Sports nutrition is a constantly evolving field with hundreds of research papers published annually. In the year 2017 alone, 2082 articles were published under the key words ‘sport nutrition’. Consequently, staying current with the relevant literature is often difficult. This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in 2004 and updated in 2010. It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. As such, this paper provides an overview of: 1.) How ergogenic aids and dietary supplements are defined in terms of governmental regulation and oversight; 2.) How dietary supplements are legally regulated in the United States; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of nutritional approaches to augment skeletal muscle hypertrophy and the potential ergogenic value of various dietary and supplemental approaches. This updated review is to provide ISSN members and individuals interested in sports nutrition with information that can be implemented in educational, research or practical settings and serve as a foundational basis for determining the efficacy and safety of many common sport nutrition products and their ingredients.
The purpose of this study was to examine the effects of a commercially available thermogenic product (TP) on resting energy expenditure (REE) and hemodynamic variables in a randomized, double-blind, placebo (PL)-controlled study. Eight male (age: 23.0 ± 3.70 years, weight: 95.77 ± 16.44 kg, height: 182.4 ± 7.87 cm) and 10 female (age: 23.6 ± 4.81 years, weight: 67.25 ± 5.74 kg, height: 172.42 ± 10.31 cm) physically active individuals participated in this study. Participants reported to the laboratory on a 10-h fast and performed baseline testing on REE, heart rate, and blood pressure. Participants were then randomly assigned to ingest 3 capsules of either an experimental TP or a vitamin E PL. Criterion variables were then measured at 1-, 2-, and 3-h post ingestion. Data were analyzed by 2-factor analysis of variance (ANOVA) using SPSS, version 16.0 (SPSS Inc., Chicago, Ill.). Supplementation of the TP resulted in a significant main effect for time (p = 0.040) and for interaction (p < 0.01) in REE when compared with PL. Post hoc analysis revealed that there was no significant difference (p > 0.05) between groups at baseline, but the TP group was significantly higher (p < 0.01) than the PL group at 1-, 2-, and 3-h post, with peak values being achieved at 2-h post time point. The TP group also experienced an overall increase in REE by 17.3%, 19.6%, and 15.3% at the 1-, 2-, and 3-h time points, respectively, over baseline values. Conversely, the PL group experienced a reduction in REE by 2.5%, 1.8%, and 0.3% at the same time points compared with baseline values. There was no significant change in heart rate, systolic blood pressure, or diastolic blood pressure in either group. Taken on a daily basis, a TP may increase overall energy expenditure. Caloric expenditure significantly increased at all 3 time points in the TP group, whereas the PL group experienced no change in energy expenditure.
It has been hypothesized that performing aerobic exercise after an overnight fast accelerates the loss of body fat. The purpose of this study was to investigate changes in fat mass and fat-free mass following four weeks of volume-equated fasted versus fed aerobic exercise in young women adhering to a hypocaloric diet. Twenty healthy young female volunteers were randomly assigned to 1 of 2 experimental groups: a fasted training (FASTED) group that performed exercise after an overnight fast (n = 10) or a post-prandial training (FED) group that consumed a meal prior to exercise (n = 10). Training consisted of 1 hour of steady-state aerobic exercise performed 3 days per week. Subjects were provided with customized dietary plans designed to induce a caloric deficit. Nutritional counseling was provided throughout the study period to help ensure dietary adherence and self-reported food intake was monitored on a regular basis. A meal replacement shake was provided either immediately prior to exercise for the FED group or immediately following exercise for the FASTED group, with this nutritional provision carried out under the supervision of a research assistant. Both groups showed a significant loss of weight (P = 0.0005) and fat mass (P = 0.02) from baseline, but no significant between-group differences were noted in any outcome measure. These findings indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training.
