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Concept: Strength training

398

BACKGROUND: Consumption of moderate amounts of animal-derived protein has been shown to differently influence skeletal muscle hypertrophy during resistance training when compared with nitrogenous and isoenergetic amounts of plant-based protein administered in small to moderate doses. Therefore, the purpose of the study was to determine if the post-exercise consumption of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to equally dosed whey protein isolate if given in large, isocaloric doses. METHODS: 24 college-aged, resistance trained males were recruited for this study. Subjects were randomly and equally divided into two groups, either consuming 48 g of rice or whey protein isolate (isocaloric and isonitrogenous) on training days. Subjects trained 3 days per week for 8 weeks as a part of a daily undulating periodized resistance-training program. The rice and whey protein supplements were consumed immediately following exercise. Ratings of perceived recovery, soreness, and readiness to train were recorded prior to and following the first training session. Ultrasonography determined muscle thickness, dual emission x-ray absorptiometry determined body composition, and bench press and leg press for upper and lower body strength were recorded during weeks 0, 4, and 8. An ANOVA model was used to measure group, time, and group by time interactions. If any main effects were observed, a Tukey post-hoc was employed to locate where differences occurred. RESULTS: No detectable differences were present in psychometric scores of perceived recovery, soreness, or readiness to train (p > 0.05). Significant time effects were observed in which lean body mass, muscle mass, strength and power all increased and fat mass decreased; however, no condition by time interactions were observed (p > 0.05). CONCLUSION: Both whey and rice protein isolate administration post resistance exercise improved indices of body composition and exercise performance; however, there were no differences between the two groups.

Concepts: Whey protein, Myosin, Muscular system, Strength training, Weight training, Exercise physiology, Muscle hypertrophy, Whey

254

The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and >=44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general, protein supplementation pre- and post-workout increases physical performance, training session recovery, lean body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts. Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy and strength, a resistance weight- training program of at least 10–12 weeks with compound movements for both upper and lower body exercises should be followed.

Concepts: Protein, Amino acid, Glucose, Muscle, Physical exercise, Strength training, Exercise physiology, Bodybuilding

240

Aerobic exercise such as running enhances adult hippocampal neurogenesis (AHN) in rodents. Little is known about the effects of high-intensity interval training (HIT) or of purely anaerobic resistance training on AHN. Here, compared to a sedentary lifestyle, we report a very modest effect of HIT and no effect of resistance training on AHN in adult male rats. We find most AHN in rats that were selectively bred for an innately high response to aerobic exercise that also run voluntarily and - increase maximum running capacity. Our results confirm that sustained aerobic exercise is key in improving AHN.

Concepts: Obesity, Exercise, Overweight, Cycling, Strength training, Weight training, Exercise physiology, Running

219

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the use of beta-hydroxy-beta-methylbutyrate (HMB) as a nutritional supplement. The ISSN has concluded the following. 1. HMB can be used to enhance recovery by attenuating exercise induced skeletal muscle damage in trained and untrained populations. 2. If consuming HMB, an athlete will benefit from consuming the supplement in close proximity to their workout. 3. HMB appears to be most effective when consumed for 2 weeks prior to an exercise bout. 4. Thirty-eight mg.kg.BM-1 daily of HMB has been demonstrated to enhance skeletal muscle hypertrophy, strength, and power in untrained and trained populations when the appropriate exercise prescription is utilized. 5. Currently, two forms of HMB have been used: Calcium HMB (HMB-Ca) and a free acid form of HMB (HMB-FA). HMB-FA may increase plasma absorption and retention of HMB to a greater extent than HMB-CA. However, research with HMB-FA is in its infancy, and there is not enough research to support whether one form is superior. 6. HMB has been demonstrated to increase LBM and functionality in elderly, sedentary populations. 7. HMB ingestion in conjunction with a structured exercise program may result in greater declines in fat mass (FM). 8. HMB’s mechanisms of action include an inhibition and increase of proteolysis and protein synthesis, respectively. 9. Chronic consumption of HMB is safe in both young and old populations.

Concepts: Protein, Metabolism, Nutrition, Obesity, Muscular system, Strength training, Exercise physiology, Muscle hypertrophy

213

Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly).

