Factors that contribute to and account for strength and work capacity in a large cohort of recreationally trained adult healthy men with high- and low-strength levels.

The factors that best account for differences in strength across all types of exercise, body types, and training histories are not well understood. The purpose of this study was to assess the effects of strength level and body composition on upper- and lower-body work capacity in adult men. From a cohort of 295 adult men (25.6 ± 7.5 years, 178 ± 8 cm, 85.2 ± 15 kg), low-strength (LS, n = 72) and high-strength (HS, n = 66) samples were selected based on 1 repetition maximum (1RM) bench press (BP) and leg strength (LP) values. Work capacity for each exercise was determined from the product of repetition weight (80% 1RM) and maximum repetitions-to-fatigue (RTF). Body composition was measured using dual-energy x-ray absorptiometry. The HS group was significantly greater than the LS group in total body mass and fat-free mass but not in age, height, fat mass, or %fat. Low-strength and HS groups were not significantly different (p > 0.05) in RTF for either BP (8.7 ± 3.1 vs. 8.3 ± 1.9 reps, respectively) or LP (15.6 ± 7.6 vs. 17.0 ± 6.3 reps, respectively), making the ratio of RTF for BP vs. LP nonsignificant (LS = 2.0 ± 1.0; HS = 2.2 ± 0.9). The HS group produced significantly greater (p < 0.001) absolute and relative work capacities for both BP and LP compared with the LS group. Repetitions-to-fatigue had a greater influence on BP (r2 = 0.74) and LP (r2 = 0.85) work capacities in the LS group than did RepWt (r2 = 0.07 and 0.28, respectively). In the HS group, RTF (r2 = 0.79) had a greater influence than RepWt (r2 = 0.10) on BP work capacity, whereas the 2 components were more similar for LP work capacity (r2 = 0.64 and 0.47, respectively). When evaluated at the same %1RM, muscular endurance is similar across divergent strength levels meaning that work capacity (load × reps) will be greater for HS individuals. Controlling for the influence of body composition variables (e.g., fat or fat-free mass) does not eliminate the difference in work capacity between strength groups suggesting that other factors are accounting for strength expression. Prescribing repetitions against a fixed relative load is largely dependent on exercise type and must be considered by strength and conditioning professionals.

Comparison of Two Diet and Exercise Approaches on Weight Loss and Health Outcomes in Obese Women.

AIM: To compare the efficacy of two popular weight loss approaches on weight loss, body composition, and markers of health in sedentary obese women. METHODS: In total, 51 sedentary women (age 34.5 ± 7.7 yrs.; weight 90.0 ± 14.5 kg; BMI 34.0 ± 5.1 kg/m2; 46.5 ± 7.0% fat) were matched and randomized to participate in the Weight Watchers® Momentum™ (WW) or Curves® (CV) Fitness and Weight Management program for 16 weeks. Participants in the WW group (n = 27) were provided a point-based diet program, received weekly progress checks and counseling, and were encouraged to exercise. Participants in the CV group (n = 24) followed a menu-based higher protein/low-fat diet (1200 kcal/d) for 1 week; 1500 kcal/d diet for 3 weeks; and 2000-2500 kcals/d for 2 weeks that was repeated three times (except the last segment) while participating in a supervised circuit-style resistance training program (3 d/wk). A general linear model (GLM) with repeated measures was used to analyze data and are presented as mean changes from baseline (mean [UL, LL]). RESULTS: Supervised CV training resulted in greater amounts of vigorous and total physical activity. After 16 weeks, both groups lost weight (WW -6.1 [-7.8, -4.6], CV -4.9 [-6.2, -3.2] kg, p = 0.264). Participants in the CV group observed greater reductions in fat mass (WW -2.9 [-6.7, -0.2], CV -6.4 [-9.2, -3.6] kg, p = 0.081) and increases in lean mass (WW -2.5 [-4.3, -0.7], CV 1.3 [-0.6, 3.2] kg, p = 0.005) resulting in more favorable changes in percent body fat (WW -1.4 [-4.1, 1.2], CV -4.7 [-7.5, -1.8]%, p = 0.098). Both groups observed improvements in peak aerobic capacity and muscular endurance, although bench press lifting volume was greater in the CV group. Those in the CV group experienced a greater increase in HDLc and reduction in the CHL-HDLc ratio and triglycerides. CONCLUSION: Both interventions promoted weight loss and improvements in fitness and markers of health. The CV program, which included supervised resistance training and higher protein diet menus, promoted greater fat loss, increases in lean mass, and improvements in percent body fat and blood lipids. TRIAL REGISTRATION: clinicaltrials.gov, #NCT04372771, registered retrospectively 1 May 2020.

