Nutritional Recommendations for Physique Athletes.

The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and female physique athletes in the contest preparation and recovery period. As optimal protein intake is largely related to one's skeletal muscle mass, current evidence supports a range of 1.8-2.7 g/kg. Furthermore, as a benefit from having adequate carbohydrate to fuel performance and activity, low-end fat intake during contest preparation of 10-25% of calories allows for what calories remain in the "energy budget" to come from carbohydrate to mitigate the negative impact of energy restriction and weight loss on training performance. For nutrient timing, we recommend consuming four or five protein boluses per day with one consumed near training and one prior to sleep. During competition periods, slower rates of weight loss (≤0.5% of body mass per week) are preferable for attenuating the loss of fat-free mass with the use of intermittent energy restriction strategies, such as diet breaks and refeeds, being possibly beneficial. Additionally, physiological and psychological factors are covered, and potential best-practice guidelines are provided for disordered eating and body image concerns since physique athletes present with higher incidences of these issues, which may be potentially exacerbated by certain traditional physique practices. We also review common peaking practices, and the critical transition to the post-competition period.

Gut Microbiota and Cardiometabolic Risk Factors in Hemodialysis Patients: A Pilot Study.

The gut microbiota has been implicated in the pathogenesis and progression of kidney disease. However, little is known about the gut microbiota in hemodialysis (HD) patients. We assessed the gut microbiota and its relationship with clinical variables in ten HD patients. We found that the Firmicutes-to-Bacteroidetes ratio was positively associated with traditional risk factors for cardiovascular disease. Furthermore, Faecalibacterium was positively associated with carbohydrate intake and negatively associated with arterial stiffness. Finally, endotoxemia was inversely associated with butyrate producers. Future studies should assess if targeting the gut microbiota result in a lower burden for cardiovascular disease in HD patients.

Efficacy of beta-hydroxy-beta-methylbutyrate supplementation in maintenance hemodialysis patients.

INTRODUCTION: Maintenance hemodialysis (MHD) patients suffer from a number of co-morbidities including declines in muscle mass and physical function. Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite of the amino acid leucine that has been shown to improve lean mass and physical function in elderly and clinical populations, but had not been studied in MHD patients. The purpose of this study was to investigate the efficacy of HMB in this population. METHODS: We performed a double-blind, placebo-controlled, randomized trial to assess the effects of daily HMB supplementation on co-morbidities in MHD patients. MHD patients were recruited and assigned to either daily supplementation with HMB (n = 16) or placebo (n = 17) for 6 months. Measurements of body composition, bone density, strength, physical function, fall risk, quality of life, and blood parameters were measured at baseline and 6 months. Blood was drawn at baseline, 3, and 6 months to measure compliance. FINDINGS: No significant effects of HMB on body composition, bone density, strength, physical function, fall risk, quality of life, or blood parameters were observed. On analysis of plasma HMB concentrations, 5 of 16 patients (31%) in the HMB group were found to be noncompliant at 3 or 6 months. Therefore, we performed a per-protocol analysis with compliant participants only and observed no significant differences in our outcomes of interest. DISCUSSION: These results do not support the efficacy of HMB to attenuate co-morbid conditions in MHD patients. Moreover, this highlights the need for future interventions targeted at reducing pill burden and improving pill compliance in this population.

Effects of Pomegranate Extract Supplementation on Cardiovascular Risk Factors and Physical Function in Hemodialysis Patients.

