Medicine and Science in Sports and Exercise最新文献

{"title":"Consuming Whey Protein with Added Essential Amino Acids, Not Carbohydrate, Maintains Postexercise Anabolism While Underfed.","authors":"Jess A Gwin, David D Church, Jillian T Allen, Marques A Wilson, Christopher T Carrigan, Nancy E Murphy, Alyssa N Varanoske, Lee M Margolis, Robert R Wolfe, Arny A Ferrando, Stefan M Pasiakos","doi":"10.1249/MSS.0000000000003541","DOIUrl":"10.1249/MSS.0000000000003541","url":null,"abstract":"<p><strong>Purpose: </strong>Energy deficiency decreases muscle protein synthesis (MPS), possibly due to greater whole-body essential amino acid (EAA) requirements and reliance on energy stores. Whether energy deficit-induced anabolic resistance is overcome with non-nitrogenous supplemental energy or if increased energy as EAA is needed is unclear. We tested the effects of energy as EAA or carbohydrate, combined with an EAA-enriched whey protein, on postexercise MPS (%·h -1 ) and whole-body protein turnover (g protein·240 min -1 ).</p><p><strong>Methods: </strong>Seventeen adults (mean ± SD; age: 26 ± 6 yr, body mass index: 25 ± 3 kg·m -2 ) completed a randomized, parallel study including two 5-d energy conditions (BAL; energy balance; daily energy requirements (DEF), -30% ± 3% energy requirements) separated by ≥7 d. Volunteers consumed EAA-enriched whey with added EAA (+EAA; 304 kcal, 56 g protein, 48 g EAA, 17 g carbohydrate, 2 g fat; n = 8) or added carbohydrate (+CHO; 311 kcal, 34 g protein, 24 g EAA, 40 g carbohydrate, 2 g fat; n = 9) following exercise. MPS and whole-body protein synthesis (PS), breakdown (PB), and net balance (NET; PS-PB) were estimated postexercise with isotope kinetics.</p><p><strong>Results: </strong>MPS rates were greater in +EAA (0.083 ± 0.02) than +CHO (0.059 ± 0.01; P = 0.015) during daily energy requirements, but similar during BAL ( P = 0.45) and across energy conditions within treatments ( P = 0.056). PS rates were greater for +EAA (BAL, 117.9 ± 16.5; daily energy requirements, 110.3 ± 14.8) than +CHO (BAL, 81.6 ± 8.0; daily energy requirements, 83.8 ± 5.9 g protein·240 min -1 ; both P < 0.001) and greater during BAL than daily energy requirements in +EAA ( P = 0.045). PB rates were less in +EAA (8.0 ± 16.5) than +CHO (37.8 ± 7.6 g protein·240 min -1 ; P < 0.001), and NET was greater in +EAA (106.1 ± 6.3) than +CHO (44.8 ± 8.5 g protein·240 min -1 ; P < 0.001).</p><p><strong>Conclusions: </strong>These data suggest that supplementing EAA-enriched whey protein with more energy as EAA, not carbohydrate, maintains postexercise MPS during energy deficit at rates comparable to those observed during energy balance.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"70-80"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex Differences in Ambulatory Biomechanics: A Meta-Analysis Providing a Mechanistic Insight into Knee Osteoarthritis.","authors":"Momoko Yamagata, Tetsuya Kimura, Alison H Chang, Hirotaka Iijima","doi":"10.1249/MSS.0000000000003549","DOIUrl":"10.1249/MSS.0000000000003549","url":null,"abstract":"<p><strong>Purpose: </strong>Females typically present with a higher prevalence of knee osteoarthritis (KOA), and such a higher prevalence may be due to unique knee biomechanics during walking. However, the sex-dependent ambulatory mechanics has been yet to be clarified. To address this critical knowledge gap, this study implemented a series of computational approaches 1) to identify sex-related knee joint biomechanics during ambulation in persons with KOA and 2) to compare these biomechanical measures between individuals with versus without KOA, stratified by sex.</p><p><strong>Methods: </strong>We searched five electronic databases for studies reporting sex-specific knee biomechanics in persons with and/or without KOA. Summary estimates were computed using random-effects meta-analysis and stratified by sex.</p><p><strong>Results: </strong>The systematic review identified 18 studies (308 males and 383 females with KOA; 740 males and 995 females without KOA). A series of meta-analyses identified female-specific knee biomechanics in a disease-dependent manner. Females with KOA had lower first peak knee adduction moment and peak knee adduction compared with male counterparts. On the other hand, healthy females had lower peak knee flexion moment than male counterparts. Effect estimate in each meta-analysis displayed poor quality of evidence according to the GRADE approach.</p><p><strong>Conclusions: </strong>The current study is the first to consider sex as a biological variable into ambulatory mechanics in the development of KOA. We discovered that sex-dependent alterations in knee biomechanics is a function of the presence of KOA, indicating that KOA disease may be a driver of the sex-dependent biomechanical alterations or vice versa. Although no strong conclusion can be drawn because of the low quality of evidence, these findings provide new insight into the sex differences in ambulatory knee biomechanics and progression of KOA.