Pub Date : 2023-07-01DOI: 10.1123/ijsnem.2023-0015
Sarah R Jackman, Gareth A Wallis, Jinglei Yu, Andrew Philp, Keith Baar, Kevin D Tipton, Oliver C Witard
Branched-chain amino acids (BCAA) and carbohydrate (CHO) are commonly recommended postexercise supplements. However, no study has examined the interaction of CHO and BCAA ingestion on myofibrillar protein synthesis (MyoPS) rates following exercise. We aimed to determine the response of MyoPS to the co-ingestion of BCAA and CHO following an acute bout of resistance exercise. Ten resistance-trained young men completed two trials in counterbalanced order, ingesting isocaloric drinks containing either 30.6-g CHO plus 5.6-g BCAA (B + C) or 34.7-g CHO alone following a bout of unilateral, leg resistance exercise. MyoPS was measured postexercise with a primed, constant infusion of L-[ring13C6] phenylalanine and collection of muscle biopsies pre- and 4 hr postdrink ingestion. Blood samples were collected at time points before and after drink ingestion. Serum insulin concentrations increased to a similar extent in both trials (p > .05), peaking at 30 min postdrink ingestion. Plasma leucine (514 ± 34 nmol/L), isoleucine (282 ± 23 nmol/L), and valine (687 ± 33 nmol/L) concentrations peaked at 0.5 hr postdrink in B + C and remained elevated for 3 hr during exercise recovery. MyoPS was ∼15% greater (95% confidence interval [-0.002, 0.028], p = .039, Cohen's d = 0.63) in B + C (0.128%/hr ± 0.011%/hr) than CHO alone (0.115%/hr ± 0.011%/hr) over the 4 hr postexercise period. Co-ingestion of BCAA and CHO augments the acute response of MyoPS to resistance exercise in trained young males.
支链氨基酸(BCAA)和碳水化合物(CHO)是通常推荐的运动后补充。然而,没有研究检查CHO和BCAA摄入对运动后肌原纤维蛋白合成(MyoPS)率的相互作用。我们的目的是确定MyoPS对急性抗阻运动后同时摄入BCAA和CHO的反应。10名接受过阻力训练的年轻男性按平衡顺序完成了两项试验,他们分别摄入含有30.6 g CHO加5.6 g BCAA (B + C)或34.7 g CHO的等热量饮料,然后进行一轮单侧腿部阻力运动。运动后用L-[ring13C6]苯丙氨酸持续灌注,并在饮酒前和饮酒后4小时收集肌肉活检,测量MyoPS。在饮酒前后各时间点采集血样。在两项试验中,血清胰岛素浓度升高的幅度相似(p > 0.05),在饮酒后30分钟达到峰值。B + C组血浆亮氨酸(514±34 nmol/L)、异亮氨酸(282±23 nmol/L)和缬氨酸(687±33 nmol/L)浓度在饮酒后0.5小时达到峰值,并在运动恢复期间持续升高3小时。运动后4小时,B + C组MyoPS (0.128%/hr±0.011%/hr)比CHO组MyoPS (0.115%/hr±0.011%/hr)高约15%(95%可信区间[-0.002,0.028],p = 0.039, Cohen’s d = 0.63)。在受过训练的年轻男性中,BCAA和CHO的共同摄入增加了MyoPS对抗阻运动的急性反应。
{"title":"Co-Ingestion of Branched-Chain Amino Acids and Carbohydrate Stimulates Myofibrillar Protein Synthesis Following Resistance Exercise in Trained Young Men.","authors":"Sarah R Jackman, Gareth A Wallis, Jinglei Yu, Andrew Philp, Keith Baar, Kevin D Tipton, Oliver C Witard","doi":"10.1123/ijsnem.2023-0015","DOIUrl":"https://doi.org/10.1123/ijsnem.2023-0015","url":null,"abstract":"<p><p>Branched-chain amino acids (BCAA) and carbohydrate (CHO) are commonly recommended postexercise supplements. However, no study has examined the interaction of CHO and BCAA ingestion on myofibrillar protein synthesis (MyoPS) rates following exercise. We aimed to determine the response of MyoPS to the co-ingestion of BCAA and CHO following an acute bout of resistance exercise. Ten resistance-trained young men completed two trials in counterbalanced order, ingesting isocaloric