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We have previously shown that acute exercise increases the level of sphingosine-1-phosphate (S1P) in plasma and ceramide in erythrocytes of untrained subjects. The aim of the current study was to examine the effect of ultramarathon run on the plasma and erythrocyte levels of the following bioactive sphingolipids: S1P, sphinganine-1-phosphate (SA1P), sphingosine, sphinganine, and ceramide. Blood samples were collected from seven male amateur runners participating in a 48-hr ultramarathon race before the run, after 24 and 48 hr of running, and following 24 and 48 hr of recovery. The sphingolipids were quantified by means of HPLC. Sustained running for 48 hr resulted in a progressive decline in plasma S1P to a level significantly lower than at prerace, and then remained stable over the next 48 hr of recovery. In erythrocytes, S1P content was stable until 24 hr of recovery, then rose abruptly to reach peak values after 48 hr of recovery. The plasma level of SA1P decreased progressively during the competition and remained unchanged over the recovery. In erythrocytes, the level of SA1P increased after 24 hr running and normalized thereafter. The level of ceramide, both in plasma and erythrocytes, was not significantly affected by the ultraendurance run. We speculate that reduction in plasma level of S1P during and after the run reduces its biological actions and might be responsible for some negative side-effects of the ultraendurance effort.

Inflammatory markers such as C-reactive protein (CRP), fibrinogen, and white-blood-cell (WBC) count are strongly associated with cardiovascular disease. The authors’ purpose was to compare the inflammatory response to a single aerobic-exercise session between individuals of high and moderate fitness. Ten apparently healthy highly ft and 11 moderately ft men expended 500 kcal at 70% of VO_2peak. Fasting blood samples were obtained on 2 consecutive days before and again at 24, 72, and 120 h post exercise. Blood samples were analyzed for CRP, fibrinogen, and WBC count. CRP was 76% lower at baseline in the highly ft group than in the moderately ft group (P = 0.03). CRP, fibrinogen, and WBC count remained unaltered, however, in the days after exercise (P > 0.05 for all). These findings suggest that markers of inflammation are stable in the days after a single session of moderate-intensity aerobic exercise in apparently healthy men of at least average fitness.

The purpose of this study was to quantify the variability and stability of 1st morning body mass (BM) fluctuations during daily exercise in the heat while following traditional fluid intake guidance. Data from 65 men were examined retrospectively. BM fluctuations were monitored over 4 to 15 consecutive days. Group daily variation in BM was 0.51 ± 0.20 kg. Group coefficient of variation was 0.66 ± 0.24%, normally distributed, and not related to either absolute BM (r = 0.04) or number of measurements (r = 0.34). Three days resulted in a similar variability estimate compared to 6 or 9 d, although precision was improved with 9 d. In conclusion, 3 consecutive BM measurements provide an accurate assessment of daily BM variability, which is less than 1% for active men when replacing 100% of sweat losses during exercise. The data also suggest that daily BM is a sufficiently stable physiological parameter for potential daily fluid balance monitoring.

Advancing age is associated with a reduction in skeletal muscle protein, muscle strength, muscle quality, and chemical modifications that may impair protein function. Sarcopenia has been coupled with physical disability, frailty, and a loss of independent function (5, 19). Using stable isotope tracer methodologies and mass spectrometric detection, we observed: (a) 76–92-year-old physically frail and 62–74-year-old middle-age adults have lower mixed muscle protein synthetic rates than 20–32-year-old men and women; (b) 2 weeks and 3 months of weightlifting exercise increased the synthetic rate of myosin heavy chain (MHC) and mixed muscle proteins to a similar magnitude in frail, middle-age, and young women and men; (c) Serum myostatin-immunoreactive protein levels were elevated in physically frail women and were inversely correlated with lean mass. This suggests that the protein synthetic machinery adapts rapidly to increased contractile activity and that the adaptive response(s) are maintained even in frail elders.

The purpose of this study was to examine changes in nutrition knowledge, intakes, attitudes, and behaviors as well as health status of 22 female adolescent runners. Subjects completed questionnaires, interviews, and dietary analyses twice over a 3-year period. Over this time they experienced physical growth and improved athletic performance. Although their mean score on a test of basic and sports nutrition knowledge remained stable at 67%, after 3 years more runners correctly responded to statements about carbohydrate and fat. However, fewer responded correctly to statements regarding fluid intake and skipping meals. Although runners increased the percentage of calories consumed as carbohydrates, they significantly decreased their mean energy intake, thus lowering carbohydrate intake. They significantly lowered protein, calcium, potassium, and sodium intakes. The incidence of possible eating disorders increased, as did stress fractures. Over 3 years, nutrition knowledge did not improve, the quality of dietary intakes decreased, incidence of eating disorders and stress fractures increased, and menstrual irregularities remained high.

