This study examined whether supplementing the diet with a commercial supplement containing zinc magnesium aspartate (ZMA) during training affects zinc and magnesium status, anabolic and catabolic hormone profiles, and/or training adaptations. Forty-two resistance trained males (27 +/- 9 yrs; 178 +/- 8 cm, 85 +/- 15 kg, 18.6 +/- 6% body fat) were matched according to fat free mass and randomly assigned to ingest in a double blind manner either a dextrose placebo (P) or ZMA 30-60 minutes prior to going to sleep during 8-weeks of standardized resistance-training. Subjects completed testing sessions at 0, 4, and 8 weeks that included body composition assessment as determined by dual energy X-ray absorptiometry, 1-RM and muscular endurance tests on the bench and leg press, a Wingate anaerobic power test, and blood analysis to assess anabolic/catabolic status as well as markers of health. Data were analyzed using repeated measures ANOVA. Results indicated that ZMA supplementation non-significantly increased serum zinc levels by 11 - 17% (p = 0.12). However, no significant differences were observed between groups in anabolic or catabolic hormone status, body composition, 1-RM bench press and leg press, upper or lower body muscular endurance, or cycling anaerobic capacity. Results indicate that ZMA supplementation during training does not appear to enhance training adaptations in resistance trained populations.
Objective Commercial weight loss programs offer consumers a pre‐programmed means of managing weight. However, such programs differ in dietary advice and physical activity recommendations. The aim of this investigation was compare the Curves ® Complete 90‐day Challenge (CC), Weight Watchers ® Points Plus (WW), Jenny Craig ® At Home (JC), and Nutrisystem ® Advance Select™ (NS) on metabolic syndrome (MetS) and weight loss. Methods We examined 133 sedentary overweight women (47±11 yr, 86±14 kg, 35.4±6 kg/m 2 ) randomized into CC (n=29), WW (n=29), JC (n=27), NS (n=28), or control (n=20) for 12‐wks. Body mass and MetS were obtained at baseline and follow‐up (12 w). The primary outcome was MetS expressed as a categorical variable and summed z‐score (zMetS) as a continuous variable. Secondary outcomes included total caloric intake, body mass, respective anthropometry and measured physical activity (PA). Data were analyzed using a chi‐square and general linear model covaried for age and prevalence of MetS at baseline. Data are mean ± SD and mean change ± 95% CI when applicable. Results We observed significant reductions in total energy intake for all treatment groups except Control (−103 kcal, 95% CI, −277, 70): CC (−413 kcal, 95% CI, −573, −254), WW (−531 kcals, 95% CI, −675, −387), JC (−604 kcal, 95% CI, −753, −455), NS (−631 kcal, 95% CI, −778, −485). While post‐hoc analysis showed JC and NS to be greater than CC, weight loss was similar for all groups (−4.0 ± 4.2 kg). At baseline, the prevalence of MetS was: CC (35%), WW (31%), JC (37%), NS (39%) and control (45%). At follow‐up we observed a significant trend (p=0.008) in reduction of MetS prevalence such that CC (14%) and WW (28%) was significantly lower than JC (42%), NS (50%) and control (55%); however, WW was not significantly different than JC, NS, or control. When expressed as zMetS, only the CC group demonstrated a significant reduction in zMetS (−0.11, 95% CI −0.21, −0.004) vs. WW (−0.89, 95% CI −0.18, 0.02), JC (−0.05, 95% CI −0.16, −.06), NS (−0.06, 95% CI −0.16, 0.05) and control (−0.05, 95% CI, −0.18, 0.07). Other than exercise contained within the CC program, no significant changes were otherwise noted in total PA for any treatment group: CC (4645 MET min/week; 95% CI, −1638, 10929), Weight Watchers (−3361 MET min/week; 95% CI, 3208, 2988), Jenny Craig (−448 MET min/week; 95% CI, −6949, 6053), Nutrisystem (−967 MET min/week; 95% CI, −7401, 5468) or Control (5128 MET min/week; 95% CI, −2529, 12785). Conclusions Notwithstanding the minor differences in energy intake favoring JC and NS, each program demonstrated similar amounts of weight loss. However, a significant reduction in MetS was demonstrated only in CC and WW via categorical analysis and CC via zMetS. Thus, despite recommendations by each program to increase PA, the program including a structured fitness routine in conjunction with diet exhibited the greatest impact on changes in MetS. Support or Funding Information Curves International
