Appetite Regulations After Sprint Exercise Under Hypoxic Condition in Female Athletes.

Kojima, C, Kasai, N, Ishibashi, A, Murakami, Y, Ebi, K, and Goto, K. Appetite regulations after sprint exercise under hypoxic condition in female athletes. J Strength Cond Res 33(7): 1773-1780, 2019-The present study determined changes in appetite-regulating hormones and energy intake after high-intensity interval exercise (HIIT) under hypoxic conditions (HYP) in trained female athletes. Fifteen female athletes completed 3 trials on different days of either HIIT under HYP, HIIT under normoxic conditions (NOR), or rest in normoxia (CON). Exercise trials consisted of 2 successive sets of 8 repeated bouts of a 6-second maximal sprint separated by a 30-second rest. Blood samples were obtained to measure plasma acylated ghrelin, glucagon-like peptide-1 (GLP-1), and metabolite concentrations. Energy intake during an ad libitum buffet meal test was evaluated 30 minutes after exercise or rest. Plasma acylated ghrelin concentrations decreased significantly after exercise (p ≤ 0.001), but no difference was observed between the HYP and NOR. Plasma GLP-1 concentrations did not differ after exercise, with no difference between the HYP and NOR. Although absolute energy intake in the HYP (634 ± 67 kcal) and NOR (597 ± 63 kcal) was significantly lower than that in the CON (756 ± 63 kcal, p = 0.006), no difference was observed between the HYP and NOR. These results show that HIIT under hypoxic and NOR lowered plasma acylated ghrelin concentrations and energy intake.

Exogenous glucose oxidation during endurance exercise under low energy availability.

The present study was conducted to determine the effect of endurance exercise under low energy availability (EA) on exogenous glucose oxidation during endurance exercise. Ten active males (21.4 ± 0.6 years, 170.4 ± 1.4 cm, 62.4 ± 1.5 kg, 21.5 ± 0.4 kg/m2) completed two trials, consisting of two consecutive days (days 1 and 2) of endurance training under low EA (19.9 ± 0.2 kcal/kg fat free mass [FFM]/day, LEA trial) or normal EA (46.4 ± 0.1 kcal/kg FFM/day, NEA trial). The order of these two trials was randomized with at least a 1-week interval between trials. As an endurance training, participants performed 60 min of treadmill running at 70% of maximal oxygen uptake ([Formula: see text]) during two consecutive days (on days 1 and 2). On day 1, the endurance training was performed with consumed individually manipulated meals. During the endurance exercise on day 2, exogenous glucose oxidation was evaluated using 13C-labeled glucose, and respiratory gas samples were collected. In addition, blood glucose and lactate concentrations were measured immediately after exercise on day 2. Body composition, blood parameters, and resting respiratory gas variables were evaluated under overnight fasting on days 1 and 2. Body weight was significantly reduced in the LEA trial on day2 (day1: 61.8 ± 1.4 kg, day 2: 61.3 ± 1.4 kg, P < 0.001). There were no significant differences between trials in 13C excretion (P = 0.33) and area under the curve during the 60 min of exercise (LEA trial: 40.4 ± 3.1 mmol•60min, NEA trial: 40.4 ± 3.1 mmol•60min, P = 0.99). However, the respiratory exchange ratio (RER, LEA trial: 0.88 ± 0.01, NEA trial: 0.90 ± 0.01) and carbohydrate oxidation (LEA trial: 120.1 ± 8.8 g, NEA trial: 136.8 ± 8.6 g) during endurance exercise showed significantly lower values in the LEA trial than in the NEA trial (P = 0.01 for RER and carbohydrate oxidation). Serum insulin and total ketone body concentrations were significantly changed after a day of endurance training under low EA (P = 0.04 for insulin, P < 0.01 for total ketone). In conclusion, low EA during endurance exercise reduced systemic carbohydrate oxidation; however, exogenous glucose oxidation (evaluated by 13C excretion) remained unchanged during exercise under low EA.

Dietary self-efficacy and social support interactions in junior athletes' acquisition of life skills.

Objective: According to the stages of change, this study identified the association between dietary control self-efficacy and social support for healthy diets as factors influencing life skills acquisition in dietary habits among adolescents in Japan. Research design: This cross-sectional study was conducted between April and May 2018 among eight high school baseball teams in Japan. Method: Participants included 180 Japanese high school baseball players. Survey items evaluated life skills (dependent variables), self-efficacy's influence on dietary control, social support (explanatory variables), and stages of change. Hierarchical multiple regression analysis was used to reveal the associations. Results: In the pre-action stage, although there was no significant association between the interaction of self-efficacy and social support on total life skills (ß = 0.11, p = 0.158), a significant association was observed in the action/maintenance stage (ß = 0.32, p < 0.05). The interaction between self-efficacy and social support showed a significant association with goal setting in the pre-action stage (ß = 0.19, p < 0.05) and with communicating in the action/maintenance stage (ß = 0.34, p < 0.05). Conclusion: The acquisition of life skills amidst dietary situations can be facilitated by providing social support that considers self-efficacy in relation to dietary control, according to the stages of change.