drinks containing either 30.6-g CHO plus 5.6-g BCAA (B + C) or 34.7-g CHO alone following a bout of unilateral, leg resistance exercise. MyoPS was measured postexercise with a primed, constant infusion of L-[ring13C6] phenylalanine and collection of muscle biopsies pre- and 4 hr postdrink ingestion. Blood samples were collected at time points before and after drink ingestion. Serum insulin concentrations increased to a similar extent in both trials (p > .05), peaking at 30 min postdrink ingestion. Plasma leucine (514 ± 34 nmol/L), isoleucine (282 ± 23 nmol/L), and valine (687 ± 33 nmol/L) concentrations peaked at 0.5 hr postdrink in B + C and remained elevated for 3 hr during exercise recovery. MyoPS was ∼15% greater (95% confidence interval [-0.002, 0.028], p = .039, Cohen's d = 0.63) in B + C (0.128%/hr ± 0.011%/hr) than CHO alone (0.115%/hr ± 0.011%/hr) over the 4 hr postexercise period. Co-ingestion of BCAA and CHO augments the acute response of MyoPS to resistance exercise in trained young males.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 4","pages":"189-197"},"PeriodicalIF":2.5,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9679293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-24Print Date: 2023-09-01DOI: 10.1123/ijsnem.2022-0203
Colleen X Muñoz, Michael F Bergeron
First morning urine (FMU) assessment would be a practical and convenient solution for clinically acceptable detection of underhydration prior to competition/training, and for the general public. Thus, we thus sought to determine the diagnostic accuracy of FMU as a valid indicator of recent (previous 24 hr, 5 days average) hydration practices. For 5 consecutive days and one final morning, 67 healthy women (n = 38) and men (n = 29; age: 20 [1] years, body mass index: 25.9 [5.5]) completed 24-hr diet logs for total water intake (from beverages and foods, absolute and relative to body mass), 24-hr urine and FMU collection (last morning only) for osmolality (Osm), specific gravity (SG), and color (Col), and morning blood sampling for plasma osmolality and copeptin. Correlations determined significance and relationship strength among FMU and all other variables. Area under the receiver operating characteristic curves, sensitivity, specificity, and positive likelihood ratios were employed using previously reported values to indicate underhydration (total water intake < 30 ml/kg, osmolality > 500, and >800 mOsm/kg, specific gravity > 1.017, and copeptin > 6.93 pmol/L). FMU_Osm and FMU_SG were significantly correlated (p < .05) to all variables except the previous 5-day plasma osmolality. FMU_Col was only significantly correlated with other color time intervals and total water intake per gram. FMU_Osm held greatest utility (area under the receiver operating characteristic curve, sensitivity, and specificity >80%) overall, with the best outcome being FMU_Osm indicating a previous 24-hr osmolality threshold of 500 mOsm/kg (FMU_Osm criterion >710 mOsm/kg and positive likelihood ratio = 5.9). With less effort and cost restriction, FMU is a viable metric to assess underhydration.