To determine the effects of 12 weeks of resistance exercise with MyoViveo and/or colostrum supplementation, 19 male and female recreationally weighttrained subjects (X ‐ SE; age = 28.3 ‐ 6.9 yrs; hgt = 68.2 ‐ 3.8 cm) were divided into MyoViveo + colostrum (n = 4), MyoViveo + casein & whey (n = 4), colostrum + casein & whey (n = 6), and casein & whey (n = 5) groups. All groups similarly increased (p < .05) 1 repetition maximum (RM) leg press (kg; pre = 158.6 ‐ 12.8, post = 189.3 ‐ 11.3), body mass (kg; pre = 79.0 ‐ 3.2, post = 80.7 ‐ 3.8), and lean body mass (kg; pre = 60.1 ‐ 3.1, post = 62.2 ‐ 2.8). Increases were observed for peak force (N; all loads), peak velocity (m . s -1 ; 70% & 40% 1 RM), and peak power (W; 70% & 40% 1 RM) for all groups for the leg press exercise, with no differences between groups. When performance data were adjusted for body mass, lean body mass, lower body lean mass as determined by DEXA, or % change, no group differences were observed. Relative (%) fiber type content, cross-sectional areas (mm 2 ), % fiber type areas, or % myosin heavy chain expression did not change for any group. These data suggest that MyoViveo and colostrum supplementation have no greater effect on cellular and performance adaptations when compared to casein and whey protein.
Metabolic conditions, such as gout, can result from elevated uric acid (UA) levels. Consuming high-purine meals increases UA levels. Therefore, people with hyperuricemia typically must avoid ingesting such foods. Polyphenols have been shown to reduce uric acid levels and tart cherries (TCs) are a rich source of phenolic and anthocyanin compounds. This proof-of-concept study evaluated whether ingesting TCs with a purine-rich meal affects the uricemic response.
Proper training, maintaining a positive energy balance, adhering to proper nutrient timing, and obtaining adequate rest and recovery form the foundation for optimal performance. Therefore, this chapter begins with a description of factors associated with optimal performance of the strength/power athlete. Section two focuses on preexercise nutrition and how it can prepare the athlete for action and enhance the training response whereas section three addresses the nutritional importance in delaying fatigue. The next section addresses the importance of postexercise nutrition and how it can aid in recovery and prepare the athlete for subsequent exercise sessions, and the final section provides training and nutritional recommendations that serve as the foundation for a successful strength/power athlete.
Phaeodactylum tricornutum (PT) is a microalgae extract that contains fucoxanthin and has been shown to enhance cognitive function in younger populations. The present study assessed if PT supplementation affects cognition in healthy, young-old, physically active adults with self-perceptions of cognitive and memory decline. Methods: Forty-three males and females (64.3 ± 6.0 years, 79.8 ± 16.0 kg, 27.0 ± 4.0 kg/m2) with perceptions of cognitive and memory decline completed the double-blind, randomized, parallel-arm, placebo-controlled intervention clinical trial. Participants were counterbalanced by sex and BMI and randomly allocated to their respective 12-week supplementation interventions, which were either the placebo (PL) or 1100 mg/day of PT containing 8.8 mg of fucoxanthin (FX). Fasting blood samples were collected, and cognitive assessments were performed during the testing session at 0, 4, and 12 weeks of intervention. The data were analyzed by multivariate and univariate general linear model (GLM) analyses with repeated measures, pairwise comparisons, and mean changes from baseline analysis with 95% confidence intervals (CIs) to assess the clinical significance of the findings. Results: FX supplementation significantly affected (p < 0.05) or exhibited tendencies toward significance (p > 0.05 to p < 0.10 with effect sizes ranging from medium to large) for word recall, picture recognition reaction time, Stroop color–word test, choice reaction time, and digit vigilance test variables. Additionally, FX supplementation promoted a more consistent clinical improvement from baseline values when examining mean changes with 95% CIs, although most differences were seen over time rather than between groups. Conclusions: The results demonstrate some evidence that FX supplementation can improve working and secondary memory, vigilance, attention, accuracy, and executive function. There was also evidence that FX promoted more positive effects on insulin sensitivity and perceptions about sleep quality with no negative effects on clinical blood panels or perceived side effects. Additional research should investigate how FX may affect cognition in individuals perceiving memory and cognitive decline. Registered clinical trial #NCT05759910.