The purpose of this study was to evaluate the effects of oral supplementation with pomegranate extract on cardiovascular risk, physical function, oxidative stress, and inflammation in hemodialysis (HD) patients. Thirty-three HD subjects were randomized to the pomegranate (POM) or placebo (CON) group. Patients in POM ingested a 1000 mg capsule of a purified pomegranate polyphenol extract 7 days/week for 6 months. Individuals in CON ingested a noncaloric placebo capsule using the same protocol. Measurements were conducted at baseline and repeated 6 months following the start of the intervention. Brachial blood pressure (BP) was obtained using an automatic digital BP monitor. Cardiovascular risk was assessed using ultrasound and arterial tonometry. Blood samples were collected for the measurements of circulating markers of inflammation, oxidative stress, and antioxidant capacity. Muscle strength and physical function were assessed by isokinetic dynamometry, a validated shuttle walk test, and a battery of tests to assess functional fitness. Systolic blood pressure and diastolic blood pressure were reduced by 24 ± 13.7 and 10 ± 5.3 mmHg, respectively, in POM (P < .05). However, the BP differences in POM were no longer significant after controlling for baseline BP. The paraoxonase-1 activity increased by 26.6% (P < .05) in POM, compared to no significant change in CON. However, pomegranate supplementation had no effect on other markers of cardiovascular disease risk, inflammation and oxidative stress, or measures of physical function and muscle strength. While pomegranate extract supplementation may reduce BP and increase the antioxidant activity in HD patients, it does not improve other markers of cardiovascular risk, physical function, or muscle strength.

Rethinking the restriction on nutrition during hemodialysis treatment.

The annual mortality rate for patients undergoing maintenance hemodialysis (MHD) treatment in the United States is 20%, a rate higher than most other countries in the world. Poor nutrition status in MHD patients contributes to this adverse outcome as well as poor quality of life. Providing oral nutrition to MHD patients, especially during hemodialysis (HD) treatment has many potential benefits including improvements in nutrition status and attenuating HD-related muscle wasting. However, this practice is generally restricted in the United States presumably because of concerns that include worsening hemodynamic instability, reductions in treatment efficiency, and increased gastrointestinal symptoms. Despite widespread restrictions, few studies have adequately examined the effect of eating during HD on these outcomes, leaving many questions unanswered. This review outlines the current evidence regarding the effects of feeding during HD and provides potential future directions to outline the best practices in this controversial area.

Intradialytic protein supplementation reduces inflammation and improves physical function in maintenance hemodialysis patients.

OBJECTIVE: Protein malnutrition is both a cause and consequence of inflammation and related comorbidities for maintenance hemodialysis (MHD) patients. This study sought to determine if oral supplementation with soy or whey protein during dialysis treatment reduces inflammation and improves physical function and body composition in MHD patients. DESIGN: The design used in the study was randomized controlled trial, and the setting used was hemodialysis clinics in Champaign and Chicago, Illinois. SUBJECTS: Patients who received treatment ≥3 days/week, were ages ≥30 years did not have congestive heart failure or chronic obstructive pulmonary disease, and were receiving dialysis treatment for ≥3 months were eligible for inclusion. INTERVENTION: Patients were randomized to oral supplementation with a whey protein, soy protein, or placebo beverage. Patients (WHEY, n = 11; SOY, n = 12; CON, n = 15) consumed their assigned beverage before every dialysis session for 6 months. MAIN OUTCOME MEASURES: Body composition was measured by dual-energy x-ray absorptiometry, physical function by gait speed and shuttle walk test, and markers of inflammation (C-reactive protein and interleukin 6) using commercially available enzyme-linked immunosorbent assay kits before and after the 6-month intervention. Dietary intake was assessed by 24-hour dietary recalls. RESULTS: Six months of whey or soy supplementation significantly reduced predialysis interleukin 6 levels (P < .05 for both), whereas there was a trend for a reduction in C-reactive protein when both protein groups were combined (P = .062). Gait speed and shuttle walk test performance also significantly improved in the protein groups (P < .05 for both). No changes in body composition were observed. However, alkaline phosphatase, a marker of bone turnover, was significantly reduced in the protein groups. CONCLUSIONS: Intradialytic protein supplementation during a 6-month intervention reduced inflammation and improved physical function and represents an affordable intervention to improve the health of MHD patients.

Case study: Natural bodybuilding contest preparation.