{"title":"Characterizing Hydration Practices in Healthy Young Recreationally Active Adults-Is There Utility in First Morning Urine Sampling?","authors":"Colleen X Muñoz, Michael F Bergeron","doi":"10.1123/ijsnem.2022-0203","DOIUrl":"10.1123/ijsnem.2022-0203","url":null,"abstract":"<p><p>First morning urine (FMU) assessment would be a practical and convenient solution for clinically acceptable detection of underhydration prior to competition/training, and for the general public. Thus, we thus sought to determine the diagnostic accuracy of FMU as a valid indicator of recent (previous 24 hr, 5 days average) hydration practices. For 5 consecutive days and one final morning, 67 healthy women (n = 38) and men (n = 29; age: 20 [1] years, body mass index: 25.9 [5.5]) completed 24-hr diet logs for total water intake (from beverages and foods, absolute and relative to body mass), 24-hr urine and FMU collection (last morning only) for osmolality (Osm), specific gravity (SG), and color (Col), and morning blood sampling for plasma osmolality and copeptin. Correlations determined significance and relationship strength among FMU and all other variables. Area under the receiver operating characteristic curves, sensitivity, specificity, and positive likelihood ratios were employed using previously reported values to indicate underhydration (total water intake < 30 ml/kg, osmolality > 500, and >800 mOsm/kg, specific gravity > 1.017, and copeptin > 6.93 pmol/L). FMU_Osm and FMU_SG were significantly correlated (p < .05) to all variables except the previous 5-day plasma osmolality. FMU_Col was only significantly correlated with other color time intervals and total water intake per gram. FMU_Osm held greatest utility (area under the receiver operating characteristic curve, sensitivity, and specificity >80%) overall, with the best outcome being FMU_Osm indicating a previous 24-hr osmolality threshold of 500 mOsm/kg (FMU_Osm criterion >710 mOsm/kg and positive likelihood ratio = 5.9). With less effort and cost restriction, FMU is a viable metric to assess underhydration.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 5","pages":"265-274"},"PeriodicalIF":2.5,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9974032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-09Print Date: 2023-07-01DOI: 10.1123/ijsnem.2022-0214
Megan A Kuikman, Alannah K A McKay, Ella S Smith, Kathryn E Ackerman, Rachel Harris, Kirsty J Elliott-Sale, Trent Stellingwerff, Louise M Burke
The aim of this audit was to assess the representation of female athletes, dietary control methods, and gold standard female methodology that underpins the current guidelines for chronic carbohydrate (CHO) intake strategies for athlete daily training diets. Using a standardized audit, 281 studies were identified that examined high versus moderate CHO, periodized CHO availability, and/or low CHO, high fat diets. There were 3,735 total participants across these studies with only ∼16% of participants being women. Few studies utilized a design that specifically considered females, with only 16 studies (∼6%) including a female-only cohort and six studies (∼2%) with a sex-based comparison in their statistical procedure, in comparison to the 217 studies (∼77%) including a male-only cohort. Most studies (∼72%) did not provide sufficient information to define the menstrual status of participants, and of the 18 studies that did, optimal methodology for control of ovarian hormones was only noted in one study. While ∼40% of male-only studies provided all food and beverages to participants, only ∼20% of studies with a female-specific design used this approach for dietary control. Most studies did not implement strategies to ensure compliance to dietary interventions and/or control energy intake during dietary interventions. The literature that has contributed to the current guidelines for daily CHO intake is lacking in research that is specific to, or adequately addresses, the female athlete. Redressing this imbalance is of high priority to ensure that the female athlete receives evidence-based recommendations that consider her specific needs.