Concepts: Time, Adenosine triphosphate, Obesity, Physical exercise, Exercise, Strength training, Creatine, Creatine supplements

202

BACKGROUND: The benefits of exercise are well established but one major barrier for many is time. It has been proposed that short period resistance training (RT) could play a role in weight control by increasing resting energy expenditure (REE) but the effects of different kinds of RT has not been widely reported. METHODS: We tested the acute effects of high-intensity interval resistance training (HIRT) vs. traditional resistance training (TT) on REE and respiratory ratio (RR) at 22 hours post-exercise. In two separate sessions, seventeen trained males carried out HIRT and TT protocols. The HIRT technique consists of: 6 repetitions, 20 seconds rest, 2/3 repetitions, 20 secs rest, 2/3 repetitions with 2[prime]30[prime][prime] rest between sets, three exercises for a total of 7 sets. TT consisted of eight exercises of 4 sets of 8–12 repetitions with one/two minutes rest with a total amount of 32 sets. We measured basal REE and RR (TT0 and HIRT0) and 22 hours after the training session (TT22 and HIRT22). RESULTS: HIRT showed a greater significant increase (p < 0.001) in REE at 22 hours compared to TT (HIRT22 2362 +/- 118 Kcal/d vs TT22 1999 +/- 88 Kcal/d). RR at HIRT22 was significantly lower (0.798 +/- 0.010) compared to both HIRT0 (0.827 +/- 0.006) and TT22 (0.822 +/- 0.008). CONCLUSIONS: Our data suggest that shorter HIRT sessions may increase REE after exercise to a greater extent than TT and may reduce RR hence improving fat oxidation. The shorter exercise time commitment may help to reduce one major barrier to exercise.

Concepts: Physical exercise, Exercise, Training, Strength training, Weight training, Trigraph, Gh, Order theory

181

Mild cognitive impairment (MCI) represents a critical window to intervene against dementia. Exercise training is a promising intervention strategy, but the efficiency (i.e., relationship of costs and consequences) of such types of training remains unknown. Thus, we estimated the incremental cost-effectiveness of resistance training or aerobic training compared with balance and tone exercises in terms of changes in executive cognitive function among senior women with probable MCI.

Concepts: Costs, Exercise, Thought, Cycling, Strength training, Weight training, Resistance training, Exercise physiology

169

OBJECTIVE: To evaluate effects of a multifactorial fall prevention program on fall incidence and physical function in community-dwelling older people. DESIGN: Multi-center randomized controlled clinical trial SETTING: Three medical centers and adjacent community health centers in Taiwan. PARTICIPANTS: Community-dwelling elderly who had fallen in the previous year or with risk of fall INTERVENTIONS: After baseline assessment, eligible subjects were randomly allocated into the intervention group (IG) or control group (CG) stratified by Physiological Profile Assessment (PPA) fall-risk level. IG received a 3-month multifactorial intervention program including 8-week exercise training, health education, home hazards evaluation/ modification, along with medication review and ophthalmology/other specialty consult. CG got health education brochures, referrals and recommendations without direct exercise intervention. MAIN OUTCOME MEASURES: Primary outcome was fall incidence within 1-year. Secondary outcomes were PPA battery (overall fall-risk index, vision, muscular strength, reaction time, balance and proprioception), timed up-and-go (TUG), Taiwanese-International Physical Activity Questionnaire, EuroQoL-5D, Geriatric Depression Scale (GDS), and Fall Efficacy Scale at 3 month after randomization. RESULTS: There were 616 participants with 76±7 years, including low risk 25.6%, moderate risk 25.6% and marked risk 48.7%. The cumulative 1-year fall incidence was 25.2% in IG and 27.6% in CG (HR=0.90, 95% CI 0.66-1.23). IG improved more favorably than CG on overall PPA fall-risk index, reaction time, postural sway with eyes open, TUG, and GDS, especially for those with marked fall-risk. CONCLUSIONS: The multifaceted fall prevention program with exercise intervention improved functional performance at 3-months for community-dwelling elders with risk of fall, but did not reduce falls over 1-year follow-up. Fall incidence might have been decreased simultaneously in both groups by heightened awareness engendered during assessments, education, referrals, and recommendations.

Concepts: Epidemiology, Clinical trial, Randomized controlled trial, Physical exercise, Old age, Strength training, Randomness, Geriatrics

168

Both aerobic (AER) and resistance (RES) training, if maintained over a period of several months, reduce HbA1c levels in type 2 diabetes subjects. However, it is still unknown whether the short-term effects of these types of exercise on blood glucose are similar. Our objective was to assess whether there may be a difference in acute blood glucose changes after a single bout of AER or RES exercise.

Concepts: Insulin, Diabetes mellitus type 2, Diabetes mellitus, Obesity, Diabetes, Blood sugar, Difference, Strength training

164

/st>Evidence is limited for the effectiveness of interventions for survivors of critical illness after hospital discharge. We explored the effect of an 8-week hospital-based exercise-training programme on physical fitness and quality-of-life.

Concepts: Clinical trial, Effectiveness, Exercise, Strength training