The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia.

OBJECTIVES: Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men. PARTICIPANTS: Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10). INTERVENTION: The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session. RESULTS: Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C. CONCLUSION: An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

Alignment of diet prescription to genotype does not promote greater weight loss success in women with obesity participating in an exercise and weight loss program.

OBJECTIVE: Genetics contribute to variability in individual response to weight-loss interventions. The objective of this study was to determine the efficacy of a commercially available exercise and weight-loss program and whether alignment of diet to genotype related to lipid metabolism promotes greater success. DESIGN: Sedentary women with obesity (n = 63) had genotype (FABP2rs1799883, PPARG2rs1801282, ADRB3rs4994C3, ADRB2rs1042713, rs1042714) determined using a direct-to-consumer genetic screening kit purported to promote greater weight-loss success through dietary recommendations based on these genes. Participants were randomly assigned to follow a moderate carbohydrate (MC) or lower carbohydrate (LC) hypo-energetic diet that aligned (A) or did not align (NA) with genotype for 24 weeks while participating in a resistance training and walking program. Data were analysed by general linear model repeated measures adjusted for baseline variables and are presented as mean (95% confidence interval) changes from baseline. RESULTS: Participants in the LC group experienced greater improvements (p = 0.051, ηp 2 = 0.025) in per cent changes in body composition (weight: MC -3.32 [-1.4, -5.2], LC -5.82 [-4.1, -7.6]; fat mass: MC -7.25 [-3.2, -11.2], LC -10.93 [-7.3, -14.5]; fat-free mass: MC -0.32 [1.4, -2.0], LC -1.48 [0.7, -3.0]; and body fat percentage: MC -4.19 [-1.6, -6.8], LC -5.60 [-3.3, -7.9] %). No significant differences were observed between genotype groups (weight: A -5.00 [-3.3, -6.7], NA -4.14 [-2.2, -6.1]; fat mass: A -10.15 [-7.0, -13.6], NA -8.02 [-4.0, -12.0]; fat-free mass: A -1.23 [0.3, -2.8], NA -0.56 [1.12, -2.3]; and body fat: A -5.28 [-3.0, -7.6], NA -4.51 [-1.9, -7.1] %). CONCLUSIONS: Adherence to this exercise and weight-loss program promoted improvements in body composition and health outcomes. While individuals following the LC diet experienced greater benefits, alignment of these diets to this genetic profile did not promote greater health outcomes.

Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (P<0.001) T2 of GR (95%), ST (65%), BFSh (51%) and BFLh (14%). After the Nordic hamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (P<0.001). Russian belt and conic-pulley exercise produced subtle (P<0.02) T2 increases of ST (9 and 6%, respectively) and BFLh (7 and 6%, respectively). Russian belt increased T2 of SM (7%). Among exercises examined, flywheel leg curl showed the most substantial hamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors.

Potential clinical applications of multi-functional milk proteins and peptides in cancer management.

The progression of cancer involves multiple changes that alter intracellular signaling to promote cell proliferation. Subsequent remodeling of the tumor microenvironment enhances metastasis by manipulating the immune system. Research in the past decade has shown that milk proteins and peptides are often multi-functional, exerting activities such as anti-microbial, immunomodulatory, cancer cell apoptosis, anti-metastasis, and antioxidant effects. Several milk-derived biologics, such as HAMLET (human α-lactalbumin made lethal to tumor cells) and the human recombinant form of lactoferrin, already demonstrated promising results in clinical trials. Lactoferricin peptide analogs are in early clinical development as antimicrobial agents and cancer immunotherapies. In addition, milk proteins and peptides are well tolerated and many exhibit oral bioavailability; thus they may complement standard therapies to boost overall success in cancer treatments. Lactoferrin, colostrum, and specific milk-derived peptide fractions are currently being developed as clinical nutrition for cancer prevention and chemotherapy protection. This review highlights the potential applications of milk proteins and peptides as pharmaceutical drug candidates and clinical nutrition in the overall management of cancer.

Effects of oral D-ribose supplementation on anaerobic capacity and selected metabolic markers in healthy males.