Bioactive properties and clinical safety of a novel milk protein peptide.

BACKGROUND: Milk protein fractions and peptides have been shown to have bioactive properties. This preliminary study examined the potential mechanisms of action and clinical safety of novel milk protein peptide (MP). FINDINGS: A novel MP mixture inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor 2 (VEGFR2), and insulin receptor (IR) with IC50 of 9.85 µM, 7.7 µM, and 6.18 µM respectively. In vitro, this multi-kinase inhibitor causes apoptosis in HT-29 colon cancer cells, and in a C. elegans worm study, showed a weak but significant increase in lifespan. A six week double-blind, placebo-controlled study involving 73 healthy volunteers demonstrated that the MP mixture is safe to consume orally. All clinical blood markers remained within normal levels and no clinically significant side effects were reported. There was some evidence of improved insulin sensitivity, neutrophil-to-lymphocyte ratio (NLR), and quality of life assessment of role of physical function. CONCLUSIONS: These data in combination with the observed in vitro anti-cancer properties warrant further clinical studies to investigate this MP mixture as a potential clinical nutrition intervention for improving the quality of life and clinical outcomes in cancer patients. TRIAL REGISTRATION: NCT01412658.

Effects of Adherence to a Higher Protein Diet on Weight Loss, Markers of Health, and Functional Capacity in Older Women Participating in a Resistance-Based Exercise Program.

Resistance training and maintenance of a higher protein diet have been recommended to help older individuals maintain muscle mass. This study examined whether adherence to a higher protein diet while participating in a resistance-based exercise program promoted more favorable changes in body composition, markers of health, and/or functional capacity in older females in comparison to following a traditional higher carbohydrate diet or exercise training alone with no diet intervention. In total, 54 overweight and obese females (65.9 ± 4.7 years; 78.7 ± 11 kg, 30.5 ± 4.1 kg/m², 43.5 ± 3.6% fat) were randomly assigned to an exercise-only group (E), an exercise plus hypo-energetic higher carbohydrate (HC) diet, or a higher protein diet (HP) diet. Participants followed their respective diet plans and performed a supervised 30-min circuit-style resistance exercise program 3 d/wk. Participants were tested at 0, 10, and 14 weeks. Data were analyzed using univariate, multivariate, and repeated measures general linear model (GLM) statistics as well as one-way analysis of variance (ANOVA) of changes from baseline with [95% confidence intervals]. Results revealed that after 14 weeks, participants in the HP group experienced significantly greater reductions in weight (E -1.3 ± 2.3, [-2.4, -0.2]; HC -3.0 ± 3.1 [-4.5, -1.5]; HP -4.8 ± 3.2, [-6.4, -3.1]%, p = 0.003), fat mass (E -2.7 ± 3.8, [-4.6, -0.9]; HC -5.9 ± 4.2 [-8.0, -3.9]; HP -10.2 ± 5.8 [-13.2, ⁻7.2%], p < 0.001), and body fat percentage (E -2.0 ± 3.5 [-3.7, -0.3]; HC -4.3 ± 3.2 [-5.9, -2.8]; HP -6.3 ± 3.5 [-8.1, -4.5] %, p = 0.002) with no significant reductions in fat-free mass or resting energy expenditure over time or among groups. Significant differences were observed in leptin (E -1.8 ± 34 [-18, 14]; HC 43.8 ± 55 [CI 16, 71]; HP -26.5 ± 70 [-63, -9.6] ng/mL, p = 0.001) and adiponectin (E 43.1 ± 76.2 [6.3, 79.8]; HC -27.9 ± 33.4 [-44.5, -11.3]; HP 52.3 ± 79 [11.9, 92.8] µg/mL, p = 0.001). All groups experienced significant improvements in muscular strength, muscular endurance, aerobic capacity, markers of balance and functional capacity, and several markers of health. These findings indicate that a higher protein diet while participating in a resistance-based exercise program promoted more favorable changes in body composition compared to a higher carbohydrate diet in older females.

