Carbohydrate mouth rinsing decreases fatigue index of taekwondo frequency speed of kick test.

Carbohydrate mouth rinsing (CMR) potentially affects the interval training performance of taekwondo athletes. This study explored the effect of CMR on vertical jump, kicking speed, and fatigue index before and after simulated taekwondo competition. In a crossover experimental design, 13 trained taekwondo athletes were randomly divided into the CMR and control trials. After warming up, the participants used 6.6% maltodextrin (CMR trial) or mineral water (control trial) to rinse their mouth. Next, the participants underwent tests of vertical jump, kicking speed, and maximum number of kicks. After the tests, the participants rinsed their mouth again, followed by using Wingate testing bikes for 5-s sprint and 25-s rest to simulate taekwondo competitions. Four repetitions were performed in each round for 2 min for a total of three rounds. The results revealed that the fatigue index of the participants in the CMR trial before and after the simulated competition was significantly lower than that of the control trial. However, the two trials differed nonsignificantly in their performance in vertical jump, kicking speed, and the simulated competition. Overall, the study results indicated that CMR reduces the fatigue index but no change was observed in performance for vertical jump, kicking speed, and the simulated competition of trained taekwondo athletes.

Thirty minutes of moderate-intensity downhill or level running has no effect on postprandial lipemia: A randomized controlled trial.

Elevated postprandial triglyceride (TG) concentrations are linked to a relatively high risk of cardiovascular disease. Eccentric endurance exercise, such as downhill walking and running, can provide metabolic benefits similar to concentric exercise. However, whether eccentric exercise affects postprandial lipemia remains unknown. Nine healthy young men performed level running (trial) or downhill running (DR trial, -15% slope) at 60% [INSIDE:1]O2max or rest (CON trial) for 30 min in a randomized crossover design. The participants were fed a high-fat meal the next day. Blood and expired gas samples were collected before and 0.5, 1, 2, 3, 4, 5, and 6 h after the meal. Muscle soreness was measured using a visual analog scale. The DR trial induced mild muscle damage. During the 6-h postprandial period, serum TG concentrations and area under the curve (AUC) were similar across the three trials. The DR trial had a significantly higher AUC of nonesterified fatty acid concentrations and a significantly lower AUC of glucose concentrations than the CON trial. The results suggested that neither moderate-intensity DR nor running a level surface had a significant effect on lipemia after a high-fat meal. However, DR improved the postprandial glycemic response.

High fat meals increases postprandial fat oxidation rate but not postprandial lipemia.

BACKGROUND: This study investigated the effects of ingesting meals with the same calorie intake but distinct nutritional contents after exercise on postprandial lipemia the next day. METHODS: Eight healthy male participants completed two 2-day trials in a random order. On day 1, the participants underwent five 12 min bouts of cycling exercise with a bout of higher intensity exercise (4 min) after each and then a bout of lower intensity cycling (2 min). The total exercise time was 90 min. After the exercise, the participants ingested three high-fat or low-fat meals. On Day 2, the participants were asked to rest in the laboratory and ingest a high-fat meal. Their postprandial reaction after a high-fat meal was observed. RESULTS: Postprandial triglyceride concentrations in the high-fat diet trial and low-fat diet trial exhibited nonsignificant differences. Total TG AUC were no significantly different on HF trial and LF trial (HF: 6.63 ± 3.2; LF: 7.20 ± 3.4 mmol/L*4 h. p = 0.586). However, the postprandial fat oxidation rate total AUC (HF: 0.58 ± 0.1; LF: 0.39 ± 0.2 g/min*4 h. p = 0.045), plasma glucose, and insulin concentration of the high-fat trial were significantly higher than those of the low-fat trial. CONCLUSIONS: This study revealed that meals with distinct nutritional contents after a 90-min exercise increased the postprandial fat oxidation rate but did not influence the postprandial lipemia after a high-fat meal the next day.

Damage and the repeated bout effect of arm, leg, and trunk muscles induced by eccentric resistance exercises.