Oral D-ribose supplementation has been reported to increase adenine nucleotide synthesis and exercise capacity in certain clinical populations. Theoretically, increasing adenine nucleotide availability may enhance high intensity exercise capacity. This study evaluated the potential ergogenic value of D-ribose supplementation on repetitive high-intensity exercise capacity in 19 trained males. Subjects were familiarized to the testing protocol and performed two practice-testing trials before pre-supplementation testing. Each test involved warming up for 5 min on a cycle ergometer and then performing two 30-s Wingate anaerobic sprint tests on a computerized cycle ergometer separated by 3 min of rest recovery. In the pre- and post-supplementation trials, blood samples were obtained at rest, immediately following the first and second sprints, and following 5 min of recovery from exercise. Subjects were then matched according to body mass and anaerobic capacity and assigned to ingest, in a randomized and double blind manner, capsules containing either 5 g of a dextrose placebo (P) or D-ribose (R) twice daily (10 g/d) for 5 d. Subjects then performed post-supplementation tests on the 6th day. Data were analyzed by ANOVA for repeated measures. Results revealed a significant interaction (p =.04) in total work output. Post hoc analysis revealed that work significantly declined (-18 +/- 51 J) during the second post-supplementation sprint in the P group while being maintained in the R group (-0.0 +/- 31 J). No significant interactions were observed in peak power, average power, torque, fatigue index, lactate, ammonia, glucose, or uric acid. Results indicate that oral ribose supplementation (10 g/d for 5 d) does not affect anaerobic exercise capacity or metabolic markers in trained subjects as evaluated in this study.

Effects of calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation during resistance-training on markers of catabolism, body composition and strength.

Calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation has been reported to reduce muscle catabolism and promote gains in fat-free mass and strength in subjects initiating training. However, whether HMB supplementation promotes these adaptations in trained athletes is less clear. This study examined the effects of HMB (as the calcium salt) supplementation during resistance training (6.9+/-0.7 hr x wk(-1)) on markers of catabolism, body composition and strength in experienced resistance-trained males. In a double-blind and randomized manner, 40 experienced resistance-trained athletes were matched and assigned to supplement their diet for 28 d with a fortified carbohydrate/protein powder containing either 0, 3 or 6 g x d(-1) of calcium HMB. Fasting venous blood and urine samples, dual energy X-ray absorptiometer-determined body composition, and isotonic bench press and leg press one repetition maximums (1 RM) were determined prior to and following 28 d of supplementation. HMB supplementation resulted in significant increases in serum and urinary HMB concentrations. However, no statistically significant differences were observed in general markers of whole body anabolic/catabolic status, muscle and liver enzyme efflux, fat/bone-free mass, fat mass, percent body fat, or 1 RM strength. Results indicate that 28 d of HMB supplementation (3 to 6 g x d(-1)) during resistance-training does not reduce catabolism or affect training-induced changes in body composition and strength in experienced resistance-trained males.

Dietary supplements and the promotion of muscle growth with resistance exercise.

Nutritional strategies of overfeeding, ingesting carbohydrate/protein before and after exercise, and dietary supplementation of various nutrients [e.g. protein, glutamine, branched-chain amino acid, creatine, leucine, beta-hydroxy beta-methyl-butyrate (beta-HMB), chromium, vanadyl sulfate, boron, prasterone (dehydroepiandrosterone [DHEA]) and androstenedione] have been purported to promote gains in fat-free mass during resistance training. Most studies indicate that chromium, vanadyl sulfate and boron supplementation do not affect muscle growth. However, there is evidence that ingesting carbohydrate/protein prior to exercise may reduce catabolism during exercise and that ingesting carbohydrate/protein following resistance-exercise may promote a more anabolic hormonal profile. Furthermore, glutamine, creatine, leucine, and calcium beta-HMB may affect protein synthesis. Creatine and calcium beta-HMB supplementation during resistance training have been reported to increase fat-free mass in athletic and nonathletic populations. Prasterone supplementation has been reported to increase testosterone and fat-free mass in nontrained populations. However, results are equivocal, studies have yet to be conducted on athletes, and prasterone is considered a banned substance by some athletic organisations. This paper discusses rationale and effectiveness of these nutritional strategies in promoting lean tissue accretion during resistance training.