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"144-153"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Significance of Body Surface Area to Mass Ratio for Thermal Responses to a Standardized Exercise-Heat Stress Test.","authors":"Inbal Akavian, Yoram Epstein, Alexandra Rabotin, Shiraz Peretz, Nisha Charkoudian, Itay Ketko","doi":"10.1249/MSS.0000000000003545","DOIUrl":"10.1249/MSS.0000000000003545","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the significance of body surface area-to-mass ratio (BSA/mass) on the heat-tolerance test (HTT) results. We hypothesized that individuals defined as heat tolerant (HT) would have on average higher BSA/mass compared with heat intolerant (HI) individuals.</p><p><strong>Methods: </strong>A retrospective reanalysis of the HTT results of 517 soldiers (age, 18-38 yr; M/F, 96%:4%), who were tested by the Israel Defense Forces HTT protocol. The criterion for heat tolerance in the current analysis was a rectal temperature (T re ) plateau during the second hour of the test. A logistic regression analysis to evaluate the predictive power of BSA/mass for heat intolerance was performed; the spline model was applied to show the odds for heat intolerance across BSA/mass.</p><p><strong>Results: </strong>In men BSA/mass of HI individuals was lower than HT individuals (248 ± 19 vs 262 ± 18 cm 2 ·kg -1 , P < 0.01, d = 0.76). In women a similar trend was noted but with no statistical significance between HT and HI groups. The odd ratio for heat intolerance for every unit increase in BSA/mass was 0.97 (95% confidence interval, 0.95-0.99). The spline model plateaued above BSA/mass of 270 cm 2 ·kg -1 .</p><p><strong>Conclusions: </strong>The results imply that body-core temperature responses to a standard exercise-heat stress (fixed external work rate and climatic conditions) are influenced by BSA/mass. More specifically, lack of a steady state in T re (indicating heat intolerance) was more likely to occur with every unit decrease in BSA/mass. These findings contribute to a better understanding of the role of body anthropometry in the response to a standard exercise-heat task that might have an implication on clinical decision making about return to duty/play of soldiers, athletes, and others who deemed to be identified as HI.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"88-93"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142109226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Load-Velocity Slope Is an Indicator of the Active Drag in All Competitive Swimming Strokes.","authors":"Tomohiro Gonjo, Maria Vitazka, Ingeborg Ljødal, Bjørn Harald Olstad","doi":"10.1249/MSS.0000000000003551","DOIUrl":"10.1249/MSS.0000000000003551","url":null,"abstract":"<p><strong>Introduction: </strong>Active drag in swimming is a critical variable that affects swimmers' performance, as well as the physiological load, but it is challenging for practitioners to assess this variable. This study aimed to assess if the load-velocity profiling method can be used as an indicator of active drag.</p><p><strong>Methods: </strong>A total of 419 swimmers performed three semitethered swimming trials in their speciality among the four competitive strokes with different external loads. Linear regression between external load and swimming velocity, as well as the external load relative to the body mass and swimming velocity, were established. The active drag and drag coefficient of each swimmer were calculated using a velocity perturbation method.</p><p><strong>Results: </strong>There were significant correlations of the active drag with the absolute slope ( correlation coefficient ≥ 0.696, P < 0.001) and relative slope ( correlation coefficient ≥ 0.538, P < 0.001) in all four strokes and both sexes. A multiple regression analysis exhibited that the primary determinant of these relationships was the drag coefficient (semipartial correlation ≥0.422, P < 0.001). The effects of the height and body mass index (BMI) on the relationship between the drag and the absolute slope were small (0.195 ≤ semipartial correlation ≤0.249, P < 0.001), which became either nonsignificant (height: P ≥ 0.282) or trivial (BMI: -0.099 ≤ semipartial correlation ≤ -0.081, P ≤ 0.011) when focusing on the relative slope.</p><p><strong>Conclusions: </strong>These results indicate that the absolute load-velocity slope is a strong indicator of the active drag, and the relative slope is useful when indirectly assessing the drag coefficient.