The Effect of Ongoing Vitamin D and Low-Fat Milk Intake on Bone Metabolism in Female High-School Endurance Runners.

BACKGROUND: Vitamin D and calcium are essential nutrients for bone health. In addition, vitamin D suppresses inflammatory cytokines and increases bone resorption. Therefore, improvements in bone health by calcium and vitamin D supplementation have the potential to not only improve calcium metabolism but also suppress inflammation associated with exercise training. The purpose of this study was to determine whether ongoing vitamin D supplementation and low-fat milk intake by female high-school endurance runners would improve bone metabolism by suppressing inflammatory cytokines and the parathyroid hormone (PTH). METHODS: Twenty female high-school runners were assigned to a vitamin D supplement and low-fat milk intake group (MKD) or a control group (CON). Participants in the MKD group consumed a vitamin D supplement (1,000 IU/day) and low-fat milk (Ca 315 mg/day) for 6 months. Bone mineral density measurements, blood samples, and questionnaires (regarding menses and diet) were carried out. The UMIN Clinical Trials Registry number is UMIN000027854. RESULTS: The 25-hydroxyvitamin D (25(OH)D) concentration in MKD was sustained and PTH concentration was decreased regardless of the state of menses. The correlation coefficients of 25(OH)D or PTH concentrations and bone metabolism markers were analyzed by partial correlation coefficient via adjusting the model for frequency of menses. CTX and 25(OH)D concentration were significantly and inversely correlated at baseline (r = -0.61, P < 0.01), 3 months (r = -0.54, P = 0.02), and 6 months (r = -0.53, P = 0.02). CTX and PTH were significantly and positively correlated at 3 months (r = 0.63, P < 0.01) and 6 months (r = 0.52, P = 0.02). The bone alkaline phosphatase (BAP)/CTX ratio and 25(OH)D concentration were significantly and positively correlated at 3 months (r = 0.59, P = 0.01) and 6 months (r = 0.56, P = 0.01). The BAP/CTX ratio and PTH were significantly and inversely correlated at 3 months (r = -0.59, P = 0.01) and 6 months (r = -0.58, P < 0.01). CONCLUSIONS: This study suggested that vitamin D and low-fat milk supplementation improves bone metabolism by sustaining the 25(OH)D concentration and decreasing the PTH concentration in female high-school endurance runners regardless of the state of menses.

Post-Exercise Whole Body Cryotherapy (-140 °C) Increases Energy Intake in Athletes.

PURPOSE: The purpose of the present study was to investigate the effect of whole-body cryotherapy (WBC) treatment after exercise on appetite regulation and energy intake. METHODS: Twelve male athletes participated in two trials on different days. In both trials, participants performed high-intensity intermittent exercise. After 10 min following the completion of the exercise, they were exposed to a 3-min WBC treatment (-140 °C, WBC trial) or underwent a rest period (CON trial). Blood samples were collected to assess plasma acylated ghrelin, serum leptin, and other metabolic hormone concentrations. Respiratory gas parameters, skin temperature, and ratings of subjective variables were also measured after exercise. At 30 min post-exercise, energy and macronutrient intake were evaluated during an ad libitum buffet meal test. RESULTS: Although appetite-regulating hormones (acylated ghrelin and leptin) significantly changed with exercise (p = 0.047 for acylated ghrelin and p < 0.001 for leptin), no significant differences were observed between the trials. Energy intake during the buffet meal test was significantly higher in the WBC trial (1371 ± 481 kcal) than the CON trial (1106 ± 452 kcal, p = 0.007). CONCLUSION: Cold exposure using WBC following strenuous exercise increased energy intake in male athletes.

Flavanol-rich cocoa consumption enhances exercise-induced executive function improvements in humans.

OBJECTIVE: Aerobic exercise is known to acutely improve cognitive functions, such as executive function (EF) and memory function (MF). Additionally, consumption of flavanol-rich cocoa has been reported to acutely improve cognitive function. The aim of this study was to determine whether high cocoa flavanol (CF; HCF) consumption would enhance exercise-induced improvement in cognitive function. To test this hypothesis, we examined the combined effects of HCF consumption and moderate-intensity exercise on EF and MF during postexercise recovery. METHODS: Ten healthy young men received either an HCF (563 mg of CF) or energy-matched low CF (LCF; 38 mg of CF) beverage 70 min before exercise in a single-blind counterbalanced manner. The men then performed moderate-intensity cycling exercise at 60% of peak oxygen uptake for 30 min. The participants performed a color-word Stroop task and face-name matching task to evaluate EF and MF, respectively, during six time periods throughout the experimental session. RESULTS: EF significantly improved immediately after exercise compared with before exercise in both conditions. However, EF was higher after HCF consumption than after LCF consumption during all time periods because HCF consumption improved EF before exercise. In contrast, HCF consumption and moderate-intensity exercise did not improve MF throughout the experiment. CONCLUSION: The present findings demonstrated that HCF consumption before moderate-intensity exercise could enhance exercise-induced improvement in EF, but not in MF. Therefore, we suggest that the combination of HCF consumption and aerobic exercise may be beneficial for improving EF.