Effects of creatine supplementation on body composition, strength, and sprint performance.

PURPOSE: To determine the effects of 28 d of creatine supplementation during training on body composition, strength, sprint performance, and hematological profiles. METHODS: In a double-blind and randomized manner, 25 NCAA division IA football players were matched-paired and assigned to supplement their diet for 28 d during resistance/agility training (8 h x wk[-1]) with a Phosphagen HP (Experimental and Applied Sciences, Golden, CO) placebo (P) containing 99 g x d(-1) of glucose, 3 g x d(-1) of taurine, 1.1 g x d(-1) of disodium phosphate, and 1.2 g x d(-1) of potassium phosphate (P) or Phosphagen HP containing the P with 15.75 g x d(-1) of HPCE pure creatine monohydrate (HP). Before and after supplementation, fasting blood samples were obtained; total body weight, total body water, and body composition were determined; subjects performed a maximal repetition test on the isotonic bench press, squat, and power clean; and subjects performed a cycle ergometer sprint test (12 x 6-s sprints with 30-s rest recovery). RESULTS: Hematological parameters remained within normal clinical limits for active individuals with no side effects reported. Total body weight significantly increased (P < 0.05) in the HP group (P 0.85 +/- 2.2; HP 2.42 +/- 1.4 kg) while no differences were observed in the percentage of total body water. DEXA scanned body mass (P 0.77 +/- 1.8; HP 2.22 +/- 1.5 kg) and fat/bone-free mass (P 1.33 +/- 1.1; HP 2.43 +/- 1.4 kg) were significantly increased in the HP group. Gains in bench press lifting volume (P -5 +/- 134; HP 225 +/- 246 kg), the sum of bench press, squat, and power clean lifting volume (P 1,105 +/- 429; HP 1,558 +/- 645 kg), and total work performed during the first five 6-s sprints was significantly greater in the HP group. CONCLUSION: The addition of creatine to the glucose/taurine/electrolyte supplement promoted greater gains in fat/bone-free mass, isotonic lifting volume, and sprint performance during intense resistance/agility training.

Effects of ingesting supplements designed to promote lean tissue accretion on body composition during resistance training.

This study examined the effects of ingesting nutritional supplements designed to promote lean tissue accretion on body composition alterations during resistance training. Twenty-eight resistance-trained males blindly supplemented their diets with maltodextrin (M), Gainers Fuel 1000 (GF), or Phosphagain (P). No significant differences were observed in absolute or relative total body water among groups. Energy intake and body weight significantly increased in all groups combined throughout the study with no group or interaction differences observed. Dual energy x-ray absorptiometry-determined body mass significantly increased in each group throughout the study with significantly greater gains observed in the GF and P groups. Lean tissue mass (excluding bone) gain was significantly greater in the P group, while fat mass and percent body fat were significantly increased in the GF group. Results indicate that total body weight significantly increased in each group and that P supplementation resulted in significantly greater gains in lean tissue mass during resistance training.

Effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and performance.

The purpose of this study was to determine the effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and markers of anaerobic and aerobic performance. Seven members of the U.S. National Field Hockey Team were matched to 7 team counterparts (N = 14). One group was blindly administered a carbohydrate drink containing 1 g.kg-1 of carbohydrate four times daily, while the remaining group blindly ingested a flavored placebo during 7 days of intense training. Subjects underwent pre- and posttraining aerobic and anaerobic assessments, recorded daily diet intake, and were administered the Profile of Mood States (POMS) psychological inventory prior to and following each practice. Results revealed that the carbohydrate-supplemented group had a greater (p < .05) total energy intake, carbohydrate intake, and change (pre vs. post) in time to maximal exhaustion following training while reporting less postpractice psychological fatigue. However, no significant differences were observed in remaining psychological, physiological, or performance-related variables.

Amino acid supplementation and exercise performance. Analysis of the proposed ergogenic value.