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"115-122"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muscle Mitochondrial Capacity Is Impaired Immediately Following Maximal Exercise.","authors":"Callie G Dickinson, Kristin M Mendez, Makayla D Holyfield, Nicholas T Batchelor, Kevin K McCully","doi":"10.1249/MSS.0000000000003533","DOIUrl":"10.1249/MSS.0000000000003533","url":null,"abstract":"<p><strong>Purpose: </strong>This study measured the time course mV̇O 2 max following both maximal and submaximal exercise.</p><p><strong>Methods: </strong>Healthy male and female participants were tested ( n = 12 maximal and n = 8 submaximal exercise). A NIRS device was placed on the left medial gastrocnemius. Participants performed either 1 min of maximal, rapid (~2 Hz), or submaximal (~0.37 Hz) plantar flexion exercise on a custom pneumatic ergometer. mV̇O 2 max was measured before and immediately after exercise. mV̇O 2 max measurements consisted of four incomplete recovery curves of muscle metabolism taken after 30 s of electrical muscle stimulation except in the first post-exercise to be consistent with the use of pre-exercise trial. The four recovery curves were collected 50-, 156-, 260-, and 366-s postexercise, each producing an mV̇O 2 max rate constant.</p><p><strong>Results: </strong>After maximal exercise, muscle acceleration decreased to 52 ± 18% ( P = 0.001) of prevalues. mV̇O 2 max was reduced from the pre-exercise mean at the first post-trial (2.16 ± 0.44 to 1.21 ± 0.52 min -1 , P < 0.001). The fourth trial showed recovery from the first (2.2 ± 0.46 min -1 vs 1.21 ± 0.52 min -1 , P < 0.001) and was not significantly different from pre-exercise values (2.2 ± 0.46 vs 2.16 ± 0.44 min -1 , P = 0.41). No change in acceleration or mV̇O 2 max was seen after submaximal exercise ( P > 0.05).</p><p><strong>Conclusions: </strong>The 56.7% reduction in mV̇O 2 max supports the hypothesis that in young, healthy individuals, a minute of maximal exercise transiently impairs mV̇O 2 max, which then recovers within 6 min. The NIRS method shows promise in tracking time course changes in mV̇O 2 max and warrants further investigation of the transient effects of exercise on mV̇O 2 max.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"173-180"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining Individualized Foot Progression Angle for Reduction of Knee Medial Compartment Loading during Stepping.","authors":"Raziyeh Baghi, Wei Yin, Ahmed Ramadan, Subham Badhyal, Giovanni Oppizzi, Dali Xu, Peter Bowman, Frank Henn, Li-Qun Zhang","doi":"10.1249/MSS.0000000000003531","DOIUrl":"10.1249/MSS.0000000000003531","url":null,"abstract":"<p><strong>Purpose: </strong>Modifying foot progression angle (FPA), the angle between the line from the heel to the second metatarsal head and the line of progression, can reduce peak knee adduction moment (pKAM). However, determining the optimal FPA that minimizes pKAM without inducing unnatural walking patterns can be challenging. This study investigated the FPA-pKAM relationship using a robotic stepping trainer to assess the feasibility of determining the optimal FPA based on this relationship. In addition, it examined knee moments during stepping with three different FPAs, as stepping is a recommended exercise for knee osteoarthritis rehabilitation.</p><p><strong>Methods: </strong>Twenty-six asymptomatic individuals stepped on a robotic stepping trainer, which measured six-axis footplate-reaction forces/torques and three-dimensional ankle kinematics to determine external knee moments. The robot rotated the footplates slowly (~0.5 deg·s -1 ) between 10°-toe-out and 10°-toe-in while participants stepped continuously, unaware of the footplate rotations. The slope of pKAM-FPA relationship during continuous stepping was determined. Peak three-dimensional knee moments were compared between the 10°-toe-in, 0°-FPA, and 10°-toe-out FPAs with repeated-measures ANOVA. Multiple linear regression determined the covariates that predicted pKAM during stepping.</p><p><strong>Results: </strong>Eighteen participants had lower pKAM and KAM impulse with 10°-toe-in than 10°-toe-out ( P < 0.001) and 0°-FPA ( P < 0.001 and P = 0.008, respectively; called toe-in responders). Conversely, eight participants reduced pKAM and KAM impulse with 10°-toe-out compared with 0°-FPA ( P < 0.001, P = 0.017) and 10°-toe-in ( P = 0.026, P = 0.004; called toe-out responders). A linear pKAM-FPA relationship was determined for each individual, and its slope (the pKAM rate with FPA) was positive for toe-in responders ( P < 0.01) and negative for toe-out responders ( P = 0.02). Regression analysis revealed that smaller pKAM with toe-in, in toe-in responders, was explained by increased tibia medial tilt, tibia internal rotation, footplate-reaction lateral force, footplate-reaction anterior force, and decreased footplate-reaction internal rotation torque.