Structural and Functional Properties of Lower Extremity Tendons in Men.

ABSTRACT: Comstock, BA, Flanagan, SD, Denegar, CR, Newton, RU, Häkkinen, K, Volek, JS, Maresh, CM, Kraemer, WJ. Structural and functional properties of lower extremity tendons in men. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to understand further patellar and Achilles tendon structure and function, body composition, and serum collagen turnover biomarkers in young men who performed heavy resistance training (RT, n = 13, age: 22.2 ± 1.4 years) compared with recreationally active men who were not resistance-trained (NR, n = 13, age: 22.8 ± 2.2 years). Tendon properties were measured at rest and during maximal voluntary isometric efforts using ultrasonography and dynamometry. Lean body mass (LBM) and bone mineral density (BMD) were assessed with dual X-ray absorptiometry. Serum collagen turnover markers were analyzed and related to tendon measures. Resistance-trained men had significantly (p ≤ 0.05) greater LBM and BMD compared with recreationally active men. Resistance-trained men also showed significantly greater patellar tendon (PT) stiffness (45%) and Young's modulus (36%), though the PT cross-sectional area (CSA) did not differ significantly between groups. Achilles tendon CSA was significantly larger in resistance-trained men. Still, other properties such as stiffness and modulus did not differ significantly between the groups. Serum collagen turnover markers showed no significant differences between groups and were not correlated to any tendon or bone biomarkers. The findings support that resistance-trained men have greater LBM and BMD. However now, it reveals that tendon adaptations differ, as not all measures were similarly affected in both tendons. The blood biomarkers did not show any obvious roles in explaining the differential changes in tendons. Heavy RT induces differential tendon changes potentially due to complex interactions of training variables.

The VirTra V-100 Is a Test-Retest Reliable Shooting Simulator for Measuring Accuracy/Precision, Decision-Making, and Reaction Time in Civilians, Police/SWAT, and Military Personnel.

ABSTRACT: Buga, A, Decker, DD, Robinson, BT, Crabtree, CD, Stoner, JT, Arce, LF, El-Shazly, X, Kackley, ML, Sapper, TN, Anders, JPV, Kraemer, WJ, and Volek, JS. The VirTra V-100 is a test-retest reliable shooting simulator for measuring accuracy/precision, decision-making, and reaction time in civilians, police/SWAT, and military personnel. J Strength Cond Res XX(X): 000-000, 2024-Law-enforcement agencies and the military have increasingly used virtual reality (VR) to augment job readiness. However, whether VR technology captures consistent data for shooting performance evaluation has never been explored. We enrolled 30 adults (24 M/6 F) to examine test-retest reliability of the VirTra shooting simulator. Approximately 30% of the sample had a tactical background (PD/SWAT and military). Trained research staff familiarized subjects with how to shoot the infrared-guided M4 rifle at digitally projected targets. Subjects then performed 3 identical experimental shooting sessions (consecutive or separated by 1-2 days) that assessed accuracy/precision, decision-making, and reaction time. Key metrics comprised projectile Cartesian position ( x , y ), score, time, and throughput (score or accuracy divided by time). Test-retest reliability was measured with intraclass correlation coefficients (ICC). After each visit, subjects completed a perceptual survey to self-evaluate their shooting performance and perceived VR realism. The simulator captured 21 ballistic variables with good to excellent test-retest agreement, producing a global ICC of 0.78. Notable metrics were the individual projectile distances to the center of the target (0.81), shot group radius (0.91), time-to-first decision (0.97), decision-making throughput (0.95), and target transition reaction time (0.91). Subjects had positive self-evaluations about their shooting performance, with "confidence" increasing from baseline to the end of the study ( p = 0.014). The VirTra V-100 virtual ballistic shooting simulator captures data with a high degree of test-retest reliability and is easy to familiarize regardless of starting expertise levels, making it appropriate for use as a method to objectively track progress or a tactical research testing tool.

Metabolic and ruck performance effects of a novel, light-weight, energy-dense ketogenic bar.