Increasing the relative amount of protein in the diet of athletes has been suggested to optimise anabolic processes and improve both physiological responses to training and performance. While energy balance studies generally support the concept that athletes may require additional protein in their diets in comparison with the Recommended Dietary Allowances (RDA), most sport nutritionists contend that as long as athletes maintain energy balance and ingest 15% of their total caloric intake in the form of protein, additional supplementation of protein is not necessary. Recently, amino acids have become a popular nutritional supplement marketed to athletes. In strength athletes, amino acid supplementation has been proposed to increase the availability of essential amino acids, enhance anabolic processes promoting tissue accretion, and accelerate the rate of recovery during training. In endurance athletes, amino acid supplementation has been proposed to improve physiological and psychological responses during endurance exercise and training. There appears to be little scientific evidence to support the hypothesis that amino acid supplementation may enhance the physiological responses to strength training when athletes consume dietary protein within the recommended guidelines. Results of the effects of amino acid supplementation on the physiological and psychological responses to endurance exercise are preliminary. However, the findings suggest that amino acid supplementation with carbohydrate before, during and after exercise may alter the ratio of free tryptophan to branch-chained amino acids. Further research is required before definitive conclusions can be drawn regarding the proposed ergogenic value of amino acid supplementation.

Effects of phosphate loading on metabolic and myocardial responses to maximal and endurance exercise.

Six trained male cyclists and triathletes participated in a double blind study to determine the effects of phosphate loading on maximal and endurance exercise performance. Subjects ingested either 1 gm of tribasic sodium phosphate or a glucose placebo four times daily for 3 days prior to performing either an incremental maximal cycling test or a simulated 40-km time trial on a computerized race simulator. They continued the supplementation protocol for an additional day and then performed the remaining maximal or performance exercise test. Subjects observed a 17-day washout period between testing sessions and repeated the experiment with the alternate supplement regimen in identical fashion. Metabolic data were collected at 15-sec intervals while venous blood samples and 2D-echocardiographic data were collected during each stage of exercise during the maximal exercise test and at 8-km intervals during the 40-km time trial. Results indicate that phosphate loading attenuated anaerobic threshold, increased myocardial ejection fraction and fractional shortening, increased maximal oxidative capacity, and enhanced endurance performance in competitive cyclists and triathletes.

Physiological considerations of ultraendurance performance.

The physiological effects of endurance exercise have been a primary area of research in exercise science for many years. This research has led not only to a greater understanding of human physiology but also the limits of human performance. This is especially true regarding the effects of endurance exercise on energy metabolism and nutrition. However, as science has attempted to understand the physiological and nutritional demands of endurance exercise lasting 1 to 3 hours, an increasing number of athletes have begun participating in ultraendurance events lasting 4 to 24 hours. Consequently some research groups are now investigating the physiological responses to ultraendurance training and performance. This paper reviews the literature on ultraendurance performance and discusses nutritional factors that may affect bioenergetic, thermoregulatory, endocrinological, and hematological responses to ultraendurance performance.

Effect of inosine supplementation on 3-mile treadmill run performance and VO2 peak.

The purpose of this study was to investigate the ergogenic effect of oral inosine (IN) supplementation (6,000 mg.d-1 for 2 d) upon 3-mile run time (3MTIME) and VO2 peak. Nine highly trained endurance runners participated in a double-blind, placebo (PL), crossover study. Each subject undertook an IN or PL trial, consisting of three exercise tests: a submaximal warm-up run (SUBRUN), a competitive 3-mile treadmill run (3MRUN), and a maximal treadmill run (MAXRUN) to determine VO2 peak and time to exhaustion (MAXTIME). Additional measurements during the 3MRUN and MAXRUN included oxygen uptake (VO2), ventilation (VE), respiratory exchange ratio (R), and ratings of perceived exertion (RPE); blood samples were also taken prior (PRERUN) to the SUBRUN test and following the SUBRUN, 3MRUN, and MAXRUN tests in order to assess glucose, pyruvate, lactate, phosphorus, 2,3-DPG, hemoglobin, and uric acid. Analyses of the data revealed no significant effect of oral IN supplementation either upon 3MTIME (IN = 18.31 +/- 1.21; PL = 18.33 +/- 1.15 min) or VO2 peak (IN = 58.6 +/- 5.1; PL = 60.7 +/- 4.5 ml O2.kg-1.min-1) or upon other dependent variables. MAXTIME was significantly longer during the PL trial (P less than 0.05), suggestive of a possible impairment effect of oral IN supplementation. Based upon our data, we conclude that IN is not an effective ergogenic aid to enhance athletic performance of an aerobic nature.