</p><p><strong>Conclusions: </strong>Individuals may exhibit different responses to FPA modification during stepping. The slope and intercept of the linear pKAM-FPA relationship can be determined for individual subjects. This allows for a targeted pKAM reduction through guided FPA positioning and potentially offers subject-specific precision knee osteoarthritis rehabilitation.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"33-43"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142073144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic Heat Production Modulates the Cardiovascular Drift-V̇O 2max Relationship Independent of Aerobic Fitness in Women.","authors":"Tori Stone, Sarah G Burnash, Ryan L Earley, Annie M Mulholland, Hillary A Yoder, Hayley V Macdonald, Mark T Richardson, Jonathan E Wingo","doi":"10.1249/MSS.0000000000003543","DOIUrl":"10.1249/MSS.0000000000003543","url":null,"abstract":"<p><strong>Introduction/purpose: </strong>The purpose of this study was to test the hypothesis that cardiovascular (CV) drift and associated decrements in maximal oxygen uptake (V̇O 2max ) are greater in high-fit compared with low-fit women during exercise at the same %V̇O 2max , but comparable at the same rate of metabolic heat production.</p><p><strong>Methods: </strong>Six high-fit (HI) and six low-fit (LO) women cycled in 35°C for 15 or 45 min at the same relative intensity (60% V̇O 2max ; 15REL and 45REL) or fixed rate of heat production (500 W; 15FX and 45FX), immediately followed by a graded exercise test to measure V̇O 2max . The separate 15- and 45-min trials permitted measurements of V̇O 2max over the same time interval as CV drift.</p><p><strong>Results: </strong>During 45REL, higher heat production in HI (496 ± 51 vs 364 ± 44 W in LO) resulted in greater end-exercise core temperature (38.7°C ± 0.4°C vs 38.2°C ± 0.1°C, P = 0.03), greater increases in HR (15 bpm (10%) vs 10 bpm (6%), P = 0.03) and decreases in stroke volume (11 mL per beat (16%) vs 5 mL per beat (8%), P = 0.001), and larger reductions in V̇O 2max (16% vs 5%, P = 0.04) compared with LO. During 45FX, temperature responses, CV drift, and decreased V̇O 2max were not different between groups (all P > 0.05), despite differences in %V̇O 2max (60% vs 75% for HI and LO, respectively).</p><p><strong>Conclusions: </strong>We conclude metabolic heat production modulates the CV drift-V̇O 2max relationship, independent of fitness level. These results support previous findings showing the magnitude of CV drift is proportional to reductions in V̇O 2max .</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"181-191"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat Suit Training Preserves the Increased Hemoglobin Mass after Altitude Camp in Elite Cyclists.","authors":"Bent R Rønnestad, Ingvill Odden, Tomas Urianstad, Joar Hansen, Knut S Mølmen, Daniele A Cardinale","doi":"10.1249/MSS.0000000000003542","DOIUrl":"10.1249/MSS.0000000000003542","url":null,"abstract":"<p><strong>Purpose: </strong>Altitude training is a common strategy used with the intent to increase hemoglobin mass (Hb mass ) in athletes. However, if the Hb mass is increased during altitude camps, it seems to decline rapidly upon returning to sea level. This study aimed to examine the efficacy of three weekly heat training sessions over a 3.5-wk period after a 3-wk altitude camp on the maintenance of Hb mass in elite cyclists.</p><p><strong>Methods: </strong>Eighteen male cyclists (maximal oxygen consumption: 76 ± 5 mL·min -1 ·kg -1 ) underwent a 3-wk altitude training camp at ~2100 m above sea level. After the camp, participants were divided into one group performing three weekly heat sessions that were subtracted from their usual training (HEAT) while the other continuing usual training (CON). Training characteristics were recorded during the intervention, whereas hematological measurements were recorded before the camp as well as 2 d and 3.5 wk after the altitude camp.</p><p><strong>Results: </strong>The 3-wk altitude camp led to an overall increase in total Hb mass of 4.1%. Afterward, HEAT maintained Hb mass (0.2%, P = 0.738), whereas CON group experienced a significant reduction (-3.3%, P < 0.001) (ΔHEAT vs ΔCON, P < 0.001). Moreover, HEAT increased plasma volume (PV) by 11.6% ( P = 0.007) and blood volume (BV) by 5.8% ( P = 0.007), whereas CON only showed an increase in PV (5.5%, P = 0.041). Exercise intensity and training load were not different between groups during the maintenance period.</p><p><strong>Conclusions: </strong>This study suggests that incorporating three weekly heat training sessions into the usual training routine preserves a moderately increased Hb mass in elite cyclists after an altitude camp.