Earnest, C.P., S. Lancaster, C. Rasmussen, C. Kerksick, A. Lucia, M. Greenwood, A. Almada, P. Cowan, and R. Kreider. Low vs. high glycemic index carbohydrate gel ingestion during simulated 64-km cycling time trial performance. J. Strength Cond. Res. 18(3):466–472. 2004.—We examined the effect of low and high glycemic index (GI) carbohydrate (CHO) feedings during a simulated 64-km cycling time trial (TT) in nine subjects ([mean ± SEM], age = 30 ± 1 years; weight = 77.0 ± 2.6 kg). Each rider completed three randomized, double blind, counterbalanced, crossover rides, where riders ingested 15 g of low GI (honey; GI = 35) and high GI (dextrose; GI = 100) CHO every 16 km. Our results showed no differences between groups for the time to complete the entire TT (honey = 128 minutes, 42 seconds ± 3.6 minutes; dextrose = 128 minutes, 18 seconds ± 3.8 minutes; placebo = 131 minutes, 18 seconds ± 3.9 minutes). However, an analysis of total time alone may not portray an accurate picture of TT performance under CHO-supplemented conditions. For example, when the CHO data were collapsed, the CHO condition (128 minutes, 30 seconds) proved faster than placebo condition (131 minutes, 18 seconds; p < 0.02). Furthermore, examining the percent differences and 95% confidence intervals (CI) shows the two CHO conditions to be generally faster, as the majority of the CI lies in the positive range: placebo vs. dextrose (2.36% [95% CI; -0.69, 4.64]) and honey (1.98% [95% CI; -0.30, 5.02]). Dextrose vs. honey was 0.39% (95% CI; -3.39, 4.15). Within treatment analysis also showed that subjects generated more watts (W) over the last 16 km vs. preceding segments for dextrose (p < 0.002) and honey (p < 0.0004) treatments. When the final 16-km W was expressed as a percentage of pretest maximal W, the dextrose treatment was greater than placebo (p < 0.05). A strong trend was noted for the honey condition (p < 0.06), despite no differences in heart rate (HR) or rate of perceived exertion (RPE). Our results show a trend for improvement in time and wattage over the last 16 km of a 64-km simulated TT regardless of glycemic index.
1485 Anecdotal reports suggest that creatine supplementation during intense training in the heat may alter electrolyte status and/or promote dehydration. This study examined the effects creatine supplementation on fluid and electrolyte status during two phases of pre-season college football training. 53 Division IA football players (19.9±0.2 yrs; 185±1 cm, 103±2.6 kg) participated in the first phase of a long-term open label study to evaluate the medical safety of creatine supplementation. 34 subjects ingested a commercially available supplement containing 15.75 g/d of creatine for 5-d followed by ingesting 5.25 g/d of creatine for 20-d. Remaining subjects were provided a carbohydrate/protein supplement containing no creatine. Supplements were administered following daily training sessions. Training during phase 1 consisted of 4-5 d/wk (70±7 min per workout) of resistance-training indoors (28±1°C, 79±2% RH) and sprint/agility conditioning outdoors (32±0.9°C, 84±3% RH). Training during phase II involved subjects practicing 2 to 3 times per day for 1.5 to 3.5 h (207±17 min/d, 6 d/wk) during 17-d of preseason football camp in which environmental conditions ranged from 29 to 37°C, 58 to 91% R.H. (33.7±0.6°C, 79±2.4% R.H.). During phase II, subjects in the creatine group ingested a carbohydrate/protein supplement containing 8.3 g/d of creatine. Prior to and following each phase of training, body weight, total body water via bioelectrical impedance, fasting blood, and 24-hr urine samples were obtained. During camp, pre-and post practice body weights were recorded on all players (n=100). Data were analyzed by repeated measures ANOVA. Results revealed no significant interactions (p>0.05) between groups in total body weight, total body water; urine output, specific gravity; hematocrit, hemoglobin, blood volume, plasma volume or serum sodium, chloride, potassium, phosphorus, calcium, total protein, and albumin. No significant differences were observed between creatine users and non-users in weight loss (kg or %) during practices. Results indicate that creatine supplementation during 25-d of preseason conditioning and 17-d of football camp in an hot/humid environment does not affect markers of fluid or electrolyte status. Supported by Experimental & Applied Sciences, Golden CO & University of Memphis.