NEW FINDINGS: What is the central question of the study? Can a novel, energy-dense and lightweight ketogenic bar (1000 kcal) consumed 3 h before exercise modulate steady-state incline rucksack march ('ruck') performance compared to isocaloric carbohydrate bars in recreationally active, college-aged men? What is the main finding and its importance? Acute ingestion of either nutritional bar sustained ∼1 h of exhaustive rucking with a 30% of body weight rucksack. This proof-of-concept study is the first to demonstrate that carbohydrate bars and lipid bars are equally feasible for preserving ruck performance. Novel ketogenic nutrition bars may have military-relevant applications to lessen carry load without compromising exercise capacity. ABSTRACT: Rucksack marches ('rucks') are strenuous, military-relevant exercises that may benefit from pre-event fuelling. The purpose of this investigation was to explore whether acute ingestion of carbohydrate- or lipid-based nutritional bars before rucking can elicit unique advantages that augment exercise performance. Recreationally active and healthy males (n = 29) were randomized and counterbalanced to consume 1000 kcal derived from a novel, energy-dense (percentage energy from carbohydrate/fat/protein: 5/83/12) ketogenic bar (KB), or isocaloric high-carbohydrate bars (CB; 61/23/16) 3 h before a time-to-exhaustion (TTE) ruck. Conditions were separated by a 1-week washout. The rucksack weight was standardized to 30% of bodyweight. Steady-state treadmill pace was set at 3.2 km/h (0.89 m/s) and 14% grade. TTE was the primary outcome; respiratory exchange ratio (RER), capillary ketones (R-ß-hydroxybutyrate), glucose and lactate, plus subjective thirst/hunger were the secondary outcomes. Mean TTE was similar between conditions (KB: 55 ± 25 vs. CB: 54 ± 22 min; P = 0.687). The RER and substrate oxidation rates revealed greater fat and carbohydrate oxidation after the KB and CB, respectively (all P < 0.0001). Capillary R-ßHB increased modestly after the KB ingestion (P < 0.0001). Neither bar influenced glycaemia. Lactate increased during the ruck independent of the condition (P < 0.0001). Thirst/fullness perceptions changed independent of the nutritional bar consumed. A novel KB nutritional bar produced equivalent TTE ruck results to the isocaloric CBs. The KB's energy density relative to CB (6.6 vs. 3.8 kcal/g) may provide a lightweight (-42% weight), pre-event fuelling alternative that does not compromise ruck physical performance.

Continuous care intervention with carbohydrate restriction improves physical function of the knees among patients with type 2 diabetes: a non-randomized study.

BACKGROUND: In a previous study, we assessed a novel, remotely monitored carbohydrate restricted diet regimen including nutritional ketosis in patients with type 2 diabetes and reported significant improvements in weight, glycemic control, abdominal fat and inflammation from baseline to 2 years. Knee outcome measures were collected as a secondary outcome in the trial. This study aims to assess the effect of this intervention on knee functional scores and to identify if changes in weight, central abdominal fat (CAF), glycemic status and high sensitivity C-reactive protein (hsCRP) were associated with its improvement. METHODS: This prospective analysis included continuous care intervention (CCI, n = 173) and usual care (UC, n = 69) trial participants with type 2 diabetes that reported knee pain at baseline. Knee outcome measures included the Knee injury and Osteoarthritis Outcome Score (KOOS) pain, symptoms, activities of daily living (ADL), sports and recreation function, and knee-related quality of life subscales, and total KOOS score were assessed from baseline to 2 years. Missing data at each time point were replaced with multiple imputation under the assumption of missing at random. To assess if the primary analysis of the knee scores changed under plausible missing not at random assumptions, sensitivity analysis was also performed using pattern mixture models. In CCI, we also assessed factors associated with the improvement of knee scores. RESULTS: In the primary analysis, CCI participants demonstrated a statistically significant improvement in total KOOS and all KOOS individual subscale scores at 1 year and maintained through 2 years as opposed to UC patients who showed no significant changes from baseline to 2 years. The significant improvement in total KOOS and its individual subscale scores from baseline to 2 years remained relatively stable in CCI in the sensitivity analysis under different missing not at random scenarios confirming the robustness of the findings from the primary analysis. Approximately 46% of the CCI participants met the 10 points minimal clinically important change at 2 years. A reduction in CAF was associated with improvement in total KOOS and KOOS ADL, while a decrease in hsCRP was associated with improvement in KOOS symptoms scores. CONCLUSION: A very low carbohydrate intervention including nutritional ketosis resulted in significant improvements in knee pain and function among patients with T2D. The improvements in knee function were likely secondary to a reduction in central adiposity and inflammation. Future research on the applicability of this intervention in radiographically confirmed OA patients is important. TRIAL REGISTRATION: Clinical trial registration: NCT02519309 (10/08/2015).

Arousal/Stress Effects of "Overwatch" eSports Game Competition in Collegiate Gamers.

ABSTRACT: Kraemer, WJ, Caldwell, LK, Post, EM, Beeler, MK, Emerson, A, Volek, JS, Maresh, CM, Fogt, JS, Fogt, N, Häkkinen, K, Newton, RU, Lopez, P, Sanchez, BN, and Onate, JA. Arousal/stress effects of "Overwatch" eSports game competition in collegiate gamers. J Strength Cond Res 36(10): 2671-2675, 2022-To date, no physical response data are available for one of the most popular eSport games, Overwatch . The purpose of this investigation was to describe the stress signaling associated with competitive Overwatch play and to understand how acute hormonal responses may affect performance. Thirty-two male college-aged gamers (age: 21.3 ± 2.7 years; estimated time played per week: 18 ± 15 hours) completed the study. Subjects were randomly assigned to a 6-player team to compete in a tournament-style match. Salivary measures of cortisol and testosterone were collected immediately before (PRE) and after (POST) the first-round game, with the heart rate recorded continuously during the match. The mean characteristics were calculated for each variable and comparisons made by the skill level. Significance was defined as p ≤ 0.05. There were no differences in measures of salivary cortisol. A differential response pattern was observed by the skill level for testosterone. The low skill group displayed a significant increase in testosterone with game play (mean ± SD , testosterone PRE: 418.3 ± 89.5 pmol·L -1 , POST: 527.6 ± 132.4 pmol·L -1 , p < 0.001), whereas no change was observed in the high skill group. There were no differences in heart rate characteristics between skill groups. Overall, the average heart rate was 107.2 ± 17.8 bpm with an average max heart rate of 133.3 ± 19.1 bpm. This study provides unique physiological evidence that a sedentary Overwatch match modulates endocrine and cardiovascular responses, with the skill level emerging as a potential modulator.