This study compared nine resistance eccentric exercises targeting arm, leg, and trunk muscles in one session for changes in maximal voluntary isometric contraction strength (MVC), delayed onset muscle soreness (DOMS), plasma creatine kinase (CK) activity, and myoglobin (Mb) concentration after the first and second bouts. Fifteen sedentary men (20-25 years) performed 5 sets of 10 eccentric contractions with 80% of MVC load for the elbow flexors (EF), elbow extensors (EE), pectoralis, knee extensors (KE), knee flexors (KF), plantar flexors (PF), latissimus, abdominis, and erector spinae (ES) in a randomized order and repeated the same exercises 2 weeks later. MVC decreased at 1 (16%-57%) to 4 (13%-49%) days, DOMS developed (peak: 43-70 mm), and CK activity (peak: 23 238-207 304 IU/L) and Mb concentration showed large increases after the first bout. The magnitude of decrease in MVC was greater (P < 0.05) for EF, EE, and PEC than others and for KF than KE, PF, and ES. DOMS was greater (P < 0.05) for EF, EE, and ES than others. Changes in all measures were smaller (P < 0.05) after the second than the first bout, and the magnitude of the repeated bout effect was similar among the muscles. Plasma CK activity and Mb concentration did not increase significantly after the second exercise bout. It was concluded that muscle damage was greater for arm than leg muscles, and muscle proteins in the blood increased to a critical level after unaccustomed whole-body resistance exercises, but the magnitude of damage was largely attenuated for all muscles similarly after the second bout.

A Single Bout of Exercise Reduces Postprandial Lipemia but Has No Delayed Effect on Hemorheological Variables.

High plasma triglyceride (TG) concentration in fasting state could cause hemorheological abnormality, thus increasing the incidence of metabolic diseases. Exercise has been reported to effectively reduce postprandial TG response. This study aimed to investigate whether a single bout of pre-prandial exercise can affect lipemia and hemorheological variables after a high-fat meal. Nine healthy young male subjects completed two experimental trials. The subjects walked for 1 h at 50% maximal oxygen uptake (V̇O2max) (the exercise, EX trial), or rested (the control, CON trial). In the next morning, the subjects consumed a high-fat meal, and the postprandial lipemia and hemorheological responses were monitored for 6 h. The results showed that postprandial plasma TG concentrations were significantly lower in the EX trial compared to the CON trial. The postprandial low-density lipoproteins (LDL) concentration declined in the first 2 h and then gradually returned to the baseline level in both trials. The postprandial blood viscosity also decreased in the CON trial. There was no significant difference in postprandial blood viscosity, red blood cell (RBC) deformation index and aggregation degree between the trials. There was no significant correlation between plasma TG concentration and blood viscosity. In conclusion, brisk walking effectively reduced postprandial TG concentration, but has no significant impact on postprandial blood viscosity, RBC deformation index and RBC aggregation index.

Energy replacement using glucose does not increase postprandial lipemia after moderate intensity exercise.

BACKGROUND: Aerobic exercise can decrease postprandial triglyceride (TG) concentrations but the relationship between exercise-induced energy deficits and postprandial lipemia is still unclear. The aim of the present study was to examine the effect of a single bout of aerobic exercise, with and without energy replacement, on postprandial lipemia and on peripheral blood mononuclear cell (PBMC) mRNA expression of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) receptors and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR). METHODS: Nine healthy male humans completed three two-day trials in a random order. On day 1, volunteers rested (CON), completed 60 minutes of treadmill walking at 50% of VO2peak (EX) or completed the same bout of walking but with the energy replaced afterwards with a glucose solution (EXG). On day 2, volunteers rested and consumed a high fat test meal in the morning. RESULTS: Total and incremental TG AUC were significantly lower on the EXG (P < 0.05) and EX (P < 0.05) trials than the CON trial with no difference between the two exercise trials. No significant difference was observed in VLDL or LDL receptor mRNA expression among the trials (P > 0.05). CONCLUSIONS: In conclusion, energy replacement by glucose did not affect the decrease in postprandial TG concentrations observed after moderate intensity exercise and exercise does not affect changes in PBMC HMGCR, VLDL and LDL receptor mRNA expression.

Carbohydrate Mouth Rinses before Exercise Improve Performance of Romanian Deadlift Exercise: A Randomized Crossover Study.