Impact of differing protein sources and a creatine containing nutritional formula after 12 weeks of resistance training.

OBJECTIVE: We evaluated whether colostrum (Col) or an isocaloric and isonitrogenous blend of whey and casein in addition to creatine (Cr) affects body composition, muscular strength and endurance, and anaerobic performance during resistance training. METHODS: Forty-nine resistance-trained subjects participated in a standardized 12-wk total body resistance training program. In a double-blind and randomized manner, subjects supplemented their diet with a protein control (Pro), Pro/Col, Pro/Cr, or Col/Cr. Supplements were isocaloric and isonitrogenous and provided 60 g/d of casein/whey (Pro) or Col as the protein source. At 0, 8, and 12 wk of supplementation, subjects were weighed, had body composition determined using dual-energy X-ray absorptiometry (DXA), performed one-repetition maximum (1RM) and 80% of 1RM tests on the bench press and leg press, and 30-s anaerobic sprint capacity tests. Data (mean +/- SD) were analyzed by repeated measures analysis of variance and reported as raw data in all tables and as changes from baseline for all figures for the Pro, Pro/Col, Pro/Cr, and Col/Cr groups, respectively. RESULTS: Resistance training increased 1RM strength, muscular endurance, and anaerobic sprint capacity equally in all groups. Significant main and interaction effects (P < 0.05) were found for body mass, DXA total scanned mass, and fat-free mass (FFM; lean plus bone), whereas no changes (P > 0.05) were noted for fat mass, percent fat, or bone content. Post hoc analysis showed that, compared with Pro, subjects ingesting Pro/Col, Pro/Cr, and Col/Cr showed greater gains in body mass and DXA total scanned mass. Subjects ingesting Pro/Cr and Col/Cr had greater increases in FFM during training in comparison with Pro/Col. CONCLUSION: In conjunction with 12 wk of resistance training, ingestion of Col or a blend of whey and casein protein with a vitamin/mineral supplement containing Cr resulted in greater improvements in FFM in comparison with Pro and Pro/Col.

Pharmacokinetics, safety, and effects on exercise performance of L-arginine alpha-ketoglutarate in trained adult men.

OBJECTIVE: We evaluated the pharmacokinetics, safety, and efficacy of l-arginine alpha-ketoglutarate (AAKG) in trained adult men. METHODS: Subjects participated in two studies that employed a randomized, double-blind, controlled design. In study 1, 10 healthy men (30-50 y old) fasted for 8 h and then ingested 4 g of time-released or non-timed-released AAKG. Blood samples were taken for 8 h after AAKG ingestion to assess the pharmacokinetic profile of L-arginine. After 1 wk the alternative supplement was ingested. In study 2, which was placebo controlled, 35 resistance-trained adult men (30-50 y old) were randomly assigned to ingest 4 g of AAKG (three times a day, i.e., 12 g daily, n = 20) or placebo (n = 15). Participants performed 4 d of periodized resistance training per week for 8 wk. At 0, 4, and 8 wk of supplementation the following tests were performed: clinical blood markers, one repetition maximum bench press, isokinetic quadriceps muscle endurance, anaerobic power, aerobic capacity, total body water, body composition, and psychometric parameters tests. Data were analyzed by repeated measures analysis of variance. RESULTS: In study 1, significant differences were observed in plasma arginine levels in subjects taking non-timed-release and timed-release AAKG. In study 2, significant differences were observed in the AAKG group (P < 0.05) for 1RM bench press, Wingate peak power, blood glucose, and plasma arginine. No significant differences were observed between groups in body composition, total body water, isokinetic quadriceps muscle endurance, or aerobic capacity. CONCLUSION: AAKG supplementation appeared to be safe and well tolerated, and positively influenced 1RM bench press and Wingate peak power performance. AAKG did not influence body composition or aerobic capacity.

