Acute Physiological Responses to an Intensity-And Time-Under-Tension-Equated Single- vs. Multiple-Set Resistance Training Bout in Trained Men.

Cintineo, HP, Freidenreich, DJ, Blaine, CM, Cardaci, TD, Pellegrino, JK, and Arent, SM. Acute physiological responses to an intensity-and time under-under-tension-equated single- vs. multiple-set resistance training bout in trained men. J Strength Cond Res 32(12): 3310-3318, 2018-Regardless of the setting, proper manipulation of resistance training program design variables is pivotal in eliciting the desired physiological adaptations. Furthermore, how these variables, especially volume and intensity, work together to affect training outcomes is a major topic of investigation. The purpose of this study was to compare the acute biochemical, physiological, and hormonal responses of a single-set accentuated eccentric high-intensity training (HIT) protocol to a traditional 3-set protocol to better understand the acute effects of volume. Resistance-trained male college students (N = 19; age = 21.11 ± 2.5 years; height = 174.33 ± 6.83 cm; body mass = 76.72 ± 10.24 kg; %BF = 15.53 ± 6.35%) participated in this study and were randomly assigned to either the 1-set HIT protocol (HIT) or the 3-set traditional (3ST) protocol. Heart rate (HR), blood lactate, salivary testosterone, and salivary cortisol levels were measured before, during, and at multiple time points after the exercise bout. Results showed no differences in average HR or testosterone at any time point between the 2 groups. However, the 3ST group exhibited higher values of peak HR, blood lactate during exercise, and cortisol during and 30 minutes after exercise than the HIT group. This indicated that the 3ST protocol induced greater metabolic stress and disrupted the homeostatic balance to a greater magnitude than the HIT protocol despite similar time under tension. These results show that even when training to momentary muscular failure, volume seems to be a key driver of the training stimulus.

Triglyceride recrystallized phytosterols in fat-free milk improve lipoprotein profiles more than unmodified free phytosterols in hypercholesterolemic men and women.

OBJECTIVE: Foods incorporating plant sterols (PS) consistently decrease serum low-density lipoprotein cholesterol (LDL-C), although results vary depending on the PS form and food matrix. The objective was to study the effect of a novel triglyceride-recrystallized phystosterol (TRP) incorporated into fat-free milk on markers of cardiovascular risk compared to unmodified free sterols alone in the same fat-free milk. METHODS: Hypercholesterolemic men and women (n = 13 males/7 females; 56 ± 10 years; body mass index 27.3 ± 5.9 kg/m(2)) participated in 3 sequential 4-week phases of 480 mL milk consumption. During phase 1 (control) all subjects consumed 2% milk containing no PS, followed by phase 2 with fat-free milk containing free PS (2 g/d fPS) and phase 3 with fat-free milk with TRP (2 g/d). After each phase, determinations of lipoprotein cholesterol distribution, particle concentration via nuclear magnetic resonance (NMR), apolipoproteins, inflammatory markers, and fat-soluble dietary antioxidants were made. RESULTS: Body mass, body composition, dietary energy and macronutrients, and physical activity were unaffected throughout the study. Compared to the control 2% milk, LDL-C was significantly (p < 0.05) decreased by fPS (-9.1%) and was further decreased by TRP (-15.4%); reductions with TRP were significantly greater. Total LDL particle concentration was decreased to a greater extent after TRP (-8.8%) than fPS (-4.8%; p < 0.05). Only TRP significantly decreased serum levels of apolipoprotein B (apoB; -6%), interleukin-8 (IL-8; -11%) and monocyte chemotactic protein-1 (MCP-1; -19%). Plasma α- and γ-tocopherols and carotenoids, normalized to cholesterol, remained unchanged throughout the study with the exception that ß-carotene was lowered by 18%. CONCLUSION: In summary, TRP in fat-free milk may provide cardiovascular benefits beyond that of fPS by inducing more substantial decreases in LDL cholesterol and particle concentration, associated with declines in markers of vascular inflammation.

Whey protein supplementation during resistance training augments lean body mass.

UNLABELLED: Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. OBJECTIVE: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22). METHODS: All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (~9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months. RESULTS: Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass⁻¹, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. CONCLUSIONS: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.

Immune responses to resistance exercise.

Resistance exercise induces changes in leukocyte redistribution, phenotypical surface expression and leukocyte functionality. Several factors have been shown to alter the temporal pattern and/or magnitude of response including manipulation of acute program variables, the aging process, and nutritional supplementation. Rest period length and load can modify the temporal pattern and/or magnitude of leukocytosis post exercise. Aging diminishes both the duration and magnitude of the post exercise leukocytosis and reduces leukocyte functionality. The few studies that assessed the effects of nutritional supplements (e.g., carbohydrate, whey protein, caffeine) peri-resistance exercise showed minimal effects on leukocyte responses. Sex differences exist in the timing and magnitude of leukocyte infiltration into skeletal muscle. The immune response to resistance exercise is only a small part of the recovery paradigm. A better understanding of how acute program variables and other factors such as aging, sex and nutritional supplementation affect the immune response to resistance exercise is important in the context of improving recovery, performance and health.

Assessment of Sport Nutrition Knowledge, Dietary Practices, and Sources of Nutrition Information in NCAA Division III Collegiate Athletes.