Differences in brain structure and theta burst stimulation-induced plasticity implicate the corticomotor system in loss of function after musculoskeletal injury.

Traumatic musculoskeletal injury (MSI) may involve changes in corticomotor structure and function, but direct evidence is needed. To determine the corticomotor basis of MSI, we examined interactions among skeletomotor function, corticospinal excitability, corticomotor structure (cortical thickness and white matter microstructure), and intermittent theta burst stimulation (iTBS)-induced plasticity. Nine women with unilateral anterior cruciate ligament rupture (ACL) 3.2 ± 1.1 yr prior to the study and 11 matched controls (CON) completed an MRI session followed by an offline plasticity-probing protocol using a randomized, sham-controlled, double-blind, cross-over study design. iTBS was applied to the injured (ACL) or nondominant (CON) motor cortex leg representation (M1LEG) with plasticity assessed based on changes in skeletomotor function and corticospinal excitability compared with sham iTBS. The results showed persistent loss of function in the injured quadriceps, compensatory adaptations in the uninjured quadriceps and both hamstrings, and injury-specific increases in corticospinal excitability. Injury was associated with lateralized reductions in paracentral lobule thickness, greater centrality of nonleg corticomotor regions, and increased primary somatosensory cortex leg area inefficiency and eccentricity. Individual responses to iTBS were consistent with the principles of homeostatic metaplasticity; corresponded to injury-related differences in skeletomotor function, corticospinal excitability, and corticomotor structure; and suggested that corticomotor adaptations involve both hemispheres. Moreover, iTBS normalized skeletomotor function and corticospinal excitability in ACL. The results of this investigation directly confirm corticomotor involvement in chronic loss of function after traumatic MSI, emphasize the sensitivity of the corticomotor system to skeletomotor events and behaviors, and raise the possibility that brain-targeted therapies could improve recovery.NEW & NOTEWORTHY Traumatic musculoskeletal injuries may involve adaptive changes in the brain that contribute to loss of function. Our combination of neuroimaging and theta burst transcranial magnetic stimulation (iTBS) revealed distinct patterns of iTBS-induced plasticity that normalized differences in muscle and brain function evident years after unilateral knee ligament rupture. Individual responses to iTBS corresponded to injury-specific differences in brain structure and physiological activity, depended on skeletomotor deficit severity, and suggested that corticomotor adaptations involve both hemispheres.

Resistance Training and Milk-Substitution Enhance Body Composition and Bone Health in Adolescent Girls.

Background: Increased soft-drink consumption has contributed to poor calcium intake with 90% of adolescent girls consuming less than the RDA for calcium.Purpose/objectives: The purpose of this investigation was to determine the independent and additive effects of two interventions (milk and resistance training) on nutrient adequacy, body composition, and bone health in adolescent girls.Methods: The experimental design consisted of four experimental groups of adolescent girls 14-17 years of age: (1) Milk + resistance training [MRT]; n = 15; (2) Resistance training only [RT]; n = 15; (3) Milk only [M] n = 20; (4) Control [C] n = 16. A few significant differences were observed at baseline between the groups for subject characteristics. Testing was performed pre and post-12 week training period for all groups. Milk was provided (3, 8 oz servings) for both the MRT and the M groups. The MRT group and the RT groups performed a supervised periodized resistance training program consisting of supervised one-hour exercise sessions 3 d/wk (M, W, F) for 12 wk. Baseline dietary data was collected utilizing the NUT-P-FFQ and/or a 120 item FFQ developed by the Fred Hutchinson Cancer Research Center (Seattle, Washington). Body composition was measured in the morning after an overnight fast using dual-energy X-ray absorptiometry (DXA) with a total body scanner (ProdigyTM, Lunar Corporation, Madison, WI). A whole body scan for bone density and lumbar spine scans were performed on all subjects. Maximal strength of the upper and lower body was assessed via a one-repetition maximum (1-RM) squat and bench press exercise protocols. Significance was set at P ≤ 0.05.Results: Significant differences in nutrient intakes between groups generally reflected the nutrient composition of milk with greater intakes of protein and improved nutrient adequacy for several B vitamins, vitamin A, vitamin D, calcium, magnesium, phosphorus, potassium, and zinc. Mean calcium intake was 758 and 1581 mg/d, in the non-milk and milk groups, respectively, with 100% of girls in the milk groups consuming > RDA of 1300 mg/d. There were no effects of milk on body composition or muscle performance, but resistance training had a main effect and significantly increased body mass, lean body mass, muscle strength, and muscle endurance. There was a main effect of milk and resistance training on several measures of bone mineral density (BMD). Changes in whole body BMD in the M, RT, MRT, and CON were 0.45, 0.52, 1.32, and -0.19%, respectively (P < 0.01).Conclusions: Over the course of 12 weeks the effects of 1300 mg/d of calcium in the form of fluid milk combined with a heavy resistance training program resulted in the additive effects of greater nutrient adequacy and BMD in adolescent girls. While further studies are needed, combining increased milk consumption with resistance training appears to optimize bone health in adolescent girls.