{"title":"Female Athlete Representation and Dietary Control Methods Among Studies Assessing Chronic Carbohydrate Approaches to Support Training.","authors":"Megan A Kuikman, Alannah K A McKay, Ella S Smith, Kathryn E Ackerman, Rachel Harris, Kirsty J Elliott-Sale, Trent Stellingwerff, Louise M Burke","doi":"10.1123/ijsnem.2022-0214","DOIUrl":"10.1123/ijsnem.2022-0214","url":null,"abstract":"<p><p>The aim of this audit was to assess the representation of female athletes, dietary control methods, and gold standard female methodology that underpins the current guidelines for chronic carbohydrate (CHO) intake strategies for athlete daily training diets. Using a standardized audit, 281 studies were identified that examined high versus moderate CHO, periodized CHO availability, and/or low CHO, high fat diets. There were 3,735 total participants across these studies with only ∼16% of participants being women. Few studies utilized a design that specifically considered females, with only 16 studies (∼6%) including a female-only cohort and six studies (∼2%) with a sex-based comparison in their statistical procedure, in comparison to the 217 studies (∼77%) including a male-only cohort. Most studies (∼72%) did not provide sufficient information to define the menstrual status of participants, and of the 18 studies that did, optimal methodology for control of ovarian hormones was only noted in one study. While ∼40% of male-only studies provided all food and beverages to participants, only ∼20% of studies with a female-specific design used this approach for dietary control. Most studies did not implement strategies to ensure compliance to dietary interventions and/or control energy intake during dietary interventions. The literature that has contributed to the current guidelines for daily CHO intake is lacking in research that is specific to, or adequately addresses, the female athlete. Redressing this imbalance is of high priority to ensure that the female athlete receives evidence-based recommendations that consider her specific needs.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 4","pages":"198-208"},"PeriodicalIF":2.5,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10032035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2022-0175
Laura Alvarez-Jimenez, Alfonso Moreno-Cabañas, Felix Morales-Palomo, Juan F Ortega, Ricardo Mora-Rodriguez
Objective: To determine whether statin medication in individuals with obesity, dyslipidemia, and metabolic syndrome affects their capacity to mobilize and oxidize fat during exercise.
Methods: Twelve individuals with metabolic syndrome pedaled during 75 min at 54 ± 13% V˙O2max (5.7 ± 0.5 metabolic equivalents) while taking statins (STATs) or after 96-hr statin withdrawal (PLAC) in a randomized double-blind fashion.
Results: At rest, PLAC increased low-density lipoprotein cholesterol (i.e., STAT 2.55 ± 0.96 vs. PLAC 3.16 ± 0.76 mmol/L; p = .004) and total cholesterol blood levels (i.e., STAT 4.39 ± 1.16 vs. PLAC 4.98 ± 0.97 mmol/L; p = .008). At rest, fat oxidation (0.99 ± 0.34 vs. 0.76 ± 0.37 μmol·kg-1·min-1 for STAT vs. PLAC; p = .068) and the rates of plasma appearance of glucose and glycerol (i.e., Ra glucose-glycerol) were not affected by PLAC. After 70 min of exercise, fat oxidation was similar between trials (2.94 ± 1.56 vs. 3.06 ± 1.94 μmol·kg-1·min-1, STA vs. PLAC; p = .875). PLAC did not alter the rates of disappearance of glucose in plasma during exercise (i.e., 23.9 ± 6.9 vs. 24.5 ± 8.2 μmol·kg-1·min-1 for STAT vs. PLAC; p = .611) or the rate of plasma appearance of glycerol (i.e., 8.5 ± 1.9 vs. 7.9 ± 1.8 μmol·kg-1·min-1 for STAT vs. PLAC; p = .262).
Conclusions: In patients with obesity, dyslipidemia, and metabolic syndrome, statins do not compromise their ability to mobilize and oxidize fat at rest or during prolonged, moderately intense exercise (i.e., equivalent to brisk walking). In these patients, the combination of statins and exercise could help to better manage their dyslipidemia.
