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Little is known regarding the dietary intake of non-elite athletes involved in multisport endurance events. The primary objective of this observational study was to characterize the dietary intake of non-elite athletes participating in winter triathlon (snowshoeing, skating, and cross-country skiing), winter pentathlon (winter triathlon sports + cycling and running), Ironman (IM: swimming, cycling, running), and half-distance Ironman (IM 70.3) in relation with current sports nutrition recommendations. A total of 116 non-elite athletes (32 women and 84 men) who had participated in one of those events in 2014 were included in the analyses. Usual dietary intake was assessed using a validated online food frequency questionnaire. Participants (22-66 years old) trained 14.8 ± 5.3 h/week, on average (±SD). Only 45.7% [95% confidence interval, 36.4%-55.2%] of all athletes reported consuming the recommended intake for carbohydrates, with the highest proportion (66.7%) seen in IM athletes. On the other hand, 87.1% [79.6%-92.6%] of all athletes reported consuming at least 1.2 g protein·kg−1·day−1, while 66.4% [57.0%-74.9%] reported consuming more than 1.6 g protein·kg−1·day−1. The proportion of athletes consuming the recommended amount of protein was highest (84.6%) among IM athletes. There was no difference in the proportion of athletes achieving the recommended carbohydrate and protein intakes between men and women. These findings suggest that many non-elite multisport endurance athletes do not meet the current recommendations for carbohydrates, emphasizing the need for targeted nutritional education. Further research is needed to examine how underreporting of food intake may have affected these estimates. [ABSTRACT FROM AUTHOR]

To understand the molecular mechanisms of adaptation to different training protocols, this study compared the effects of 4 sessions of 90 min treadmill exercise on alternate days or consecutive days in 1 week on messenger RNA (mRNA) and protein expression of proliferator-activated receptor-γ coactivator 1-α in rat gastrocnemius muscle. The mRNA significantly increased by 25.8-fold after alternate-day and 10.1-fold after consecutive-day training, while the protein showed no significant cumulative effect, 1.5-1.7-fold above baseline, in the 2 protocols. [ABSTRACT FROM AUTHOR]

Low-fat milk is thought to be an effective postexercise rehydration beverage in adults; however, little is known about milk's rehydration ability in children after exercising in the heat. This study tested the hypothesis that because of its electrolyte and protein content, skim milk (SM) would be more effective than both water (W) and a carbohydrate/electrolyte solution (CES) in replacing body fluid losses in children following exercise in the heat. Thirty-eight (19 females) heat-acclimated pre- to early pubertal (PEP, aged 7-11 years) and mid- to late-pubertal (MLP, aged 14-17 years) children performed 3 sessions in 34.5 °C, 47.3% relative humidity, consisting of 2 × 20-min cycling bouts at 60% peak oxygen uptake followed by consumption of either W, CES, or SM. Each beverage was consumed immediately after exercise in a volume equal to 100% of their body mass loss during exercise. Urine samples were collected before, during, and after exercise, as well as the 2-h period following beverage consumption. On average, children dehydrated 1.3% ± 0.4%. Children ingested 0.40 ± 0.11 L (PEP) and 0.74 ± 0.20 L (MLP) of fluid. The fraction of the ingested beverage retained at 2 h of recovery was greater with SM (74% ± 18%) than W (47% ± 26%) and CES (59% ± 20%, p < 0.001 for both), and greater in CES than W ( p < 0.001). All participants were in a hypohydrated state after 2 h of recovery, following the pattern SM < CES < W. In both PEP and MLP children, SM is more effective than W and CES at replacing fluid losses that occur during exercise in the heat. [ABSTRACT FROM AUTHOR]

Modulation of β-adrenergic receptor (β-AR) activity affects muscle mass and could have a role in the reduction of muscle mass observed following spinal cord transection (Tx). The aims of this study were to examine the early acute effects of Tx on muscle mass, total and myofibrillar protein concentrations, cytochrome c oxidase activity, and β-AR density of skeletal muscle, to ascertain if any change in muscle properties could be related to β-AR signalling events. Female Sprague–Dawley rats (n = 33; ~255 g) were randomly assigned to 4 experimental groups: control 4 d, control 8 d, Tx 4 d, and Tx 8 d. A complete Tx was performed surgically at the T10 cord level. Compared with controls, muscle mass and muscle – body mass ratios decreased significantly following Tx, with no significant change observed in total and myofibrillar protein concentrations. Spinal cord Tx also resulted in a significant decrease in plantaris cytochrome c oxidase activity by 24% at Tx 4 d and 28% at Tx 8 d (p < 0.05). β-AR density of the lateral gastrocnemius was unchanged; however, the β-AR density of the forelimb triceps brachii m. was found to increase after Tx. Our results suggest that changes in muscle mass and cytochrome c oxidase activity rapidly occur after Tx and do not appear to be related to changes in β-AR density. [ABSTRACT FROM AUTHOR]

This symposium addressed recent evidence suggesting that nutritional intervention and resistance-training strategies may be important for aging bone and muscle. The physiological consequences of aging and the potential mechanistic actions of nutritional aids during resistance training were emphasized. [ABSTRACT FROM AUTHOR]