Women 1.5 Times More Likely to Leave STEM Pipeline after Calculus Compared to Men: Lack of Mathematical Confidence a Potential Culprit.

The substantial gender gap in the science, technology, engineering, and mathematics (STEM) workforce can be traced back to the underrepresentation of women at various milestones in the career pathway. Calculus is a necessary step in this pathway and has been shown to often dissuade people from pursuing STEM fields. We examine the characteristics of students who begin college interested in STEM and either persist or switch out of the calculus sequence after taking Calculus I, and hence either continue to pursue a STEM major or are dissuaded from STEM disciplines. The data come from a unique, national survey focused on mainstream college calculus. Our analyses show that, while controlling for academic preparedness, career intentions, and instruction, the odds of a woman being dissuaded from continuing in calculus is 1.5 times greater than that for a man. Furthermore, women report they do not understand the course material well enough to continue significantly more often than men. When comparing women and men with above-average mathematical abilities and preparedness, we find women start and end the term with significantly lower mathematical confidence than men. This suggests a lack of mathematical confidence, rather than a lack of mathematically ability, may be responsible for the high departure rate of women. While it would be ideal to increase interest and participation of women in STEM at all stages of their careers, our findings indicate that if women persisted in STEM at the same rate as men starting in Calculus I, the number of women entering the STEM workforce would increase by 75%.

The effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exercise.

BACKGROUND: Phosphatidylserine (PS) is a phospholipid found in cell membranes of most animals and plants. PS has been shown to reduce stress and increase performance in runners, cyclists and golfers. The purpose of this study was to investigate the effects of a PS containing formulation on cognitive function, mood and endocrine response before and after intense resistance exercise. METHODS: 18 lower body, resistance trained, college aged males ingested 14 days of supplement (IQPLUS Focus, providing 400 mg of soy-derived PS) and a Placebo (PL), in a randomized, double-blind, placebo controlled, cross-over manner. Following 14 days of supplementation, participants performed an acute bout of lower body resistance training. Mood (Profile of Mood States, POMS) and cognitive function (Serial Subtraction Test, SST) were measured prior to, 5 minutes after, and 60 minutes after exercise. Venous blood samples were collected prior to, and 5, 15, 25, 40 and 60 minutes after exercise. Blood samples were analyzed for plasma cortisol and testosterone. Data were analyzed using repeated measures ANOVA. RESULTS: PS supplementation significantly reduced the time needed for a correct calculation on the SST by 20% (reduced by 1.27 s per calculation; PL: 6.4 s, PS: 5.13 s; p = 0.001), and reduced the total amount of errors by 39% (PL: 1.28 + .69, PS: .78 + .27, p = 0.53), and increased the amount of correct calculations by 13% (PL: 22.1 + 2.24, PS: 24.9 + 1.52, p = 0.07) prior to or in response to exercise compared to PL. Following exercise, there was no difference in SST scores between PS and PL. There were no significant changes in regards to mood or endocrine response to exercise as a result of PS supplementation. CONCLUSION: PS supplementation significantly increased cognitive function prior to exercise. Improved cognitive function could benefit athletes and non-athletes alike. PS did not appear to affect mood or endocrine response prior to or following resistance exercise.