Acute Effects of High-intensity Resistance Exercise on Cognitive Function.

The purpose of the present study was to examine the influence of an acute bout of high-intensity resistance exercise on measures of cognitive function. Ten men (Mean ± SD: age = 24.4 ± 3.2 yrs; body mass = 85.7 ± 11.8 kg; height = 1.78 ± 0.08 m; 1 repetition maximum (1RM) = 139.0 ± 24.1 kg) gave informed consent and performed a high-intensity 6 sets of 10 repetitions of barbell back squat exercise at 80% 1RM with 2 minutes rest between sets. The Automated Neuropsychological Assessment Metrics (ANAM) was completed to assess various cognitive domains during the familiarization period, immediately before, and immediately after the high-intensity resistance exercise bout. The repeated measures ANOVAs for throughput scores (r·m-1) demonstrated significant mean differences for the Mathematical Processing task (MTH; p < 0.001, η2p = 0.625) where post hoc pairwise comparisons demonstrated that the post-fatigue throughput (32.0 ± 8.8 r·m-1) was significantly greater than the pre-fatigue (23.8 ± 7.4 r·m-1, p = 0.003, d = 1.01) and the familiarization throughput (26.4 ± 5.3 r·m-1, p = 0.024, d = 0.77). The Coded Substitution-Delay task also demonstrated significant mean differences (CDD; p = 0.027, η2p = 0.394) with post hoc pairwise comparisons demonstrating that the post-fatigue throughput (49.3 ± 14.4 r·m-1) was significantly less than the pre-fatigue throughput (63.2 ± 9.6 r·m-1, p = 0.011, d = 1.14). The repeated measures ANOVAs for reaction time (ms) demonstrated significant mean differences for MTH (p < 0.001, η2p = 0.624) where post hoc pairwise comparisons demonstrated that the post-fatigue reaction time (1885.2 ± 582.8 ms) was significantly less than the pre-fatigue (2518.2 ± 884.8 ms, p = 0.005, d = 0.85) and familiarization (2253.7 ± 567.6 ms, p = 0.009, d = 0.64) reaction times. The Go/No-Go task demonstrated significant mean differences (GNG; p = 0.031, η2p = 0.320) with post hoc pairwise comparisons demonstrating that the post-fatigue (285.9 ± 16.3 ms) was significantly less than the pre-fatigue (298.5 ± 12.1 ms, p = 0.006, d = 0.88) reaction times. High-intensity resistance exercise may elicit domain-specific influences on cognitive function, characterized by the facilitation of simple cognitive tasks and impairments of complex cognitive tasks.

A ketogenic diet combined with exercise alters mitochondrial function in human skeletal muscle while improving metabolic health.

Animal data indicate that ketogenic diets are associated with improved mitochondrial function, but human data are lacking. We aimed to characterize skeletal muscle mitochondrial changes in response to a ketogenic diet combined with exercise training in healthy individuals. Twenty-nine physically active adults completed a 12-wk supervised exercise program after self-selection into a ketogenic diet (KD, n = 15) group or maintenance of their habitual mixed diet (MD, n = 14). Measures of metabolic health and muscle biopsies (vastus lateralis) were obtained before and after the intervention. Mitochondria were isolated from muscle and studied after exposure to carbohydrate (pyruvate), fat (palmitoyl-l-carnitine), and ketone (ß-hydroxybutyrate+acetoacetate) substrates. Compared with MD, the KD resulted in increased whole body resting fat oxidation (P < 0.001) and decreased fasting insulin (P = 0.019), insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR), P = 0.022], and visceral fat (P < 0.001). The KD altered mitochondrial function as evidenced by increases in mitochondrial respiratory control ratio (19%, P = 0.009), ATP production (36%, P = 0.028), and ATP/H2O2 (36%, P = 0.033) with the fat-based substrate. ATP production with the ketone-based substrate was four to eight times lower than with other substrates, indicating minimal oxidation. The KD resulted in a small decrease in muscle glycogen (14%, P = 0.035) and an increase in muscle triglyceride (81%, P = 0.006). These results expand our understanding of human adaptation to a ketogenic diet combined with exercise. In conjunction with weight loss, we observed altered skeletal muscle mitochondrial function and efficiency, an effect that may contribute to the therapeutic use of ketogenic diets in various clinical conditions, especially those associated with insulin resistance.