(1) Background: This study compared the effects of mouth rinsing with a carbohydrate trial (CMR) and a placebo trial (PL) on concentric and eccentric contraction strength in multi-joint resistance exercise performance. (2) Methods: Twenty healthy adult men (age: 22.4 ± 3.7 years, body mass index: 26 ± 3.8, peak power: 378.3 ± 138.7 W) were recruited in this study. Participants were employed in a double-blind, randomized crossover design to divide participants into carbohydrate mouth rinsing trial (CMR) and placebo trial (PL). After warming up, participants used 6.6% maltodextrin (CMR) or mineral water (PL) to rinse their mouth for 20 s. Next, the participants underwent tests of maximum inertial Romanian deadlift resistance exercise comprising five sets of six reps, with 3 min rests between sets. After deducting the first repetition of each set, the mean values from the five sets were analyzed. (3) Results: The concentric peak power of the CMR trial was significantly higher than that of the PL trial (p = 0.001, Cohen's d = 0.46), the eccentric peak power of the CMR trial was significantly higher than that of the PL trial (p = 0.008, Cohen's d = 0.56), and the total work of the CMR trial was significantly higher than that of PL trial (p = 0.002, Cohen's d = 0.51). (4) Conclusions: These findings demonstrate that mouth rinsing with carbohydrates before exercise can improve concentric and eccentric contraction strength in multi-joint resistance exercise performance.

Walking Exercise Reduces Postprandial Lipemia but Does Not Influence Postprandial Hemorheological Properties and Oxidative Stress.

A higher postprandial triglycerides response and hemorheological abnormalities may increase the incidence of metabolic disorders and negatively interfere with the aging process. A single session of preprandial endurance exercise was found to be effective in reducing triglyceride levels after a high-fat diet. However, whether the exercise-induced reduction in postprandial triglyceride levels influences hemorheological indicators remains unknown. This study aims to investigate the effects of postprandial lipemia on hemorheological properties and oxidative stress. Eight healthy young male participants completed two experimental trials. On day 1, the participants were randomly assigned to walk for 1 h at 50% VO2max (EE trial) or rest (CON trial). On day 2, participants rested and consumed a high-fat meal in the morning. Results: The postprandial area under the curve (AUC) of plasma TG concentration was significantly lower in EE compared to CON (EE: 9.2 ± 1.9; CON: 10.9 ± 1.7 mmol/L·h−1; p = 0.013; Cohen's d = 0.036). No significant difference was observed in hemorheological properties and MDA (p > 0.05). Endurance exercise effectively decreased postprandial TG concentration but did not influence the postprandial hemorheological properties and oxidative stress indicators.

High-Intensity Intermittent Exercise Increases Fat Oxidation Rate and Reduces Postprandial Triglyceride Concentrations.

(1) Background: This study investigated the effect of acute barehanded whole body high-intensity intermittent exercise (HIIE) and moderate intensity and continuous exercise (MICE) at the same quantity of energy expenditure on postprandial triglyceride (TG) concentrations. (2) Methods: Nine healthy males completed three trials (HIIE, MICE and control (CON)) in a random order separated by at least 14 days. After each intervention, the participants rested for 12 h and consumed a high-fat test meal on the next day. The blood samples and respiratory exchange ratio were observed in the fasted state and for 4 h after consuming the test meal. (3) Results: The HIIE had a significantly higher area under the curve of postprandial fat oxidation rate than MICE (p = 0.027) and CON (p = 0.035) and exhibited significantly lower postprandial TG concentration than the MICE and CON at 2 and 4 h after the test meal. Moreover, the HIIE displayed a higher postprandial TG concentration area under the curve than MICE (p = 0.013) and CON (p = 0.048). (4) Conclusions: The present study concluded that acute barehanded whole body HIIE could significantly lower postprandial TG concentrations. It possibly can induce a rise in the postprandial fat oxidation rate.

The Influence of Pre-Exercise Glucose versus Fructose Ingestion on Subsequent Postprandial Lipemia.

Ingestion of low glycemic index (LGI) carbohydrate (CHO) before exercise induced less insulin response and higher fat oxidation than that of high GI (HGI) CHO during subsequent exercise. However, the effect on the subsequent postprandial lipid profile is still unclear. Therefore, the aim of this study was to investigate ingestion of CHO drinks with different GI using fructose and glucose before endurance exercise on the subsequent postprandial lipid profile. Eight healthy active males completed two experimental trials in randomized double-blind cross-over design. All participants ingested 500 mL CHO (75 g) solution either fructose (F) or glucose (G) before running on the treadmill at 60% VO2max for 1 h. Participants were asked to take an oral fat tolerance test (OFTT) immediately after the exercise. Blood samples were obtained for plasma and serum analysis. The F trial was significantly lower than the G trial in TG total area under the curve (AUC; 9.97 ± 3.64 vs. 10.91 ± 3.56 mmol × 6 h/L; p = 0.033) and incremental AUC (6.57 ± 2.46 vs. 7.14 ± 2.64 mmol/L × 6 h, p = 0.004). The current data suggested that a pre-exercise fructose drink showed a lower postprandial lipemia than a glucose drink after the subsequent high-fat meal.