A structured diet and exercise program promotes favorable changes in weight loss, body composition, and weight maintenance.

BACKGROUND: A number of diet and exercise programs purport to help promote and maintain weight loss. However, few studies have compared the efficacy of different methods. OBJECTIVE: To determine whether adherence to a meal-replacement-based diet program (MRP) with encouragement to increase physical activity is as effective as following a more structured meal-plan-based diet and supervised exercise program (SDE) in sedentary obese women. DESIGN: Randomized comparative effectiveness trial. PARTICIPANTS/SETTING: From July 2007 to October 2008, 90 obese and apparently healthy women completed a 10-week university-based weight loss trial while 77 women from this cohort also completed a 24-week weight maintenance phase. INTERVENTION: Participants were matched and randomized to participate in an MRP or SDE program. MAIN OUTCOME MEASURES: Weight loss, health, and fitness-related data were assessed at 0 and 10 weeks on all subjects as well as at 14, 22, and 34 weeks on participants who completed the weight maintenance phase. STATISTICAL ANALYSES PERFORMED: Data were analyzed by multivariate analysis of variance for repeated measures. RESULTS: During the 10-week weight loss phase, moderate and vigorous physical activity levels were significantly higher in the SDE group with no differences observed between groups in daily energy intake. The SDE group lost more weight (-3.1 ± 3.7 vs -1.6 ± 2.5 kg; P = 0.03); fat mass (-2.3 ± 3.5 vs -0.9 ± 1.6 kg; P = 0.02); centimeters from the hips (-4.6 ± 7 vs -0.2 ± 6 cm; P = 0.002) and waist (-2.9 ± 6 vs -0.6 ± 5 cm; P = 0.05); and, experienced a greater increase in peak aerobic capacity than participants in the MRP group. During the 24-week maintenance phase, participants in the SDE group maintained greater moderate and vigorous physical activity levels, weight loss, fat loss, and saw greater improvement in maximal aerobic capacity and strength. CONCLUSIONS: In sedentary and obese women, an SDE-based program appears to be more efficacious in promoting and maintaining weight loss and improvements in markers of health and fitness compared to an MRP type program with encouragement to increase physical activity.

Effects of arachidonic acid supplementation on training adaptations in resistance-trained males.

BACKGROUND: To determine the impact of AA supplementation during resistance training on body composition, training adaptations, and markers of muscle hypertrophy in resistance-trained males. METHODS: In a randomized and double blind manner, 31 resistance-trained male subjects (22.1 +/- 5.0 years, 180 +/- 0.1 cm, 86.1 +/- 13.0 kg, 18.1 +/- 6.4% body fat) ingested either a placebo (PLA: 1 g.day-1 corn oil, n = 16) or AA (AA: 1 g.day-1 AA, n = 15) while participating in a standardized 4 day.week-1 resistance training regimen. Fasting blood samples, body composition, bench press one-repetition maximum (1RM), leg press 1RM and Wingate anaerobic capacity sprint tests were completed after 0, 25, and 50 days of supplementation. Percutaneous muscle biopsies were taken from the vastus lateralis on days 0 and 50. RESULTS: Wingate relative peak power was significantly greater after 50 days of supplementation while the inflammatory cytokine IL-6 was significantly lower after 25 days of supplementation in the AA group. PGE2 levels tended to be greater in the AA group. However, no statistically significant differences were observed between groups in body composition, strength, anabolic and catabolic hormones, or markers of muscle hypertrophy (i.e. total protein content or MHC type I, IIa, and IIx protein content) and other intramuscular markers (i.e. FP and EP3 receptor density or MHC type I, IIa, and IIx mRNA expression). CONCLUSION: AA supplementation during resistance-training may enhance anaerobic capacity and lessen the inflammatory response to training. However, AA supplementation did not promote statistically greater gains in strength, muscle mass, or influence markers of muscle hypertrophy.