目的:确定肥胖、血脂异常和代谢综合征患者服用他汀类药物是否会影响他们在运动中动员和氧化脂肪的能力。方法:12例代谢综合征患者在服用他汀类药物(STATs)或停药96小时(placc)后,在54±13% V˙O2max(5.7±0.5代谢当量)下骑行75分钟,采用随机双盲方法。结果:静息时,PLAC使低密度脂蛋白胆固醇升高(即STAT为2.55±0.96,PLAC为3.16±0.76 mmol/L;p = 0.004)和总胆固醇血水平(即STAT 4.39±1.16 vs plac4.98±0.97 mmol/L;P = .008)。静止状态下,STAT和placc的脂肪氧化(0.99±0.34 vs 0.76±0.37 μmol·kg-1·min-1);p = 0.068),血浆葡萄糖和甘油(即Ra葡萄糖-甘油)的出现率不受placc的影响。运动70 min后,两组之间的脂肪氧化相似(STA vs. PLAC, 2.94±1.56 vs. 3.06±1.94 μmol·kg-1·min-1;P = .875)。PLAC没有改变运动期间血浆中葡萄糖的消失率(即STAT和PLAC分别为23.9±6.9 μmol·kg-1·min-1和24.5±8.2 μmol·kg-1);p = 0.611)或血浆甘油出现率(即STAT和placc的8.5±1.9 vs. 7.9±1.8 μmol·kg-1·min-1;P = .262)。结论:在肥胖、血脂异常和代谢综合征患者中,他汀类药物在休息或长时间中等强度运动(即相当于快走)时不会损害其动员和氧化脂肪的能力。在这些患者中,他汀类药物和运动的结合可以帮助更好地控制他们的血脂异常。
{"title":"Chronic Statin Treatment Does Not Impair Exercise Lipolysis or Fat Oxidation in Exercise-Trained Individuals With Obesity and Dyslipidemia.","authors":"Laura Alvarez-Jimenez, Alfonso Moreno-Cabañas, Felix Morales-Palomo, Juan F Ortega, Ricardo Mora-Rodriguez","doi":"10.1123/ijsnem.2022-0175","DOIUrl":"https://doi.org/10.1123/ijsnem.2022-0175","url":null,"abstract":"<p><strong>Objective: </strong>To determine whether statin medication in individuals with obesity, dyslipidemia, and metabolic syndrome affects their capacity to mobilize and oxidize fat during exercise.</p><p><strong>Methods: </strong>Twelve individuals with metabolic syndrome pedaled during 75 min at 54 ± 13% V˙O2max (5.7 ± 0.5 metabolic equivalents) while taking statins (STATs) or after 96-hr statin withdrawal (PLAC) in a randomized double-blind fashion.</p><p><strong>Results: </strong>At rest, PLAC increased low-density lipoprotein cholesterol (i.e., STAT 2.55 ± 0.96 vs. PLAC 3.16 ± 0.76 mmol/L; p = .004) and total cholesterol blood levels (i.e., STAT 4.39 ± 1.16 vs. PLAC 4.98 ± 0.97 mmol/L; p = .008). At rest, fat oxidation (0.99 ± 0.34 vs. 0.76 ± 0.37 μmol·kg-1·min-1 for STAT vs. PLAC; p = .068) and the rates of plasma appearance of glucose and glycerol (i.e., Ra glucose-glycerol) were not affected by PLAC. After 70 min of exercise, fat oxidation was similar between trials (2.94 ± 1.56 vs. 3.06 ± 1.94 μmol·kg-1·min-1, STA vs. PLAC; p = .875). PLAC did not alter the rates of disappearance of glucose in plasma during exercise (i.e., 23.9 ± 6.9 vs. 24.5 ± 8.2 μmol·kg-1·min-1 for STAT vs. PLAC; p = .611) or the rate of plasma appearance of glycerol (i.e., 8.5 ± 1.9 vs. 7.9 ± 1.8 μmol·kg-1·min-1 for STAT vs. PLAC; p = .262).</p><p><strong>Conclusions: </strong>In patients with obesity, dyslipidemia, and metabolic syndrome, statins do not compromise their ability to mobilize and oxidize fat at rest or during prolonged, moderately intense exercise (i.e., equivalent to brisk walking). In these patients, the combination of statins and exercise could help to better manage their dyslipidemia.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"151-160"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9474017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2023-0037
Nicholas B Tiller, Stuart M Phillips
{"title":"How Skepticism (not Cynicism) Can Raise Scientific Standards and Reform the Health and Wellness Industry.","authors":"Nicholas B Tiller, Stuart M Phillips","doi":"10.1123/ijsnem.2023-0037","DOIUrl":"https://doi.org/10.1123/ijsnem.2023-0037","url":null,"abstract":"","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"174-178"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9884829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2023-0010
Andrew T Askow, Nicholas A Burd
{"title":"Reply to G. Escalante and D. St. Mart.","authors":"Andrew T Askow, Nicholas A Burd","doi":"10.1123/ijsnem.2023-0010","DOIUrl":"https://doi.org/10.1123/ijsnem.2023-0010","url":null,"abstract":"","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"173"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9756277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2022-0236
Nathalia Saffioti Rezende, Giulia Cazetta Bestetti, Luana Farias de Oliveira, Bruna Caruso Mazzolani, Fabiana Infante Smaira, Alina Dumas, Paul Swinton, Bryan Saunders, Eimear Dolan
