Dietary protein intake and renal function

Recent trends in weight loss diets have led to a substantial increase in protein intake by individuals. As a result, the safety of habitually consuming dietary protein in excess of recommended intakes has been questioned. In particular, there is concern that high protein intake may promote renal damage by chronically increasing glomerular pressure and hyperfiltration. There is, however, a serious question as to whether there is significant evidence to support this relationship in healthy individuals. In fact, some studies suggest that hyperfiltration, the purported mechanism for renal damage, is a normal adaptative mechanism that occurs in response to several physiological conditions. This paper reviews the available evidence that increased dietary protein intake is a health concern in terms of the potential to initiate or promote renal disease. While protein restriction may be appropriate for treatment of existing kidney disease, we find no significant evidence for a detrimental effect of high protein intakes on kidney function in healthy persons after centuries of a high protein Western diet

Mild Dehydration Led to Increased Difficulty Falling Asleep

Sleep is fundamental process that benefits health and overall quality of life which can be affected by various aspects of daily living such as dehydration. A study has yet to investigate the impacts of euhydration and mild dehydration on sleep. PURPOSE: The purpose of this study was to examine effects of euhydration, mild-dehydration, and ad libitum drinking on sleep. METHODS: Eighteen male participants (mean±SD; age, 23±4y; height, 175.8±5.7cm; weight, 80.1±9.7kg) reported to the laboratory with different hydration status for 4 consecutive mornings(Day 1, baseline; Day 2, euhydrated; Day 3, mild-dehydrated; Day 4, ad libitum drinking). Hydration status was monitored by first morning urine specific gravity (USG) and plasma osmolality. Sleepwas measured using the Karolinska sleep diary (KSD). RESULTS: USG (baseline, 1.024±0.006; euhydrated, 1.018±0.007; mild-dehydrated, 1.030±0.003; ad libitum, 1.021±0.008, pCONCLUSION: When subjects were mildly dehydrated, sleep duration was longer while it was more difficult to fall asleep. More research is necessary, but the results of this study suggest it may be important to maintain euhydration to fall asleep easier

Leukocyte Subset Changes in Response to a 164-km Road Cycle Ride in a Hot Environment

International Journal of Exercise Science 9(1): 34-46, 2016. The purpose of this observational study was to determine the circulating leukocyte subset response to completing the 2013 Hotter’N Hell Hundred recreational 164-km road cycle event in a hot and humid environmental condition. Twenty-eight men and four women were included in this study. Whole blood samples were obtained 1-2 hours before (PRE) and immediately after (POST) the event. Electronic sizing/sorting and cytometry were used to determine complete blood counts (CBC) including neutrophil, monocyte, and lymphocyte subsets. The concentration of circulating total leukocytes (103·µL-1) increased 134% from PRE to POST with the greatest increase in neutrophils (319%, p\u3c0.0001). Circulating monocytes (including macrophages) increased 24% (p=0.004) and circulating lymphocytes including B and T cells increased 53% (p\u3c0.0001). No association was observed between rolling time or relative intensity and leukocyte subset. Completing the Hotter n’ Hell Hundred (HHH), a 100 mile recreational cycling race in extreme (hot and humid) environmental conditions, induces a substantial increase in total leukocytes in circulation. The contribution of increases in specific immune cell subsets is not equal, with neutrophils increasing to greater than 4-fold starting values from PRE to POST race. It is likely that exercise in stressful environmental conditions affects the complement of circulating immune cells, although activational state and characterization of specific leukocyte subsets remains unclear. The observed increase in circulating cell sub-populations suggests that the circulating immune surveillance system may be acutely affected by exercise in hot and humid conditions

Risk factors for Hodgkin's disease by Epstein-Barr virus (EBV) status: prior infection by EBV and other agents