The role of nutrient timing both before and after daily training sessions is now a major part of the nutritional recommendations for athletes to maximize training adaptations. However, there still exists some questions on the ideal macronutrient selection for these pre- and post-workout meals. PURPOSE: To investigate the potential effects of protein vs. carbohydrate ingestion in collegiate female basketball players. METHODS: 14 (20.2 ± 1.4 years, 169.4 ± 5.8 cm, 67.5 ± 6.1 kg, 27.1 ± 4.4 %BF) NCAA Division III female basketball players were matched by weight and randomly assigned in a double-blind manner to consume 24 grms whey protein (WP) or 24 grms maltodextrin (MD) pre- and post-exercise for eight weeks. Subjects participated in a supervised 4-day per week undulating periodized resistance and anaerobic training program. At 0 and 8-weeks, subjects underwent DEXA body composition analysis and upper- and lower-body 1RM strength, vertical jump, 5-10-5, and broad jump testing. Data were analyzed using repeated measures ANOVA (p≤0.05) and are presented as mean ± SD changes. RESULTS: Significant group x time interaction effects were observed among groups for bench press 1RM (p = 0.043) and DEXA lean mass (p = 0.026) indicating that the WP group resulted in a more substantial training adaptations over the MD group. A significant time effect (p < 0.05) was observed for DEXA %BF (%change: -4.87 ± 4%), DEXA fat mass (%change: -4.33 ± 5%), leg press 1RM (%change: 13.57 ± 7%), vertical jump (%change: 9.95 ± 6%), 5-10-5 (%change: -3.1 ± 2%), and broad jump (%change: 3.9 ± 4%) suggesting that the stimulus of the training protocol was adequate to promote anaerobic physiological adaptations. CONCLUSIONS: In regards to nutrient timing, our results suggest that whey protein ingestion both pre- and post- training is a greater stimulus for increases in lean mass in female collegiate anaerobic athletes as compared to the ingestion of carbohydrates. This translated into a significant difference in upper body 1RM strength, however, despite significant training adaptations occurring over the 8 week trial, no significant differences occurred in lower body strength, vertical and broad jump, and 5-10-5 time between WP and MD groups. Supplements provided by Clinically Proven Consultants & Associates, Study supported by UMHB Graduate Research Grant
Kerksick, CM, Wilborn, CD, Campbell, WI, Harvey, TM, Marcello, BM, Roberts, MD, Parker, AG, Byars, AG, Greenwood, LD, Almada, AL, Kreider, RB, and Greenwood, M. The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations. J Strength Cond Res 23(9): 2673-2682, 2009-Coingestion of D-pinitol with creatine (CR) has been reported to enhance creatine uptake. The purpose of this study was to evaluate whether adding D-pinitol to CR affects training adaptations, body composition, whole-body creatine retention, and/or blood safety markers when compared to CR ingestion alone after 4 weeks of resistance training. Twenty-four resistance trained males were randomly assigned in a double-blind manner to creatine + pinitol (CRP) or creatine monohydrate (CR) prior to beginning a supervised 4-week resistance training program. Subjects ingested a typical loading phase (i.e., 20 g/d−1 for 5 days) before ingesting 5 g/d−1 the remaining 23 days. Performance measures were assessed at baseline (T0), week 1 (T1), and week 4 (T2) and included 1 repetition maximum (1RM) bench press (BP), 1RM leg press (LP), isokinetic knee extension, and a 30-second Wingate anaerobic capacity test. Fasting blood and body composition using dual-energy x-ray absorptiometry (DEXA) were determined at T1 and T3. Data were analyzed by repeated measures analysis of variance (ANOVA). Creatine retention increased (p < 0.001) in both groups as a result of supplementation but was not different between groups (p > 0.05). Significant improvements in upper- and lower-body strength and body composition occurred in both groups. However, significantly greater increases in lean mass and fat-free mass occurred in the CR group when compared to CRP (p <0.05). Adding D-pinitol to creatine monohydrate does not appear to facilitate further physiological adaptations while resistance training. Creatine monohydrate supplementation helps to improve strength and body composition while resistance training. Data from this study assist in determining the potential role the addition of D-pinitol to creatine may aid in facilitating training adaptations to exercise.