Impact of a 2-year trial of nutritional ketosis on indices of cardiovascular disease risk in patients with type 2 diabetes.

BACKGROUND: We have previously reported that in patients with type 2 diabetes (T2D) consumption of a very low carbohydrate diet capable of inducing nutritional ketosis over 2 years (continuous care intervention, CCI) resulted in improved body weight, glycemic control, and multiple risk factors for cardiovascular disease (CVD) with the exception of an increase in low density lipoprotein cholesterol (LDL-C). In the present study, we report the impact of this intervention on markers of risk for atherosclerotic cardiovascular disease (CVD), with a focus on lipoprotein subfraction particle concentrations as well as carotid-artery intima-media thickness (CIMT). METHODS: Analyses were performed in patients with T2D who completed 2 years of this study (CCI; n = 194; usual care (UC): n = 68). Lipoprotein subfraction particle concentrations were measured by ion mobility at baseline, 1, and 2 years and CIMT was measured at baseline and 2 years. Principal component analysis (PCA) was used to assess changes in independent clusters of lipoprotein particles. RESULTS: At 2 years, CCI resulted in a 23% decrease of small LDL IIIb and a 29% increase of large LDL I with no change in total LDL particle concentration or ApoB. The change in proportion of smaller and larger LDL was reflected by reversal of the small LDL subclass phenotype B in a high proportion of CCI participants (48.1%) and a shift in the principal component (PC) representing the atherogenic lipoprotein phenotype characteristic of T2D from a major to a secondary component of the total variance. The increase in LDL-C in the CCI group was mainly attributed to larger cholesterol-enriched LDL particles. CIMT showed no change in either the CCI or UC group. CONCLUSION: Consumption of a very low carbohydrate diet with nutritional ketosis for 2 years in patients with type 2 diabetes lowered levels of small LDL particles that are commonly increased in diabetic dyslipidemia and are a marker for heightened CVD risk. A corresponding increase in concentrations of larger LDL particles was responsible for higher levels of plasma LDL-C. The lack of increase in total LDL particles, ApoB, and in progression of CIMT, provide supporting evidence that this dietary intervention did not adversely affect risk of CVD.

A Pre-Workout Supplement of Ketone Salts, Caffeine, and Amino Acids Improves High-Intensity Exercise Performance in Keto-Naïve and Keto-Adapted Individuals.

Background: Acute ingestion of ketone supplements alters metabolism and potentially exercise performance. No studies to date have evaluated the impact of co-ingestion of ketone salts with caffeine and amino acids on high intensity exercise performance, and no data exists in Keto-Adapted individuals.Methods: We tested the performance and metabolic effects of a pre-workout supplement containing beta-hydroxybutyrate (BHB) salts, caffeine, and amino acids (KCA) in recreationally-active adults habitually consuming a mixed diet (Keto-Naïve; n = 12) or a ketogenic diet (Keto-Adapted; n = 12). In a randomized and balanced manner, subjects consumed either the KCA consisting of ∼7 g BHB (72% R-BHB and 28% S-BHB) with ∼100 mg of caffeine, and amino acids (leucine and taurine) or Water (control condition) 15 minutes prior to performing a staged cycle ergometer time to exhaustion test followed immediately by a 30 second Wingate test.Results: Circulating total BHB concentrations increased rapidly after KCA ingestion in KN (154 to 732 µM) and KA (848 to 1,973 µM) subjects and stayed elevated throughout recovery in both groups. Plasma S-BHB increased >20-fold 15 minutes after KCA ingestion in both groups and remained elevated throughout recovery. Compared to Water, KCA ingestion increased time to exhaustion 8.3% in Keto-Naïve and 9.8% in Keto-Adapted subjects (P < 0.001). There was no difference in power output during the Wingate test between trials. Peak lactate immediately after exercise was higher after KCA (∼14.9 vs 12.7 mM).Conclusion: These results indicate that pre-exercise ingestion of a moderate dose of R- and S-BHB salts combined with caffeine, leucine and taurine improves high-intensity exercise performance to a similar extent in both Keto-Adapted and Keto-Naïve individuals.

Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Men.

