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Jerram ML, Baker D, Smith TB, Healey P, Taylor L, Black K. A 0.1% L-Menthol Mouth Swill in Elite Male Rugby Players Has Different Effects in Forwards and Backs. Int J Sports Physiol Perform 2023; 18:909-917. [PMID: 36689991 DOI: 10.1123/ijspp.2022-0191] [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: 05/12/2022] [Revised: 09/20/2022] [Accepted: 10/26/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE Menthol mouth swills can improve endurance performance in the heat, which is attributed to attenuations in nonthermally derived thermal sensation (TS) and perception of effort. However, research in elite team-sport athletes is absent. Therefore, this study investigated the performance and TS responses to a 0.1% menthol mouth rinse (MR) or placebo (PLA) among elite male rugby union players. METHOD Twenty-seven (15 Forwards and 12 Backs) elite male Super Rugby players completed two 3-minute 15-a-side rugby-specific conditioning blocks, with MR or PLA provided at the start of training (baseline), at the start of each 3-minute block (swill 1 [S1] and swill 2 [S2]), and at the end of training (swill 3 [S3]). TS was assessed using the American Society of Heating, Refrigerating and Air-Conditioning Engineers 9-point Analog Sensation Scale after each swill and at baseline (preconditioning block). Acceptability was measured after baseline swill and S3 using a 5-question Likert scale. Physical performance was measured throughout training using global positioning system metrics. RESULTS MR attenuated TS from baseline to S1 (P = .003, SD = 1.01) and S2 (P = .002, SD = 1.09) in Forwards only, compared with PLA. Acceptability was higher only for Forwards in MR versus PLA at baseline (P = .003, SD = 1.3) and S3 (P = .004, SD = 0.75). MR had no effect on physical performance metrics (P > .05). CONCLUSION MR attenuated the rise in TS with higher acceptability at S1 and S3 (in Forwards only) with no effect on selected physical performance metrics. Longer-duration exercise (eg, a match) in hot-humid conditions eliciting markedly increased body temperatures could theoretically allow favorable changes in TS to enhance performance-these postulations warrant experimental investigation.
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Affiliation(s)
- Marcia L Jerram
- Department of Human Nutrition, University of Otago, Dunedin,New Zealand
| | - Dane Baker
- Department of Human Nutrition, University of Otago, Dunedin,New Zealand
| | | | - Phil Healey
- Blues Super Rugby Franchise, Auckland,New Zealand
| | - Lee Taylor
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine (NCSEM), Loughborough University, Loughborough,United Kingdom
- Human Performance Research Centre, University of Technology Sydney (UTS), Sydney, NSW,Australia
- Sport & Exercise Discipline Group, Faculty of Health, University of Technology Sydney (UTS), Sydney, NSW,Australia
| | - Katherine Black
- Department of Human Nutrition, University of Otago, Dunedin,New Zealand
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Vogel RM, Varone N, Clark C, Ramirez K, Ross MLR, Swann C, Stevens CJ. A Menthol-Enhanced "Cooling" Energy Gel Does Not Influence Laboratory Time Trial Performance in Trained Runners. Nutrients 2023; 15:3379. [PMID: 37571316 PMCID: PMC10420894 DOI: 10.3390/nu15153379] [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: 06/15/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
l-menthol (menthol) is an organic compound derived from peppermint which imparts a refreshing mint flavor and aroma to oral hygiene products, chewing gum, and topical analgesics. Menthol has been identified as a non-thermal sensory cooling strategy for athletes when ingested or mouth-rinsed during exercise in hot environments. Therefore, sports nutrition products delivering a controlled concentration of menthol could be beneficial for athletes exercising in the heat. We sought to test the performance and perceptual outcomes of a novel menthol energy gel during treadmill running in the heat (33 °C, 49% RH). Fourteen trained runners (mean ± SD; age: 31 ± 6 years, VO2max: 56.5 ± 10.1 mL·kg-1·min-1, BMI: 23.2 ± 2.4 kg/m2; six female) participated in a randomized, crossover, double-blind, and placebo-controlled study. A menthol-enhanced energy gel (0.5% concentration; MEN) or flavor-matched placebo (PLA) was ingested 5 min before and again at 20 and 40 min of a 40 min treadmill exercise preload at 60% VO2max, followed by a 20 min self-paced time trial. The total distance, vertical distance, perceptual measures (thermal comfort, thermal sensation, rating of perceived exertion, and affect), and cognitive performance via computerized neurocognitive assessment were measured. No difference between 20 min self-paced time trial total distance (MEN: 4.22 ± 0.54 km, PLA: 4.22 ± 0.55 km, p = 0.867), vertical distance (MEN: 49.2 ± 24.6 m, PLA: 44.4 ± 11.4 m, p = 0.516), or any perceptual measures was observed (all p > 0.05). Cognitive performance was not different between the trials (all p > 0.05). These results suggest that a menthol energy gel is not superior to a non-menthol gel in terms of performance or perception during treadmill running in the heat. More research is needed to confirm whether these findings translate to ecologically valid settings, including outdoor exercise in ambient heat and during competition.