β-Alanine (BA) is one of the most widely used sport supplements, due to its capacity to improve high-intensity exercise performance by increasing muscle carnosine (MCarn) content, and consequently, the buffering capacity of the muscle. BA is also available in a variety of animal foods, but little is currently known about the influence of dietary BA intake on MCarn. The aim of the current study was to compile a detailed summary of available data on the BA content of commonly consumed foods, and to explore whether associations could be detected between self-reported dietary BA intake and skeletal MCarn in a group of 60 healthy, active, omnivorous men and women. Dietary BA intake was assessed via 3-day food records, and MCarn content assessed by high-performance liquid chromatography. A series of univariate and multivariate linear regression models were used to explore associations between estimated dietary BA and MCarn. No evidence of associations between dietary BA intake and MCarn were identified, with effect sizes close to zero calculated from models accounting for key demographic variables (f2 ≤ 0.02 for all analyses). These findings suggest that capacity to increase MCarn via dietary strategies may be limited, and that supplementation may be required to induce increases of the magnitude required to improve performance.
{"title":"Dietary β-Alanine Intake Assessed by Food Records Does Not Associate With Muscle Carnosine Content in Healthy, Active, Omnivorous Men and Women.","authors":"Nathalia Saffioti Rezende, Giulia Cazetta Bestetti, Luana Farias de Oliveira, Bruna Caruso Mazzolani, Fabiana Infante Smaira, Alina Dumas, Paul Swinton, Bryan Saunders, Eimear Dolan","doi":"10.1123/ijsnem.2022-0236","DOIUrl":"https://doi.org/10.1123/ijsnem.2022-0236","url":null,"abstract":"<p><p>β-Alanine (BA) is one of the most widely used sport supplements, due to its capacity to improve high-intensity exercise performance by increasing muscle carnosine (MCarn) content, and consequently, the buffering capacity of the muscle. BA is also available in a variety of animal foods, but little is currently known about the influence of dietary BA intake on MCarn. The aim of the current study was to compile a detailed summary of available data on the BA content of commonly consumed foods, and to explore whether associations could be detected between self-reported dietary BA intake and skeletal MCarn in a group of 60 healthy, active, omnivorous men and women. Dietary BA intake was assessed via 3-day food records, and MCarn content assessed by high-performance liquid chromatography. A series of univariate and multivariate linear regression models were used to explore associations between estimated dietary BA and MCarn. No evidence of associations between dietary BA intake and MCarn were identified, with effect sizes close to zero calculated from models accounting for key demographic variables (f2 ≤ 0.02 for all analyses). These findings suggest that capacity to increase MCarn via dietary strategies may be limited, and that supplementation may be required to induce increases of the magnitude required to improve performance.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"133-140"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9827054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2022-0177
Ian A J Darragh, Lorraine O'Driscoll, Brendan Egan
This study investigated within-subject variability in the circulating metabolome under controlled conditions, and whether divergent exercise training backgrounds were associated with alterations in the circulating metabolome assessed in resting samples. Thirty-seven men comprising of endurance athletes (END; body mass, 71.0 ± 6.8 kg; fat-free mass index, 16.9 ± 1.1 kg/m2), strength athletes (STR; 94.5 ± 8.8 kg; 23.0 ± 1.8 kg/m2), and recreationally active controls (CON; 77.6 ± 7.7 kg; 18.1 ± 1.0 kg/m2) provided blood samples after an overnight fast on two separate occasions controlled for time of day of sampling, recent dietary intake, time since last meal, and time since last exercise training session. A targeted profile of metabolites, performed using liquid chromatography and mass spectrometry on plasma samples, identified 166 individual metabolites and metabolite features, which were analyzed with intraclass correlation coefficients, a multilevel principal component analysis, and univariate t tests adjusted for multiple comparisons. The median intraclass correlation coefficient was .49, with 46 metabolites displaying good reliability and 31 metabolites displaying excellent reliability. No difference in the abundance of any individual metabolite was identified within groups when compared between visits, but a combined total of 44 metabolites were significantly different (false discovery rate <0.05) between groups (END vs. CON, 42 metabolites; STR vs. CON, 10 metabolites; and END vs. STR, five metabolites). Under similar measurement conditions, the reliability of resting plasma metabolite concentrations varies largely at the level of individual metabolites with ∼48% of metabolites displaying good-to-excellent reliability. However, a history of exercise training was associated with alterations in the abundance of ∼28% of metabolites in the targeted profile employed in this study.