The purpose of this study was to document the physiological changes that occur in a natural bodybuilder during prolonged contest preparation for a proqualifying contest. During the 26-week preparation, the athlete undertook a calorically restrictive diet with 2 days of elevated carbohydrate intake per week, increased cardiovascular (CV) training, and attempted to maintain resistance-training load. The athlete was weighed twice a week and body composition was measured monthly by DXA. At baseline and every 2 weeks following CV structure and function was measured using a combination of ultrasound, applanation tonometry, and heart rate variability (HRV). Cardiorespiratory performance was measured by VO(2)peak at baseline, 13 weeks, and 26 weeks. Body weight (88.6 to 73.3 Kg, R(2) = .99) and percent body fat (17.5 to 7.4%) were reduced during preparation. CV measurements including blood pressure (128/61 to 113/54 mmHg), brachial pulse wave velocity (7.9 to 5.8m/s), and measures of wave reflection all improved. Indexed cardiac output was reduced (2.5 to 1.8L/m(2)) primarily due to a reduction in resting heart rate (71 to 44 bpm), and despite an increase in ejection faction (57.9 to 63.9%). Assessment of HRV found a shift in the ratio of low to high frequency (209.2 to 30.9%). Absolute VO2 was minimally reduced despite weight loss resulting in an increase in relative VO2 (41.9 to 47.7 ml/Kg). In general, this prolonged contest preparation technique helped the athlete to improve body composition and resulted in positive CV changes, suggesting that this method of contest preparation appears to be effective in natural male bodybuilders.

Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation.

The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency. However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.

Postural control in hemodialysis patients.

The current investigation examined whether patients undergoing hemodialysis (HD) have reduced standing postural control performance during simultaneous cognitive task performance (i.e. dual task cost (DTC)) compared to age-gender matched controls. 19 persons undergoing HD and 19 age, gender, and body mass index (BMI) matched controls participated in the investigation. All participants performed 2 trials of quiet standing balance and 2 postural trials in which they performed a cognitive task. Postural control was indexed with various measures of the center of pressure (COP) trajectory. The change in postural control with a cognitive task (e.g. dual task cost DTC) was quantified as a change in the center of COP parameters of postural control from quiet standing to the cognitive condition. The primary observations were that (1) HD patients had significantly greater postural sway than age, gender, BMI matched controls (p's < 0.05); (2) HD patients had a greater DTC than the controls during quiet standing (p's < 0.05). The observations highlight that HD participants have poor postural control that is further exacerbated by a simultaneous performance of a cognitive task. It is possible that this impaired postural control places HD participants at elevated fall risk. Further study is necessary to determine contributing factors to an increased DTC in this population and whether targeted interventions such as exercise can reduce DTC.

Elderly persons with ICU-acquired weakness: the potential role for ß-hydroxy-ß-methylbutyrate (HMB) supplementation?

Intensive care unit (ICU)-acquired weakness is common and characterized by muscle loss, weakness, and paralysis. It is associated with poor short-term outcomes, including increased mortality, but the consequences of reduced long-term outcomes, including decreased physical function and quality of life, can be just as devastating. ICU-acquired weakness is particularly relevant to elderly patients who are increasingly consuming ICU resources and are at increased risk for ICU-acquired weakness and complications, including mortality. Elderly patients often enter critical illness with reduced muscle mass and function and are also at increased risk for accelerated disuse atrophy with acute illness. Increasingly, intensivists and researchers are focusing on strategies and therapies aimed at improving long-term neuromuscular function. ß-Hydroxy-ß-methylbutyrate (HMB), an ergogenic supplement, has shown efficacy in elderly patients and certain clinical populations in counteracting muscle loss. The present review discusses ICU-acquired weakness, as well as the unique physiology of muscle loss and skeletal muscle function in elderly patients, and then summarizes the evidence for HMB in elderly patients and in clinical populations. We subsequently postulate on the potential role and strategies in studying HMB in elderly ICU patients to improve muscle mass and function.

Effect of muscle strength on gait in hemodialysis patients with and without diabetes.