Wilson, JM, Lowery, RP, Roberts, MD, Sharp, MH, Joy, JM, Shields, KA, Partl, JM, Volek, JS, and D'Agostino, DP. Effects of ketogenic dieting on body composition, strength, power, and hormonal profiles in resistance training men. J Strength Cond Res 34(12): 3463-3474, 2020-This study investigated the impact of an isocaloric and isonitrogenous ketogenic diet (KD) versus a traditional western diet (WD) on changes in body composition, performance, blood lipids, and hormonal profiles in resistance-trained athletes. Twenty-five college-aged men were divided into a KD or traditional WD from weeks 1 to 10, with a reintroduction of carbohydrates from weeks 10 to 11, while participating in a resistance training program. Body composition, strength, power, and blood lipid profiles were determined at weeks 0, 10, and 11. A comprehensive metabolic panel and testosterone levels were also measured at weeks 0 and 11. Lean body mass (LBM) increased in both the KD and WD groups (2.4% and 4.4%, p < 0.01) at week 10. However, only the KD group showed an increase in LBM between weeks 10 and 11 (4.8%, p < 0.0001). Finally, fat mass decreased in both the KD (-2.2 ± 1.2 kg) and WD groups (-1.5 ± 1.6 kg). Strength and power increased to the same extent in the WD and KD conditions from weeks 1 to 11. No changes in any serum lipid measures occurred from weeks 1 to 10; however, a rapid reintroduction of carbohydrate from weeks 10 to 11 raised plasma triglyceride levels in the KD group. Total testosterone increased significantly from weeks 0 to 11 in the KD diet (118 ng·dl) as compared to the WD (-36 ng·dl) from pre to post while insulin did not change. The KD can be used in combination with resistance training to cause favorable changes in body composition, performance, and hormonal profiles in resistance-trained men.

Body Composition in Elite Strongman Competitors.

Kraemer, WJ, Caldwell, LK, Post, EM, DuPont, WH, Martini, ER, Ratamess, NA, Szivak, TK, Shurley, JP, Beeler, MK, Volek, JS, Maresh, CM, Todd, JS, Walrod, BJ, Hyde, PN, Fairman, C, and Best, TM. Body composition in elite strongman competitors. J Strength Cond Res 34(12): 3326-3330, 2020-The purpose of this descriptive investigation was to characterize a group of elite strongman competitors to document the body composition of this unique population of strength athletes. Data were collected from eligible competitors as part of a health screening program conducted over 5 consecutive years. Imaging was acquired using dual-energy x-ray absorptiometry (DXA), providing total body measures of fat mass, lean mass, and bone mineral content (BMC). Year to year, testing groups showed a homogenous grouping of anthropometric, body composition, and bone density metrics. Composite averages were calculated to provide an anthropometric profile of the elite strongman competitor (N = 18; mean ± SD): age, 33.0 ± 5.2 years; body height, 187.4 ± 7.1 cm; body mass, 152.9 ± 19.3 kg; body mass index, 43.5 ± 4.8 kg·m; fat mass, 30.9 ± 11.1 kg; lean mass, 118.0 ± 11.7 kg, body fat, 18.7 ± 6.2%, total BMC, 5.23 ± 0.41 kg, and bone mineral density, 1.78 ± 0.14 g·cm. These data demonstrate that elite strongman competitors are among the largest human male athletes, and in some cases, they are at the extreme limits reported for body size and structure. Elite strongman competitors undergo a high degree of mechanical stress, providing further insight into the potent role of physical training in mediating structural remodeling even into adulthood. Such data provide a glimpse into a unique group of competitive athletes pushing the limits not only of human performance but also of human physiology.

Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study.

BACKGROUND: Cardiovascular disease (CVD) is a leading cause of death among adults with type 2 diabetes mellitus (T2D). We recently reported that glycemic control in patients with T2D can be significantly improved through a continuous care intervention (CCI) including nutritional ketosis. The purpose of this study was to examine CVD risk factors in this cohort. METHODS: We investigated CVD risk factors in patients with T2D who participated in a 1 year open label, non-randomized, controlled study. The CCI group (n = 262) received treatment from a health coach and medical provider. A usual care (UC) group (n = 87) was independently recruited to track customary T2D progression. Circulating biomarkers of cholesterol metabolism and inflammation, blood pressure (BP), carotid intima media thickness (cIMT), multi-factorial risk scores and medication use were examined. A significance level of P < 0.0019 ensured two-tailed significance at the 5% level when Bonferroni adjusted for multiple comparisons. RESULTS: The CCI group consisted of 262 participants (baseline mean (SD): age 54 (8) year, BMI 40.4 (8.8) kg m-2). Intention-to-treat analysis (% change) revealed the following at 1-year: total LDL-particles (LDL-P) (- 4.9%, P = 0.02), small LDL-P (- 20.8%, P = 1.2 × 10-12), LDL-P size (+ 1.1%, P = 6.0 × 10-10), ApoB (- 1.6%, P = 0.37), ApoA1 (+ 9.8%, P < 10-16), ApoB/ApoA1 ratio (- 9.5%, P = 1.9 × 10-7), triglyceride/HDL-C ratio (- 29.1%, P < 10-16), large VLDL-P (- 38.9%, P = 4.2 × 10-15), and LDL-C (+ 9.9%, P = 4.9 × 10-5). Additional effects were reductions in blood pressure, high sensitivity C-reactive protein, and white blood cell count (all P < 1 × 10-7) while cIMT was unchanged. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk score decreased - 11.9% (P = 4.9 × 10-5). Antihypertensive medication use was discontinued in 11.4% of CCI participants (P = 5.3 × 10-5). The UC group of 87 participants [baseline mean (SD): age 52 (10) year, BMI 36.7 (7.2) kg m-2] showed no significant changes. After adjusting for baseline differences when comparing CCI and UC groups, significant improvements for the CCI group included small LDL-P, ApoA1, triglyceride/HDL-C ratio, HDL-C, hsCRP, and LP-IR score in addition to other biomarkers that were previously reported. The CCI group showed a greater rise in LDL-C. CONCLUSIONS: A continuous care treatment including nutritional ketosis in patients with T2D improved most biomarkers of CVD risk after 1 year. The increase in LDL-cholesterol appeared limited to the large LDL subfraction. LDL particle size increased, total LDL-P and ApoB were unchanged, and inflammation and blood pressure decreased. Trial registration Clinicaltrials.gov: NCT02519309. Registered 10 August 2015.