{"title":"Within-Subject Variability and the Influence of Exercise Training History on the Resting Plasma Metabolome in Men.","authors":"Ian A J Darragh, Lorraine O'Driscoll, Brendan Egan","doi":"10.1123/ijsnem.2022-0177","DOIUrl":"https://doi.org/10.1123/ijsnem.2022-0177","url":null,"abstract":"<p><p>This study investigated within-subject variability in the circulating metabolome under controlled conditions, and whether divergent exercise training backgrounds were associated with alterations in the circulating metabolome assessed in resting samples. Thirty-seven men comprising of endurance athletes (END; body mass, 71.0 ± 6.8 kg; fat-free mass index, 16.9 ± 1.1 kg/m2), strength athletes (STR; 94.5 ± 8.8 kg; 23.0 ± 1.8 kg/m2), and recreationally active controls (CON; 77.6 ± 7.7 kg; 18.1 ± 1.0 kg/m2) provided blood samples after an overnight fast on two separate occasions controlled for time of day of sampling, recent dietary intake, time since last meal, and time since last exercise training session. A targeted profile of metabolites, performed using liquid chromatography and mass spectrometry on plasma samples, identified 166 individual metabolites and metabolite features, which were analyzed with intraclass correlation coefficients, a multilevel principal component analysis, and univariate t tests adjusted for multiple comparisons. The median intraclass correlation coefficient was .49, with 46 metabolites displaying good reliability and 31 metabolites displaying excellent reliability. No difference in the abundance of any individual metabolite was identified within groups when compared between visits, but a combined total of 44 metabolites were significantly different (false discovery rate <0.05) between groups (END vs. CON, 42 metabolites; STR vs. CON, 10 metabolites; and END vs. STR, five metabolites). Under similar measurement conditions, the reliability of resting plasma metabolite concentrations varies largely at the level of individual metabolites with ∼48% of metabolites displaying good-to-excellent reliability. However, a history of exercise training was associated with alterations in the abundance of ∼28% of metabolites in the targeted profile employed in this study.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"141-150"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9527855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2022-0229
George Wilson, Carl Langan-Evans, Dan Martin, Andreas M Kasper, James P Morton, Graeme L Close
Jockeys are unique given that they make weight daily and, therefore, often resort to fasting and dehydration. Through increasing daily food frequency (during energy deficit), we have reported short-term improvements in jockey's body composition. While these changes were observed over 6-12 weeks with food provided, it is unclear whether such improvements can be maintained over an extended period during free-living conditions. We, therefore, assessed jockeys over 5 years using dual X-ray absorptiometry, resting metabolic rate, and hydration measurements. Following dietary and exercise advice, jockeys reduced fat mass from baseline of 7.1 ± 1.4 kg to 6.1 ± 0.7 kg and 6.1 ± 0.6 kg (p < .001) at Years 1 and 5, respectively. In addition, fat-free mass was maintained with resting metabolic rate increasing significantly from 1,500 ± 51 kcal/day at baseline to 1,612 ± 95 kcal/day and 1,620 ± 92 kcal/day (p < .001) at Years 1 and 5, respectively. Urine osmolality reduced from 816 ± 236 mOsmol/L at baseline to 564 ± 175 mOsmol/L and 524 ± 156 mOsmol/L (p < .001) at Years 1 and 5, respectively. The percent of jockeys consuming a regular breakfast significantly increased from 48% at baseline to 83% (p = .009) and 87% (p = .003) at Years 1 and 5, alongside regular lunch from 35% to 92% (p < .001) and 96% (p < .001) from baseline to Years 1 and 5, respectively. In conclusion, we report that improved body composition can be maintained in free-living jockeys over a 5-year period when appropriate guidance has been provided.