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Affiliation(s)
- Roxanne M. Vogel
- Physical Activity, Sport and Exercise Research (PASER) Theme, Faculty of Health, Southern Cross University, Coffs Harbour, NSW 2450, Australia
- GU Energy Labs, Berkeley, CA 94710, USA
| | - Nicole Varone
- School of Health Promotion & Kinesiology, Texas Woman’s University, Denton, TX 76201, USA (K.R.)
| | - Cayla Clark
- School of Health Promotion & Kinesiology, Texas Woman’s University, Denton, TX 76201, USA (K.R.)
| | - Kyndall Ramirez
- School of Health Promotion & Kinesiology, Texas Woman’s University, Denton, TX 76201, USA (K.R.)
| | | | - Christian Swann
- Physical Activity, Sport and Exercise Research (PASER) Theme, Faculty of Health, Southern Cross University, Coffs Harbour, NSW 2450, Australia
| | - Christopher J. Stevens
- Physical Activity, Sport and Exercise Research (PASER) Theme, Faculty of Health, Southern Cross University, Coffs Harbour, NSW 2450, Australia
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Vogel RM, Ross MLR, Swann C, Rothwell JE, Stevens CJ. Athlete perceptions of flavored, menthol-enhanced energy gels ingested prior to endurance exercise in the heat. J Int Soc Sports Nutr 2022; 19:580-592. [DOI: 10.1080/15502783.2022.2117995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Roxanne M Vogel
- Southern Cross University, Discipline of Sport and Exercise Science, Coffs Harbour, Australia
- GU Energy Labs, Berkeley, CA, USA
| | - Megan LR Ross
- Australian Catholic University, Melbourne, Australia
| | - Christian Swann
- Southern Cross University, Discipline of Sport and Exercise Science, Coffs Harbour, Australia
| | - Jessica E Rothwell
- Athletics Australia, Melbourne, Australia
- Victorian Institute of Sport, Australia
| | - Christopher J Stevens
- Southern Cross University, Discipline of Sport and Exercise Science, Coffs Harbour, Australia
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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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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: 8] [Impact Index Per Article: 4.0] [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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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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Perceptual and Physiological Responses to Carbohydrate and Menthol Mouth-Swilling Solutions: A Repeated Measures Cross-Over Preliminary Trial. BEVERAGES 2021. [DOI: 10.3390/beverages7010009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Carbohydrate and menthol mouth-swilling have been used to enhance exercise performance in the heat. However, these strategies differ in mechanism and subjective experience. Participants (n = 12) sat for 60 min in hot conditions (35 °C; 15 ± 2%) following a 15 min control period, during which the participants undertook three 15 min testing blocks. A randomised swill (carbohydrate; menthol; water) was administered per testing block (one swill every three minutes within each block). Heart rate, tympanic temperature, thermal comfort, thermal sensation and thirst were recorded every three minutes. Data were analysed by ANOVA, with carbohydrate intake controlled for via ANCOVA. Small elevations in heart rate were observed after carbohydrate (ES: 0.22 ± 90% CI: −0.09–0.52) and water swilling (0.26; −0.04–0.54). Menthol showed small improvements in thermal comfort relative to carbohydrate (−0.33; −0.63–0.03) and water (−0.40; from −0.70 to −0.10), and induced moderate reductions in thermal sensation (−0.71; from −1.01 to −0.40 and −0.66; from −0.97 to −0.35, respectively). Menthol reduced thirst by a small to moderate extent. These effects persisted when controlling for dietary carbohydrate intake. Carbohydrate and water may elevate heart rate, whereas menthol elicits small improvements in thermal comfort, moderately improves thermal sensation and may mitigate thirst; these effects persist when dietary carbohydrate intake is controlled for.
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