A UK population-based case–control study of Hodgkin's disease (HD) in young adults (16–24 years) included 118 cases and 237 controls matched on year of birth, gender and county of residence. The majority (103) of the cases were classified by Epstein–Barr virus (EBV) status (EBV present in Reed–Stenberg cells), with 19 being EBV-positive. Analyses using conditional logistic regression are presented of subject reports of prior infectious disease (infectious mononucleosis (IM), chicken pox, measles, mumps, pertussis and rubella). In these analyses HD cases are compared with matched controls, EBV-positive cases and EBV-negative cases are compared separately with their controls and formal tests of differences of association by EBV status are applied. A prior history of IM was positively associated with HD (odds ratio (OR) = 2.43, 95% confidence interval (CI) = 1.10–5.33) and with EBV-positive HD (OR = 9.16, 95% CI = 1.07–78.31) and the difference between EBV-positive and EBV-negative HD was statistically significant (P = 0.013). The remaining infectious illnesses (combined) were negatively associated with HD, EBV-positive HD and EBV-negative HD (in the total series, for ≥2 episodes compared with ≤1, OR = 0.45, 95% CI = 0.25–0.83). These results support previous evidence that early exposure to infection protects against HD and that IM increases subsequent risk; the comparisons of EBV-positive and EBV-negative HD are new and generate hypotheses for further study. © 2000 Cancer ResearchCampaig

ULTRAENDURANCE CYCLING IN A HOT ENVIRONMENT: THIRST, FLUID CONSUMPTION, AND WATER BALANCE

ABSTRACT Armstrong, LE, Johnson, EC, McKenzie, AL, Ellis, LA, and Williamson, KH. Ultraendurance cycling in a hot environment: thirst, fluid consumption, and water balance. J Strength Cond Res 29(4): 869-876, 2015-The purpose of this field investigation was to identify and clarify factors that may be used by strength and conditioning professionals to help athletes drink adequately but not excessively during endurance exercise. A universal method to accomplish this goal does not exist because the components of water balance (i.e., sweat rate, fluid consumed) are different for each athlete and endurance events differ greatly. Twenty-six male cyclists (mean 6 SD; age, 41 6 8 years; height, 177 6 7 cm; body mass, 81.85 6 8.95 kg) completed a summer 164-km road cycling event in 7.0 6 2.1 hours (range, 4.5-10.4 hours). Thirst ratings, fluid consumed, indices of hydration status, and body water balance (ingested fluid volume 2 [urine excreted + sweat loss]) were the primary outcome variables. Measurements were taken before the event, at designated aid stations on the course (52, 97, and 136 km), and at the finish line. Body water balance during exercise was not significantly correlated with exercise time on the course, height, body mass, or body mass index. Thirst ratings were not significantly correlated with any variable. We also observed a wide range of total sweat losses (4.9-12.7 L) and total fluid intakes (2.1-10.5 L) during this ultraendurance event. Therefore, we recommend that strength and conditioning professionals develop an individualized drinking plan for each athlete, by calculating sweat rate (milliliter per hour) on the basis of body mass change (in kilograms), during field simulations of competition

Ergogenic effects of betaine supplementation on strength and power performance

<p>Abstract</p> <p>Background</p> <p>We investigated the ergogenic effects of betaine (B) supplementation on strength and power performance.</p> <p>Methods</p> <p>Twelve men (mean ± SD age, 21 ± 3 yr; mass, 79.1 ± 10.7 kg) with a minimum of 3 months resistance training completed two 14-day experimental trials separated by a 14-day washout period, in a balanced, randomized, double-blind, repeated measures, crossover design. Prior to and following 14 days of twice daily B or placebo (P) supplementation, subjects completed two consecutive days (D1 and D2) of a standardized high intensity strength/power resistance exercise challenge (REC). Performance included bench, squat, and jump tests.</p> <p>Results</p> <p>Following 14-days of B supplementation, D1 and D2 bench throw power (1779 ± 90 and 1788 ± 34 W, respectively) and isometric bench press force (2922 ± 297 and 2503 ± 28 N, respectively) were increased (p < 0.05) during REC compared to pre-supplementation values (1534 ± 30 and 1498 ± 29 W, respectively; 2345 ± 64 and 2423 ± 84 N, respectively) and corresponding P values (1374 ± 128 and 1523 ± 39 W; 2175 ± 92 and 2128 ± 56 N, respectively). Compared to pre-supplementation, vertical jump power and isometric squat force increased (p < 0.05) on D1 and D2 following B supplementation. However, there were no differences in jump squat power or the number of bench press or squat repetitions.</p> <p>Conclusion</p> <p>B supplementation increased power, force and maintenance of these measures in selected performance measures, and these were more apparent in the smaller upper-body muscle groups.</p