Objective: To determine whether sedentary obese women with elevated levels of homeostatic model assessment (HOMA) insulin resistance (ie, > 3.5) experience greater benefits from an exercise + higher-carbohydrate (HC) or carbohydrate-restricted weight loss program than women with lower HOMA levels. Methods: 221 women (age, 46.5 ± 12 years; body weight, 90.3 ± 16 kg; body mass index, 33.8 ± 5 kg/m2) participated in a 10-week supervised exercise and weight loss program. The fitness program involved 30 minutes of circuit-style resistance training 3 days per week. Subjects were prescribed low-fat (30%) isoenergetic diets that consisted of 1200 kcals per day for 1 week (phase 1) and 1600 kcals per day for 9 weeks (phase 2) with HC or higher protein (HP). Fasting blood samples, body composition, anthropometry, resting energy expenditure, and fitness measurements were obtained at 0 and 10 weeks. Subjects were retrospectively stratified into lower (LH) or higher (HH) than 3.5 HOMA groups. Data were analyzed by multivariate analysis of variance with repeated measures and are presented as mean ± standard deviation changes from baseline. Results: Baseline HOMA levels in the LH group were significantly lower than those in the HH group (LH, 0.6 ± 0.7; HH, 6.3 ± 3.4; P = 0.001). Diet and training significantly decreased body weight (−3.5 ± 3 kg), fat mass (−2.7 ± 3 kg), blood glucose (−3%), total cholesterol (−4.5%), low-density lipoproteins (−5%), triglycerides (−5.9%), systolic blood pressure (−2.6%), and waist circumference (−3.7%), while increasing peak aerobic capacity (7.3%). Subjects in the HP group experienced greater weight loss (−4.4 ± 3.6 kg vs −2.6 ± 2.9 kg), fat loss (−3.4 ± 2.7 kg vs −1.7 ± 2.0 kg), reductions in serum glucose (3% vs 2%), and decreases in serum leptin levels (−30.8% vs −10.8%) than those in the HC group. Participants in the HH (−14.1%) and HP-HH (−21.6%) groups observed the greatest reduction in serum blood glucose. Conclusion: A carbohydrate-restricted diet promoted more favorable changes in weight loss, fat loss, and markers of health in obese women who initiated an exercise program compared with a diet higher in carbohydrate. Additionally, obese women who initiated training and dieting with higher HOMA levels experienced greater reductions in blood glucose following an HP diet.
This study examined whether genetic profile influences response to a diet and exercise intervention. 53 sedentary women (38±12 yrs, 80.8±13.9 kg) were randomized to a control group (C) or exercise + diet groups. Those in exercise groups performed circuit resistance‐exercise (4 d/wk) and walked (10,000 steps, 3 d/wk). Diets were 1,500 kcal/d with 20:35:45 (CI), 30:25:45 (CII) or 55:30:15 (AHA) percentages of CHO:FAT: PRO. Buccal cheek swabs were obtained at baseline and analyzed for FABP2, PPARG, ADRB‐79, ADRB3, and ADRB‐46 genes to determine true (T) or false (F) genetic matches to higher CHO or CHO restricted diets. Body weight and DEXA body composition measurements were obtained at 0, 4, 8, 12, 16, 20, and 24 wks. Data were analyzed by MANOVA and are presented as changes from baseline. An overall Wilk's Lambda time x diet (p=0.085) and time x diet x genotype (p=0.102) trend was observed. Univariate analysis revealed significant interaction trends in fat mass (C: 0.39±1.26; CI: T ‐6.16±5.04, F ‐1.58±2.22; CII: T ‐5.03±2.8, F ‐4.2±3.3; AHA: T ‐3.60±2.5, F ‐5.24±4.0 kg, p=0.06) and percent body fat (C: 0.15±1.61; CI: T ‐4.95±4.26, F ‐1.44±2.68; CII: T ‐3.50±3.17, F ‐4.87±3.08; AHA: T ‐3.23±2.81, F ‐4.32±3.43 kg, p=0.10) while weight was not significantly affected (C: 0.92±2.19; CI: T ‐6.75±6.38, F ‐2.22±2.37; CII: T ‐5.64±3.40, F ‐2.74±4.37; AHA: T ‐4.36±2.68, F ‐5.65±4.94 kg, p=0.33). Preliminary findings suggest that women participating in a 6 month diet and exercise program may experience greater changes in body composition when diet type is matched to genetic metabolic profile.