0535 PURPOSE: To examine the effects of the Curves fitness and diet program on general markers of health. METHODS: 123 sedentary women (38.7 ± 8 yr; 93.2 ± 19 kg; 44.8 ± 4.8 % body fat) participated in a 14-wk exercise and diet program. Based on baseline testing, subjects were randomly assigned to an exercise and no diet group (END); an exercise and high calorie (2,600 kcals/d) mixed diet group (HCD); or, a low calorie high carbohydrate (HCHO), high protein (HP), or very high protein (VHP) diet group. The diets involved consuming 1,200 kcal/d for 2-wks and 1,600 kcal/d for 8 wks. Subjects then ingested 2,600 kcal/d and 1,200 kcal/d diet at 3/2, 3/2, 5/2, & 10/2 day intervals in an attempt to maintain weight loss. Diets were standardized with 30% dietary fat with carbohydrate intake ranging from 40–55% on the HCD and HCO diets and protein intake ranging from 50–63% on the HP and VHP diets. Subjects participated in a supervised 30-min resistance training circuit program that was interspersed with calisthenic exercises 3-d per week. At 0, 2, 10, 10.4 and 14 weeks, subjects donated fasting blood samples and had hip and waist measurements determined. Subjects also reported health status to a nurse on a weekly basis. Data were analyzed by repeated measures ANOVA and are presented as means ± SD from baseline at week 2, 10, 10.4, and 14 of the study, respectively. RESULTS: Total cholesterol (−20.2 ± 24; −11.6 ± 26; −14.5 ± 25; −7.2 ± 25 mg/dl, p<0.001), LDL (−12.7 ± 19; −8.1 ± 22; −10.5 ± 19; −6.7 ± 21 mg/dl, p<0.001), and the ratio of total cholesterol/HDL (−0.16 ± 0.5; −0.07 ± 0.5; −0.09 ± 0.5, −0.06 ± 0.6, p<003) significantly decreased with no significant differences observed among groups. Waist (−2.9 ± 5; −5.9 ± 5; −6.9 ± 5, −7.0 ± 5 cm, p<0.001), hip (−2.1 ± 5; −4.0 ± 5; −4.3 ± 4, −4.7 ± 5 cm, p<0.001), and the ratio of waist to hip measurements (−0.01 ± 0.07; −0.02 ± 0.05; −0.03 ± 0.04, −0.03 ± 0.04, p<0.001) decreased resulting in an overall reduction in the waist to hip ratio from 0.84 ± 0.05 (Very High Risk) to 0.81 ± 0.05 (High Risk). No significant differences were observed in serum glucose, triglycerides, total protein, BUN, creatinine, BUN/creatinine ratio, uric acid, AST, ALT, CK, LDH, GGT, albumin, globulin, sodium, chloride, calcium, carbon dioxide, total bilirubin, alkaline phosphatase, hemoglobin, hematocrit, red blood cell counts, MCV, MCH, MCHC, RDW, white blood cell counts, neutrophils, lymphocytes, monocytes, eosinophils, or baosphils. No clinically significant side effects were reported. CONCLUSIONS: The Curves program promotes improvements in blood lipid profiles and a reduction in waist to hip ratio without adversely affecting general markers of health.
It has been hypothesized that performing aerobic exercise after an overnight fast accelerates the loss of body fat. The purpose of this study was to investigate changes in fat mass and fat-free mass following four weeks of volume-equated fasted versus fed aerobic exercise in young women adhering to a hypocaloric diet. Twenty healthy young female volunteers were randomly assigned to 1 of 2 experimental groups: a fasted training (FASTED) group that performed exercise after an overnight fast (n = 10) or a post-prandial training (FED) group that consumed a meal prior to exercise (n = 10). Training consisted of 1 hour of steady-state aerobic exercise performed 3 days per week. Subjects were provided with customized dietary plans designed to induce a caloric deficit. Nutritional counseling was provided throughout the study period to help ensure dietary adherence and self-reported food intake was monitored on a regular basis. A meal replacement shake was provided either immediately prior to exercise for the FED group or immediately following exercise for the FASTED group, with this nutritional provision carried out under the supervision of a research assistant. Both groups showed a significant loss of weight (P = 0.0005) and fat mass (P = 0.02) from baseline, but no significant between-group differences were noted in any outcome measure. These findings indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training.
'%3e%3cg id='e'%3e%3cg id='c' fill='none' stroke='%23fff' stroke-width='2'%3e%3cpath id='b' d='M0 1h26M1 10V5h8v4h8V5h-5M4 9h2m20 0h-5V5h8m0-5v9h8V0m-4 0v9' transform='scale(1.4)'/%3e%3cpath id='a' d='M0 7h9m1 0h9' transform='scale(2.8)'/%3e%3cuse xlink:href='%23a' y='120'/%3e%3cuse xlink:href='%23b' y='145.2'/%3e%3c/g%3e%3cg id='d'%3e%3cuse xlink:href='%23c' x='56'/%3e%3cuse xlink:href='%23c' x='112'/%3e%3cuse xlink:href='%23c' x='168'/%3e%3c/g%3e%3c/g%3e%3cuse xlink:href='%23d' x='168'/%3e%3cuse xlink:href='%23e' x='392'/%3e%3c/g%3e%3cg fill='%23da0000' transform='matrix(45 0 0 45 315 180)'%3e%3cg id='f'%3e%3cpath d='M-.548.836A.912.912 0 0 0 .329-.722 1 1 0 0 1-.548.836'/%3e%3cpath d='M.618.661A.764.764 0 0 0 .422-.74 1 1 0 0 1 .618.661M0 1l-.05-1L0-.787a.31.31 0 0 0 .118.099V-.1l-.04.993zM-.02-.85 0-.831a.144.144 0 0 0 .252-.137A.136.136 0 0 1 0-.925'/%3e%3c/g%3e%3cuse xlink:href='%23f' transform='scale(-1 1)'/%3e%3c/g%3e%3c/svg%3e)