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"81-87"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core Temperature Response to Cold Water Immersion in Heat Stroke Patients Is Nonlinear and Unrelated to Sex or Body Size.","authors":"Coen C W G Bongers, Mandy A G Peggen, Geoffrey M Minett, Nick Kruijt, Bram Goris, Maria T E Hopman","doi":"10.1249/MSS.0000000000003547","DOIUrl":"10.1249/MSS.0000000000003547","url":null,"abstract":"<p><strong>Purpose: </strong>Cold water immersion (CWI) is the most effective treatment for exertional heat stroke (EHS). However, knowledge on core temperature response during CWI treatment and the relation with patient characteristics (i.e., sex, anthropometrics) is limited. Therefore, the current study aimed to examine the core temperature response (in °C) during CWI treatment of recreational athletes participating in large running events and investigate the impact of sex and anthropometric characteristics on the cooling rate (in °C·min -1 ).</p><p><strong>Methods: </strong>This observational study includes 57 athletes ( n = 22 females; 39%) who suffered from EHS during an exercise event in the Netherlands. After admission to the medical facilities, a rectal temperature ( Trec ) probe was inserted and all clothing was removed before immersion in an ice bath (6.4 ± 1.6°C). Rectal temperature was continuously measured throughout treatment, and treatment was continued until Trec ≤ 38.9°C or based on the decision of the emergency physician.</p><p><strong>Results: </strong>Initial Trec did not differ between males (41.3 ± 0.9°C) and females (41.2 ± 0.8°C, P = 0.83). A nonlinear response to CWI was observed, with the decrease in Trec beginning after 6 min of CWI. The decrease in Trec did not differ between both sexes (p time*sex = 0.96). The cooling rate did not differ between males (0.21 ± 0.15°C·min -1 ) and females (0.19 ± 0.08°C·min -1 , P = 0.55), and was not related to body mass, body surface area and body surface area to mass ratio (all P values >0.05).</p><p><strong>Conclusions: </strong>We demonstrated that the cooling rate during CWI did not differ between men and women suffering from EHS, and that the Trec response to CWI is nonlinear and not dependent on anthropometric characteristics. This suggests that no sex differentiation is needed in the EHS treatment guidelines and confirms the necessity to continuously monitor Trec during treatment.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"192-200"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142009065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Ketone Monoester Supplementation Does Not Change Exercise Efficiency during Incremental Cycling in Trained Individuals.","authors":"Jack Bone, Sydney Baumgarten, Devin G McCarthy, William Bostad, Douglas L Richards, Martin J Gibala","doi":"10.1249/MSS.0000000000003532","DOIUrl":"10.1249/MSS.0000000000003532","url":null,"abstract":"<p><strong>Methods: </strong>Twenty-eight adults (16 males and 12 females) aged 30 ± 10 yr (peak oxygen uptake (V̇O 2peak ): 59 ± 11 mL·kg -1 ·min -1 ) completed three experimental trials in a randomized, crossover, and double-blinded manner. Participants ingested either 0.3 (KE-LO) or 0.6 (KE-HI) g·kg -1 body mass of KE or a flavor-matched placebo (PLAC) ~30 min before exercise. Exercise involved a 3-min warm-up, three 5-min stages at fixed incremental workloads corresponding to 75%, 100%, and 125% of individual ventilatory threshold, followed by a ramp protocol to volitional exhaustion to determine peak power output (PPO).</p><p><strong>Results: </strong>Venous blood [ß-hydroxybutyrate], the major circulating ketone body, was higher after KE ingestion compared with PLAC (KE-HI: 3.0 ± 1.1 ≥ KE-LO: 2.3 ± 0.6 ≥ PLAC: 0.2 ± 0.1 mM; all P ≤ 0.001. There were no differences between conditions in the primary outcome exercise economy, nor gross efficiency or delta efficiency, when analyzed over the entire submaximal exercise period or by stage. Heart rate and ventilation were higher in KE-HI and KE-LO compared with PLAC when assessed over the entire submaximal exercise period and by stage (all P ≤ 0.05). PPO after the ramp was lower in KE-HI compared with both KE-LO and PLAC (329 ± 60 vs 339 ± 62 and 341 ± 61 W, respectively; both P < 0.05) despite no difference in V̇O 2peak .</p><p><strong>Conclusions: </strong>KE ingestion did not change indices of exercise efficiency but increased markers of cardiorespiratory stress during submaximal incremental cycling and reduced PPO.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"163-172"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142073229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}