Co-ingestion of whole eggs or egg whites with glucose protects against postprandial hyperglycaemia-induced oxidative stress and dysregulated arginine metabolism in association with improved vascular endothelial function in prediabetic men.

Replacing a portion of a glucose challenge with whole eggs (EGG) or egg whites (WHITE) was shown to protect against glucose-induced impairments in vascular function. We hypothesised in the present study that previously observed vasoprotection following co-ingestion of EGG or WHITE with glucose was attributed to limiting postprandial hyperglycaemia-induced oxidative stress that improves NO∙ bioavailability. Prediabetic men completed a randomised, cross-over study in which they ingested isoenergetic meals containing 100 g glucose (GLU), or 75 g glucose with 1·5 EGG, seven WHITE or two egg yolks (YOLK). At 30 min intervals for 3 h, we assessed plasma NO∙ metabolites, the lipid peroxidation biomarker malondialdehyde, antioxidants, arginine and its methylated metabolites (asymmetric dimethylarginine and symmetric dimethylarginine), tetrahydrobiopterin redox status, vasoconstrictors and inflammatory markers. Compared with GLU, malondialdehyde was lower and NO∙ metabolites were greater in EGG and WHITE, but YOLK was not different from GLU. Malondialdehyde was inversely correlated with NO∙ metabolites and vascular function, whereas NO∙ metabolites were positively correlated with vascular function. Compared with GLU, arginine was greater, but asymmetric and symmetric dimethylarginine and angiotensin-II were lower in all egg-based meals. Antioxidants, tetrahydrobiopterin redox status and inflammatory markers did not differ among treatments. Thus, while each egg-based meal improved arginine metabolism, only EGG and WHITE limited lipid peroxidation. This suggests that vasoprotection mediated by EGG and WHITE likely occurs in an NO∙-dependent manner by improving arginine metabolism and attenuating oxidative stress that otherwise limit NO∙ biosynthesis and bioavailability to the vascular endothelium.

Replacing carbohydrate during a glucose challenge with the egg white portion or whole eggs protects against postprandial impairments in vascular endothelial function in prediabetic men by limiting increases in glycaemia and lipid peroxidation.

Eggs attenuate postprandial hyperglycaemia (PPH), which transiently impairs vascular endothelial function (VEF). We hypothesised that co-ingestion of a glucose challenge with egg-based meals would protect against glucose-induced impairments in VEF by attenuating PPH and oxidative stress. A randomised, cross-over study was conducted in prediabetic men (n 20) who ingested isoenegertic meals (1674 kJ (400 kcal)) containing 100 g glucose (GLU), or 75 g glucose with 1·5 whole eggs (EGG), seven egg whites (WHITE) or two egg yolks (YOLK). At 30 min intervals for 3 h, brachial artery flow-mediated dilation (FMD), plasma glucose, insulin, cholecystokinin (CCK), lipids (total, LDL- and HDL-cholesterol; TAG), F2-isoprostanes normalised to arachidonic acid (F2-IsoPs/AA), and methylglyoxal were assessed. In GLU, FMD decreased at 30-60 min and returned to baseline levels by 90 min. GLU-mediated decreases in FMD were attenuated at 30-60 min in EGG and WHITE. Compared with GLU, FMDAUC was higher in EGG and WHITE only. Relative to baseline, glucose increased at 30-120 min in GLU and YOLK but only at 30-90 min in EGG and WHITE. GlucoseAUC and insulinAUC were also lower in EGG and WHITE only. However, CCKAUC was higher in EGG and WHITE compared with GLU. Compared with GLU, F2-IsoPs/AAAUC was lower in EGG and WHITE but unaffected by YOLK. Postprandial lipids and methylglyoxal did not differ between treatments. Thus, replacing a portion of a glucose challenge with whole eggs or egg whites, but not yolks, limits postprandial impairments in VEF by attenuating increases in glycaemia and lipid peroxidation.

The Effects of a Korean Ginseng, GINST15, on Perceptual Effort, Psychomotor Performance, and Physical Performance in Men and Women.