The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners.

The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX) or a control trial with an identical period of rest (CON). Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36) and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05), plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal) was significantly lower than that in CON (1529 ± 55 kcal), and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (-40.2% to 12.8%). However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners.

Comparison of Site-Specific Bone Mineral Densities between Endurance Runners and Sprinters in Adolescent Women.

We aimed to compare site-specific bone mineral densities (BMDs) between adolescent endurance runners and sprinters and examine the relationship of fat-free mass (FFM) and nutrient intake on BMD. In this cross-sectional study, 37 adolescent female endurance runners and sprinters (16.1 ± 0.8 years) were recruited. BMD and FFM were assessed by dual-energy X-ray absorptiometry. Nutrient intake and menstrual state were evaluated by questionnaires. After adjusting for covariates, spine and total bone less head (TBLH) BMDs were significantly higher in sprinters than endurance runners (TBLH, 1.02 ± 0.05 vs. 0.98 ± 0.06 g/cm²; spine, 0.99 ± 0.06 vs. 0.94 ± 0.06 g/cm²; p < 0.05). There was no significant difference between groups in other sites. The rate of menstrual abnormality was higher in endurance runners compared with sprinters (56.3% vs. 23.8%; p < 0.05). FFM was a significant covariate for BMD on all sites except the spine (p < 0.05). Dietary intake of vitamin D was identified as a significant covariate only for pelvic BMD (p < 0.05). The BMDs of different sites among endurance runners and sprinters were strongly related to FFM. However, the association of FFM with spine BMD cannot be explained by FFM alone. Other factors, including nutrition and/or mechanical loading, may affect the spine BMD.

Daily ingestion of catechin-rich beverage increases brown adipose tissue density and decreases extramyocellular lipids in healthy young women.

PURPOSE: Brown adipose tissue (BAT) contributes to the regulation of non-shivering thermogenesis and adiposity. Increasing BAT has recently attracted much attention as a countermeasure to obesity. Animal studies have shown that prolonged catechin treatment increases uncoupling protein 1, a thermogenic protein in BAT. On the other hand, supportable evidence in human is lacking. Thus, the purpose of this study was to examine whether BAT increases after catechin ingestion in humans. METHODS: Twenty-two healthy young women were given either a catechin-rich (540 mg/day; catechin) or placebo beverage every day for 12 weeks in a double-blind design. BAT density was measured using near-infrared time-resolved spectroscopy (NIRTRS), visceral fat area were measured using magnetic resonance imaging, extramyocellular lipids (EMCL) using proton magnetic resonance spectroscopy, and body fat mass using dual-energy X-ray absorptiometry scans. RESULTS: BAT density was significantly increased (18.8 %), and EMCL was decreased (17.4 %) after the 12-week ingestion. There was a significant negative correlation between the changes in BAT density and those in EMCL (r = -0.66, P < 0.05). There were no notable changes in other parameters. CONCLUSIONS: In conclusion, prolonged ingestion of a catechin-rich beverage increases the BAT density in parallel with a decrease in EMCL.

A 3-day high-fat/low-carbohydrate diet does not alter exercise-induced growth hormone response in healthy males.

OBJECTIVE: The purpose of the present study was to examine the effects of 3 days isoenergetic high-fat/low-carbohydrate diet (HF-LC) relative to low-fat/high-carbohydrate diet (LF-HC) on the exercise-induced growth hormone (GH) response in healthy male subjects. DESIGN: Ten healthy young males participated in this study. Each subject consumed the HF-LC (18±1% protein, 61±2% fat, 21±1% carbohydrate, 2720 kcal per day) for 3 consecutive days after consuming the LF-HC (18±1% protein, 20±1% fat, 62±1% carbohydrate, 2755 kcal per day) for 3 consecutive days. After each dietary intervention period, the hormonal and metabolic responses to an acute exercise (30 min of continuous pedaling at 60% of V˙O2max) were compared. The intramyocellular lipid (IMCL) contents in the vastus lateralis, soleus, and tibialis anterior were evaluated by proton magnetic resonance spectroscopy. RESULTS: Serum GH concentrations increased significantly during the exercise after both the HF-LC and LF-HC periods (P<0.05). However, the exercise-induced GH response was not significantly different between the two periods. Fat utilization and lipolytic responses during the exercise were enhanced significantly after the HF-LC period compared with the LF-HC period. IMCL content did not differ significantly in any portion of muscle after the dietary interventions. CONCLUSIONS: We could not show that short-term HF-LC consumption changed significantly exercise-induced GH response or IMCL content in healthy young males.