There is minimal data on the gait of hemodialysis (HD) patients with and without diabetes. This investigation examined spatiotemporal parameters of gait in HD patients with and without diabetes compared with age-matched, sex-matched, and BMI-matched controls. The effect of muscle weakness on gait in HD patients was also examined. Eighteen HD patients and 18 age-matched, sex-matched, and BMI-matched controls completed two walking trials along a 7.9 m long pressure sensitive pathway. The HD participants were divided into groups based on their diabetic status (eight patients without diabetes and 10 with diabetes). Spatiotemporal markers of gait, including variability metrics, were determined. Knee strength was quantified only in the HD groups. Overall HD patients had a worse gait compared with controls (P<0.01). Furthermore, HD patients with diabetes had an elevated gait variability compared with those without diabetes, even after controlling for muscle strength (P<0.05). Further research is warranted to explore whether increases in lower extremity strength lead to improvements in gait in this population.

International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB).

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.

Walking and talking in maintenance hemodialysis patients.

OBJECTIVES: To investigate whether there is a reduction in walking with the simultaneous performance of a cognitive task (ie, dual-task cost [DTC]) in persons undergoing hemodialysis (HD), and whether it is greater in persons undergoing HD compared with age-matched controls. DESIGN: Cohort. SETTING: University research laboratory. PARTICIPANTS: Persons undergoing HD (n=14; 5 women, 9 men; mean age ± SD, 50.0±11.8y) and age-matched controls (n=14; 4 women, 10 men; mean age ± SD, 48.5±10.1y) participated in the investigation. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Participants walked at a self-selected pace on an electronic pathway, which recorded spatiotemporal parameters of gait, in 4 separate trials and completed a cognitive task in the last 2 trials. The DTC was quantified as the change in spatiotemporal parameters of gait from baseline to the cognitive trials. RESULTS: The HD group had a greater decrease in walking function during the cognitive task, with DTC ranging from 6% to 14%. On average, walking velocity decreased to less than 1m/s in HD patients during the cognitive condition. Baseline walking velocity was found to be moderately correlated with the magnitude of DTC of cadence and step time (ρ=-.44 and .46; P values <.05). CONCLUSIONS: Persons undergoing HD have greater interference between walking and talking compared with controls. Difficulty walking while thinking has implications for everyday life and may be related to the risk of falls. Further work is necessary to determine other contributing factors to elevated DTC in HD patients, and whether DTC can be reduced with targeted interventions.

Efficacy of ß-hydroxy-ß-methylbutyrate supplementation in elderly and clinical populations.

Muscle loss is common during aging and chronic diseases, such as cancer and acquired immunodeficiency syndrome. Moreover, muscle loss has been correlated with decreased physical function, quality of life, and mortality in these populations. Therefore, interventions to counteract muscle loss in the elderly and clinical populations are needed. Recently, the efficacy of the leucine metabolite, ß-hydroxy-ß-methylbutyrate (HMB), to maintain muscle mass has been investigated in these populations. Many studies have found increases in lean mass and strength in the elderly and clinical populations when using HMB; however, not all studies have found beneficial effects of HMB supplementation. The present review summarizes published human studies investigating the efficacy of HMB supplementation in the elderly and clinical populations. In addition, the mechanisms by which HMB may exert its effects are summarized and future research directions are suggested.

Cardiovascular effects of consumption of black versus English walnuts.

English walnuts have been shown to decrease cardiovascular disease risk; however, black walnuts do not appear to have not been studied for their cardioprotective effects. The purpose of this study was to determine the effects of English versus black walnut consumption on blood lipids, body weight, fatty-acid composition of red blood cell (RBC) membranes, and endothelial function. Consumption of 30 g of English walnuts per day for 30 days, by 36 human participants, improved blood lipids; the effects of black walnuts were dependent on the participant's sex. Addition of either nut to the diet did not result in weight gain. The fatty-acid composition of RBC membranes was favorably affected by walnut consumption. RBC polyunsaturated fatty acids increased after consumption of either type of nut; however, eicosapentaenoic acid increased significantly more after English walnut consumption. Endothelial function of 6 unmedicated humans with hypercholesterolemia was maintained after consumption of English walnuts with a meal high in high saturated fats; however, consumption of black walnuts with the same meal did not maintain endothelial function. Overall, these results support the recommendation that consumption of 1 oz of English walnuts per day may decrease cardiovascular risk, but more research on black walnut consumption is necessary before an appropriate recommendation can be made.