The purpose of this double-blind, placebo-controlled investigation was to examine the effects of a Korean Ginseng (GINST15) on measures of perception and physical performance following an acute bout of resistance exercise. Ten women (age: 38.7 ± 7.8 years; height: 1.64 ± 0.05 m; body mass: 76.0 ± 11.6 kg) and nine men (age: 41.2. ± 9.7 years; height: 1.77 ± 0.05 m; body mass: 88.5 ± 5.0 kg) completed the investigation. Participants were randomized to a three-cycle testing scheme consisting of high dose ginseng (HIGH: 960 mg/day), low dose ginseng (LOW: 160 mg/day) and placebo (PBO: 0 mg/day). After 14 days of supplementation participants returned to the laboratory for an acute resistance exercise trial (5 sets of 12 repetitions of the leg press at 70% of one-repetition-maximum [1RM]). Ratings of perceived exertion (RPE) were assessed after each set. Muscle pain/soreness was assessed before exercise and 24 hours post exercise. Psychomotor performance and peak power were measured before exercise, immediately post exercise and 24 hours after exercise. Each treatment cycle was separated by a minimum one-week washout period. HIGH significantly reduced perceived exertion during exercise. HIGH and LOW significantly reduced change in muscle soreness at 24 hours post exercise. Analysis of peak power demonstrated the presence of responders (n = 13) and non-responders (n = 6). Responders showed a significant effect of HIGH GINST15 on maintenance of neuromuscular function. The appearance of responders and non-responders, could explain the mixed literature base on the ergogenic properties of ginseng.

Relationships between hydration biomarkers and total fluid intake in pregnant and lactating women.

INTRODUCTION: Previous research established significant relationships between total fluid intake (TFI) and urinary biomarkers of the hydration process in free-living males and females; however, the nature of this relationship is not known for pregnant (PREG) and lactating (LACT) women. PURPOSE: To determine the relationship between urinary and hematological hydration biomarkers with TFI in PREG and LACT. METHODS: Eighteen PREG/LACT (age: 31 ± 3 years, pre-pregnancy BMI: 24.26 ± 5.85 kg m-2) collected 24-h urine samples, recorded TFI, and provided a blood sample at 5 time points (15 ± 2, 26 ± 1, 37 ± 1 weeks gestation, 3 ± 1 and 9 ± 1 weeks postpartum during lactation); 18 pair-matched non-pregnant (NP), non-lactating (NL) women (age: 29 ± 4 years, BMI: 24.1 ± 3.7 kg m-2) provided samples at similar time intervals. Twenty-four-hour urine volume (U VOL), osmolality (U OSM), specific gravity (U SG), and color (U COL) were measured. Hematocrit, serum osmolality (S OSM), and serum total protein (S TP) were measured in blood. RESULTS: Significant relationships were present between TFI and urinary biomarkers in all women (P < 0.004); these relationships were not different between PREG and NP, and LACT and NL, except U VOL in PREG (P = 0.0017). No significant relationships between TFI and hematological biomarkers existed (P > 0.05). CONCLUSION: Urinary biomarkers of hydration, but not hematological biomarkers, have a strong relationship with TFI in PREG, LACT, NP, and NL women. These data suggest that urinary biomarkers of hydration reflect TFI during pregnancy and breast-feeding.

The presence of symptoms of testosterone deficiency in the exercise-hypogonadal male condition and the role of nutrition.

PURPOSE: High volumes of aerobic exercise have been associated with reduced testosterone (T), known as the exercise-hypogonadal male condition (EHMC). Although the presence of low T has been identified, few studies have assessed the presence of androgen-deficient symptoms. The purpose of this investigation is to assess men exhibiting EHMC and evaluate their hypothalamic-pituitary-gonadal axis, the presence of hypogonadal symptoms, and also investigate a possible contribution of inadequate nutrition to the condition. METHODS: A cross-sectional design compared 9 long-distance runners exhibiting EHMC to 8 non-active controls. Comparisons included serum T, luteinizing hormone (LH), follicle-stimulating hormone, and cortisol, the Aging Male Symptoms (AMS) questionnaire score, bone mineral density (BMD), and a food frequency questionnaire. RESULTS: Mean T was significantly reduced in the EHMC group (EHMC 9.2 nmol L-1 vs. CONT 16.2 nmol L-1). The EHMC group demonstrated significantly higher AMS scores (EHMC 27.1 ± 7.3 vs. CONT 19.7 ± 2.5). There were no differences in bone density, although 3 cases of osteopenia were noted for EHMC in the lumbar spine, 1 in the right femur, and 1 in the radius. Energy availability was significantly reduced in EHMC (EHMC 27.2 ± 12.7 vs. CONT 45.4 ± 18.2 kcal d FFM-1). CONCLUSIONS: Men exhibiting EHMC do appear to present with symptoms associated with androgen deficiency. For the most part, these symptoms are limited to those reported on the AMS questionnaire, although there are also some cases of clinically low BMD. It is possible that inadequate energy intake is contributing to this condition.