Effects of methoxyisoflavone, ecdysterone, and sulfo-polysaccharide supplementation on training adaptations in resistance-trained males.

PURPOSE: Methoxyisoflavone (M), 20-hydroxyecdysone (E), and sulfo-polysaccharide (CSP3) have been marketed to athletes as dietary supplements that can increase strength and muscle mass during resistance-training. However, little is known about their potential ergogenic value. The purpose of this study was to determine whether these supplements affect training adaptations and/or markers of muscle anabolism/catabolism in resistance-trained athletes. METHODS: Forty-five resistance-trained males (20.5 +/- 3 yrs; 179 +/- 7 cm, 84 +/- 16 kg, 17.3 +/- 9% body fat) were matched according to FFM and randomly assigned to ingest in a double blind manner supplements containing either a placebo (P); 800 mg/day of M; 200 mg of E; or, 1,000 mg/day of CSP3 for 8-weeks during training. At 0, 4, and 8-weeks, subjects donated fasting blood samples and completed comprehensive muscular strength, muscular endurance, anaerobic capacity, and body composition analysis. Data were analyzed by repeated measures ANOVA. RESULTS: No significant differences (p > 0.05) were observed in training adaptations among groups in the variables FFM, percent body fat, bench press 1 RM, leg press 1 RM or sprint peak power. Anabolic/catabolic analysis revealed no significant differences among groups in active testosterone (AT), free testosterone (FT), cortisol, the AT to cortisol ratio, urea nitrogen, creatinine, the blood urea nitrogen to creatinine ratio. In addition, no significant differences were seen from pre to post supplementation and/or training in AT, FT, or cortisol. CONCLUSION: Results indicate that M, E, and CSP3 supplementation do not affect body composition or training adaptations nor do they influence the anabolic/catabolic hormone status or general markers of catabolism in resistance-trained males.

Effects of coleus forskohlii supplementation on body composition and hematological profiles in mildly overweight women.

PURPOSE: This study investigated the effects of Coleus Forskohlii (CF) on body composition, and determined the safety and efficacy of supplementation. METHODS: In a double blind and randomized manner, 23 females supplemented their diet with ForsLeantrade mark (250 mg of 10% CF extract, (n = 7) or a placebo [P] (n = 12) two times per day for 12-wks. Body composition (DEXA), body weight, and psychometric instruments were obtained at 0, 4, 8 & 12 weeks of supplementation. Fasting blood samples and dietary records (4-d) were obtained at 0 and 12-wks. Side effects were recorded on a weekly basis. Data were analyzed by repeated measures ANOVA and are presented as mean changes from baseline for the CF and placebo groups, respectively. RESULTS: No significant differences were observed in caloric or macronutrient intake. CF tended to mitigate gains in body mass (-0.7 +/- 1.8, 1.0 +/- 2.5 kg, p = 0.10) and scanned mass (-0.2 +/- 1.3, 1.7 +/- 2.9 kg, p = 0.08) with no significant differences in fat mass (-0.2 +/- 0.7, 1.1 +/- 2.3 kg, p = 0.16), fat free mass (-0.1 +/- 1.3, 0.6 +/- 1.2 kg, p = 0.21), or body fat (-0.2 +/- 1.0, 0.4 +/- 1.4%, p = 0.40). Subjects in the CF group tended to report less fatigue (p = 0.07), hunger (p = 0.02), and fullness (p = 0.04). No clinically significant interactions were seen in metabolic markers, blood lipids, muscle and liver enzymes, electrolytes, red cells, white cells, hormones (insulin, TSH, T3, and T4), heart rate, blood pressure, or weekly reports of side effects. CONCLUSION: Results suggest that CF does not appear to promote weight loss but may help mitigate weight gain in overweight females with apparently no clinically significant side effects.