 DOI: 10.1136/bmjsem-2019-000527] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2019] [Indexed: 01/15/2023] Open
Abstract
Introduction Different cooling strategies exist for emergency treatments immediately after sports trauma or after surgery. The aim of this study was to investigate the effects of three cooling regimen during the immediate postoperative phase as well as in the rehabilitation phase. Methods 36 patients undergoing anterior cruciate ligament reconstruction received either no cooling (control-group, Con, N=12), were cooled with a menthol-containing cooling bandage (Mtl, N=12) or cooled with an ice containing cold pack (CP, N=12). During a 12-week physiotherapy treatment the cross section of the vastus medialis muscle was examined (day—1; 30; 60; 90) and painkiller consumption was documented. Results A significant reduction in the cross section area 30 days after surgery was observed in CP and Con (Mtl: −3.2±1.7%, p=0.14, CP: −8.8±4.3%, p<0.01, Con: −7.2±8.1%, p<0.05). After 90 days of therapy, a significant increase in muscle cross section area was observed in Mtl (Mtl: 4.6%±6.1%, p<0.05, CP: 1.9%± 8.1%, p=0.29, Con: 3.3%±9.4%, p=0.31). The absolute painkiller consumption was lower for Mtl (25.5±3.7 tablets) than for CP (39.5±6.9 tablets) or Con (34.8±4.2 tablets). Conclusion We observed a beneficial effect of cooling by a menthol-containing bandage during the rehabilitation phase. Reduction of muscle cross section within 30 days after surgery was prevented which highly contributed to rehabilitation success after 90 days of therapy. Painkiller consumption was reduced with Mtl.
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Affiliation(s)
| | | | - Simon Annaheim
- Empa, Laboratory for Biomimetic Membranes and Textiles, St. Gallen, Switzerland
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