Effects of phosphate loading on oxygen uptake, ventilatory anaerobic threshold, and run performance.

Seven male competitive runners (VO2max 73.9 +/- 6.3 ml.kg-1.min-1) participated in a two-session, placebo, double-blind study to determine the effects of phosphate loading on oxygen uptake, ventilatory anaerobic threshold, and 5-mile run performance. Subjects ingested 1000 mg of tribasic sodium phosphate or a placebo four times daily for 6 d. A maximal running stress test or a 5-mile performance run was performed randomly on either the 3rd or the 6th d. Test sessions were separated by a 2-wk washout period and repeated with alternating phosphate and placebo regimens. Venous blood samples were collected prior to and following each max and run session. Results revealed that placebo resting serum phosphate levels were mildly elevated and that phosphate loading significantly increased resting and post-exercise serum phosphate values. Resting and post-exercise 2,3-diphosphoglycerate values were decreased while hemoglobin values were elevated with phosphate ingestion. Phosphate loading significantly increased maximal oxygen uptake from 4.77 +/- 0.29 to 5.18 +/- 0.25 l.min-1 and ventilatory anaerobic threshold from 3.74 +/- 0.28 to 4.18 +/- 0.14 l.min-1. Five-mile run times were nonsignificantly different between placebo and phosphate sessions. However, mean performance run oxygen uptake was significantly lower (3.87 +/- 0.3 to 3.80 +/- 0.3 l.min-1) with phosphate ingestion. Data demonstrate that maximal and run performance were influenced by elevations in serum phosphate eliciting an increased maximal oxygen uptake, ventilatory anaerobic threshold, and variable effects on 5-mile run performance. These adaptations occurred without observable increases in red cell 2,3-diphosphoglycerate.

Cardiovascular and thermal responses of triathlon performance.

Triathletes typically train each triathlon event separately. Therefore, to determine the cardiovascular and thermal differences between training and triathlon performance, nine male triathletes performed a simulated 75-min (40 km) control bike and a 40-min (10 km) control run at 70% of maximal oxygen uptake. Control data were compared to data derived from a simulated triathlon (0.8-km swim, 75-min bike, and 40-min run). Results demonstrated that prior swimming significantly decreased (P less than 0.05) triathlon cycling work output (191 +/- 4.2 to 159 +/- 7.6 W) producing mean differences (P less than 0.05) in oxygen uptake (3.18 +/- 0.1 to 3.01 +/- 0.11.min-1), ventilation (84.7 +/- 4 to 80.4 +/- 4.21.min-1), stroke volume (128 +/- 7.1 to 118 +/- 3.5 ml.min-1), cardiac output (20.7 +/- 1.2 to 18.9 +/- 0.8 l.min-1), mean arterial pressure (105 +/- 3.8 to 96 +/- 7.9 mm Hg) and rectal temperature (38.2 +/- 0.2 to 38.4 +/- 0.3 degrees C). Triathlon running, while performing identical control work output, elicited significant increases (P less than 0.05) in oxygen uptake (3.41 +/- 0.1 to 3.85 +/- 0.1 l.min-1), ventilation (91.3 +/- 3.3 to 104.2 +/- 2.8 l.min-1), heart rate (161 +/- 3.1 to 174 +/- 3.6 beats.min-1), arteriovenous oxygen difference (15.3 +/- 0.2 to 17.2 +/- 0.3 ml.100 ml-1) and rectal temperature (38.3 +/- 0.2 and 39.2 +/- 0.3 degrees C) with significantly lower (P less than 0.05) stroke volume (138 +/- 2.4 to 129 +/- 3.6 ml.min-1) and mean arterial pressure (102 +/- 11.2 to 89 +/- 5.5 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)