The resting metabolic rate (RMR) and thermic effect of a meal (TEM) were determined in 13 low-energy intake (LOW) and 11 adequate-energy intake (ADQ) male endurance athletes. The LOW athletes reported eating 1,490 kcal·day^-1 less than the ADQ group, while the activity level of both groups was similar. Despite these differences, both groups had a similar fat-free mass (FFM) and had been weight stable for at least 2 years. The RMR was significantly lower (p<0.05) in the LOW group compared to the values of the ADQ group (1.19 vs. 1.29 kcal·FFM^-1·hr^-l, respectively); this difference represents a lower resting expenditure of 158 kcal·day^-1. No differences were found in TEM between the two groups. These results suggest that a lower RMR is one mechanism that contributes to weight maintenance in a group of low- versus adequate-energy intake male athletes.

This study assessed the effect of resistive training (RT), with or without high-dose chromium picolinate (Cr-pic) supplementation, on body composition and skeletal muscle size of older women. Seventeen sedentary women, age range 54-71 years. BMI 28.8±2.4 kg/m². were randomly assigned (double-blind) to groups (Cr-pic. n = 9; Placebo, n = 8) that consumed either 924 μg Cr/d as Cr-pic or a low-Cr placebo (<0.2 μg Cr/d) during a 12-week RT program (2 day/ week, 3 sets · exercise⁻¹ · d¹,80% of 1 repetition maximum). Urinary chromium excretion was 60-fold higher in the Cr-pic group, compared to the Placebo group (p < .001), during the intervention. Resistive training increased maximal strength of the muscle groups trained by 8 to 34% (p < .001), and these responses were not influenced by Cr-pic supplementation. Percent body fat and fat-free mass were unchanged with RT in these weight-stable women, independent of Cr-pic supplementation. Type I and type II muscle fiber areas of the m. vastus lateralis were not changed over time and were not influenced by Cr-pic supplementation. These data demonstrate that high-dose Cr-pic supplementation did not increase maximal strength above that of resistive training alone in older women. Further, these data show that, under these experimental conditions, whole body composition and skeletal muscle size were not significantly changed due to resistive training and were not influenced by supplemental chromium picolinate.

Female athletes should aim to achieve energy balance to maintain health and have a high performance output. The purpose of this study was to investigate energy availability (EA) among members of a medium-size Canadian Interuniversity Sport women’s volleyball team and to describe exercise energy expenditure (ExEE) during practices, game warm-ups, and games. Total daily energy expenditure was assessed over 7 d using the Bodymedia Sensewear Mini armband, while energy intake (EI) was measured with dietary food logs. Body composition was assessed using air-displacement plethysmography (Bod Pod). Energy availability was calculated using the equation EA = (EI_kcal – ExEE_kcal)/kg fat-free mass (FFM). Participants consumed 3,435 (± 1,172) kcal/day and expended 3479 (± 604) kcal/day. Mean EA was 42.5 kcal · kg FFM^-1 · d^-1 across all 7 d, and 2 participants fell below the 30-kcal · kg FFM^-1 · d^-1 threshold. Furthermore, participants expended 511 (± 216), 402 (± 50), and 848 (± 155) kcal during practices, game warm-ups, and games, respectively. Overall, the participants were relatively weight stable and should be encouraged to continue fueling their exercise and high ExEE needs with appropriate nutritional strategies.

The purpose of this study was to examine the effects of ginseng extract ingestion on physiological responses to intense exercise. Subjects performed a control ride (CN) on a cycle ergometer, followed by placebo (PL) and ginseng (GS) treatments. Ginseng was ingested as 8 or 16 mg/kg body weight daily for 7 days prior to trial GS. Venous blood was sampled for FFA, lactate, and glucose analyses. Due to similar findings for both dose groups, the subjects were considered as one group. Lactate, FFA, ${\text{VO}}_2$ , ${\text{V}}_{\mathrm{E}}$ , and RPE increased significantly from 10 through 40 min. RER increased during the first 10 min of exercise and then remained stable, with no intertrial differences. Glucose did not vary significantly from 0 to 40 min or among treatments. RPE was significantly greater and time to exhaustion was significantly less during trial CN than PL or GS, while PL and GS trials were similar. The data indicated that with 1 week of pretreatment there is no ergogenic effect of ingesting the ginseng saponin extract.