{"title":"Longitudinal Changes in Body Composition and Resting Metabolic Rate in Male Professional Flat Jockeys: Preliminary Outcomes and Implications for Future Research Directions.","authors":"George Wilson, Carl Langan-Evans, Dan Martin, Andreas M Kasper, James P Morton, Graeme L Close","doi":"10.1123/ijsnem.2022-0229","DOIUrl":"https://doi.org/10.1123/ijsnem.2022-0229","url":null,"abstract":"<p><p>Jockeys are unique given that they make weight daily and, therefore, often resort to fasting and dehydration. Through increasing daily food frequency (during energy deficit), we have reported short-term improvements in jockey's body composition. While these changes were observed over 6-12 weeks with food provided, it is unclear whether such improvements can be maintained over an extended period during free-living conditions. We, therefore, assessed jockeys over 5 years using dual X-ray absorptiometry, resting metabolic rate, and hydration measurements. Following dietary and exercise advice, jockeys reduced fat mass from baseline of 7.1 ± 1.4 kg to 6.1 ± 0.7 kg and 6.1 ± 0.6 kg (p < .001) at Years 1 and 5, respectively. In addition, fat-free mass was maintained with resting metabolic rate increasing significantly from 1,500 ± 51 kcal/day at baseline to 1,612 ± 95 kcal/day and 1,620 ± 92 kcal/day (p < .001) at Years 1 and 5, respectively. Urine osmolality reduced from 816 ± 236 mOsmol/L at baseline to 564 ± 175 mOsmol/L and 524 ± 156 mOsmol/L (p < .001) at Years 1 and 5, respectively. The percent of jockeys consuming a regular breakfast significantly increased from 48% at baseline to 83% (p = .009) and 87% (p = .003) at Years 1 and 5, alongside regular lunch from 35% to 92% (p < .001) and 96% (p < .001) from baseline to Years 1 and 5, respectively. In conclusion, we report that improved body composition can be maintained in free-living jockeys over a 5-year period when appropriate guidance has been provided.</p>","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"161-168"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9472363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1123/ijsnem.2022-0251
Guillermo Escalante, Dean St Mart
participants
{"title":"Comment on: \"Creatine Monohydrate Supplementation, but not Creatyl-L-Leucine Increased Muscle Creatine Content in Healthy Young Adults: A Double-Blind Placebo-Controlled Trial\".","authors":"Guillermo Escalante, Dean St Mart","doi":"10.1123/ijsnem.2022-0251","DOIUrl":"https://doi.org/10.1123/ijsnem.2022-0251","url":null,"abstract":"participants","PeriodicalId":14334,"journal":{"name":"International journal of sport nutrition and exercise metabolism","volume":"33 3","pages":"169-172"},"PeriodicalIF":2.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9756278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}