Nutrition knowledge is a critical component of meeting sport nutrition guidelines. The present study aimed to evaluate the sport nutrition knowledge of National Collegiate Athletic Association (NCAA) Division III (DIII) athletes using a validated questionnaire, and to assess the dietary practices and sources of nutrition information in this population. A total of 331 student-athletes (n = 149 males, n = 181 females, n = 1 no sex indicated) completed the questionnaire. The mean score for total sport nutrition knowledge was 6.49 ± 8.9 (range -49 to 49) with a mean percent (%) correct score of 36.9 ± 19.1%. Athletes who had a previous college-level nutrition course (n = 62) had significantly higher (p < 0.05) total sport nutrition, carbohydrate, and hydration knowledge compared to those who did not (n = 268). Individual sport athletes (n = 90) scored significantly higher (p < 0.05) on hydration and micronutrients knowledge than team sport athletes (n = 237), while females scored higher than males for hydration knowledge (p < 0.05). The majority of athletes reported sensible dietary habits, such as not frequently skipping meals and eating carbohydrate and protein foods peri-workout. Athletes also reported their primary sources of nutrition information, the top three sources being social media, coaches, and athletic trainers, despite most frequently rating registered dietitians/nutritionists as "extremely knowledgeable". Despite low sport nutrition knowledge, NCAA DIII collegiate athletes practiced seemingly prudent dietary habits but lacked exposure to high-quality sources of nutrition information.

Acute ingestion of a novel whey-derived peptide improves vascular endothelial responses in healthy individuals: a randomized, placebo controlled trial.

BACKGROUND: Whey protein is a potential source of bioactive peptides. Based on findings from in vitro experiments indicating a novel whey derived peptide (NOP-47) increased endothelial nitric oxide synthesis, we tested its effects on vascular function in humans. METHODS: A randomized, placebo-controlled, crossover study design was used. Healthy men (n = 10) and women (n = 10) (25 +/- 5 y, BMI = 24.3 +/- 2.3 kg/m2) participated in two vascular testing days each preceded by 2 wk of supplementation with a single dose of 5 g/day of a novel whey-derived peptide (NOP-47) or placebo. There was a 2 wk washout period between trials. After 2 wk of supplementation, vascular function in the forearm and circulating oxidative stress and inflammatory related biomarkers were measured serially for 2 h after ingestion of 5 g of NOP-47 or placebo. Macrovascular and microvascular function were assessed using brachial artery flow mediated dilation (FMD) and venous occlusion strain gauge plethysmography. RESULTS: Baseline peak FMD was not different for Placebo (7.7%) and NOP-47 (7.8%). Placebo had no effect on FMD at 30, 60, and 90 min post-ingestion (7.5%, 7.2%, and 7.6%, respectively) whereas NOP-47 significantly improved FMD responses at these respective postprandial time points compared to baseline (8.9%, 9.9%, and 9.0%; P < 0.0001 for time x trial interaction). Baseline reactive hyperemia forearm blood flow was not different for placebo (27.2 +/- 7.2%/min) and NOP-47 (27.3 +/- 7.6%/min). Hyperemia blood flow measured 120 min post-ingestion (27.2 +/- 7.8%/min) was unaffected by placebo whereas NOP-47 significantly increased hyperemia compared to baseline (29.9 +/- 7.8%/min; P = 0.008 for time x trial interaction). Plasma myeloperoxidase was increased transiently by both NOP-47 and placebo, but there were no changes in markers inflammation. Plasma total nitrites/nitrates significantly decreased over the 2 hr post-ingestion period and were lower at 120 min after placebo (-25%) compared to NOP-47 (-18%). CONCLUSION: These findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function.

Metabolic characteristics of keto-adapted ultra-endurance runners.

BACKGROUND: Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. METHODS: Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO2max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n=10, %carbohydrate:protein:fat=59:14:25) diet, and the other a low-carbohydrate (LC; n=10, 10:19:70) diet for an average of 20 months (range 9 to 36 months). RESULTS: Peak fat oxidation was 2.3-fold higher in the LC group (1.54±0.18 vs 0.67±0.14 g/min; P=0.000) and it occurred at a higher percentage of VO2max (70.3±6.3 vs 54.9±7.8%; P=0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21±0.02 vs 0.76±0.11 g/min; P=0.000) corresponding to a greater relative contribution of fat (88±2 vs 56±8%; P=0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (-64% from pre-exercise) and 120 min of recovery (-36% from pre-exercise). CONCLUSION: Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar.

Effects of step-wise increases in dietary carbohydrate on circulating saturated Fatty acids and palmitoleic Acid in adults with metabolic syndrome.

Recent meta-analyses have found no association between heart disease and dietary saturated fat; however, higher proportions of plasma saturated fatty acids (SFA) predict greater risk for developing type-2 diabetes and heart disease. These observations suggest a disconnect between dietary saturated fat and plasma SFA, but few controlled feeding studies have specifically examined how varying saturated fat intake across a broad range affects circulating SFA levels. Sixteen adults with metabolic syndrome (age 44.9±9.9 yr, BMI 37.9±6.3 kg/m2) were fed six 3-wk diets that progressively increased carbohydrate (from 47 to 346 g/day) with concomitant decreases in total and saturated fat. Despite a distinct increase in saturated fat intake from baseline to the low-carbohydrate diet (46 to 84 g/day), and then a gradual decrease in saturated fat to 32 g/day at the highest carbohydrate phase, there were no significant changes in the proportion of total SFA in any plasma lipid fractions. Whereas plasma saturated fat remained relatively stable, the proportion of palmitoleic acid in plasma triglyceride and cholesteryl ester was significantly and uniformly reduced as carbohydrate intake decreased, and then gradually increased as dietary carbohydrate was re-introduced. The results show that dietary and plasma saturated fat are not related, and that increasing dietary carbohydrate across a range of intakes promotes incremental increases in plasma palmitoleic acid, a biomarker consistently associated with adverse health outcomes.