Energy replacement diminishes the effect of exercise on postprandial lipemia in boys

Purpose: Acute bouts of exercise reduce postprandial triacylglycerol concentrations ([TAG]) in healthy boys and girls; however, it is not known whether this effect is mediated by the energy deficit. This study examined whether the exercise-induced reduction in postprandial [TAG] persists after immediate dietary replacement of the exercise energy expenditure (EE). Methods: Eighteen healthy 11- to 13-year-old boys (mean(SD): body mass 41.3(8.4) kg; peak oxygen uptake ( VO 2) 55(5) mL·kg-1·min-1) completed three, 2-day conditions in a within-measures, crossover design separated by 14 days. On day 1, participants rested (CON), exercised at 60% peak VO 2 inducing a net EE of 32 kJ·kg-1 body mass (EX-DEF) or completed the same exercise with the net EE replaced immediately (EX-REP). On day 2, capillary blood samples were taken in the fasted state and at pre-determined intervals throughout the 6.5 h postprandial period. A standardised breakfast and lunch meal were consumed immediately and 4 h, respectively, after the fasting sample. Results: Based on ratios of the geometric means (95% confidence intervals (CI) for ratios), EX-DEF fasting [TAG] was 19% and 15% lower than CON (-32 to -4%, ES = 1.15, P = 0.02) and EX-REP (-29 to 0%, ES = 0.91, P = 0.05) respectively; CON and EX-REP were similar (-4%; P = 0.59). The EX-DEF total area under the [TAG] versus time curve was 15% and 16% lower than CON (-27 to 0%, ES = 0.55, P = 0.05) and EX-REP (-29 to -2%, ES = 0.62, P = 0.03) respectively; CON and EX-REP were not different (2%; -13 to 20%, P = 0.80). Conclusion: Immediate replacement of the exercise-induced energy deficit negates the reduction in postprandial [TAG] in boys; this highlights the importance of maintaining a negative energy balance immediately post-exercise to maximise the metabolic health benefits of exercise

Sex differences in postprandial lipaemia after acute high-intensity interval running in young people

Acute exercise reduces postprandial triacylglycerol concentrations ([TAG]) in boys and girls; however, it is not known whether between-sex differences exist in response to exercise. Fifteen boys (mean(SD): 11.8(0.4) years) and sixteen girls (12.1(0.7) years) completed two, 2-day conditions. On day 1, participants rested (CON) or completed 10×1 min high-intensity interval runs at 100% maximal aerobic speed with 1 min recovery (HIIR). On day 2, participants consumed a standardised breakfast and lunch over a 6.5-h period during which seven capillary blood samples were collected. Based on ratios of the geometric means (95% CI for ratios), fasting [TAG] was 32% lower in boys than girls (-44 to -18%, ES=1.31, P<0.001), and 12% lower after HIIR than CON (-18 to -5%, ES=0.42, P=0.003); the magnitude of reduction was not significantly different between the sexes (8% (ES=0.36) vs. 15% (ES=0.47), respectively; P=0.29). The total area under the [TAG] versus time curve was 27% lower in boys than girls (-40 to -10%, ES=1.02, P=0.005), and 10% lower after HIIR than CON (-16 to -5%, ES=0.36, P=0.001); the magnitude of reduction was similar between the sexes (11% (ES=0.43) vs. 10% (ES=0.31), respectively; P=0.87). The small-moderate reduction in postprandial [TAG] after HIIR was similar between the sexes

Acute exercise and postprandial lipemia in young people

Exaggerated postprandial triacylglycerol concentrations ([TAG]) independently predict future cardiovascular events. Acute exercise and diet interventions attenuate postprandial [TAG] in adults. This paper aims to examine the exercise postprandial lipemia studies published to date in young people. Nine studies satisfied the inclusion criteria adopted for this summary. The majority of studies are in boys (22% girls) and have shown a single ~60 min session of moderate intensity exercise, performed 12 to 16 h before a standardised meal, reduces postprandial [TAG]. Manipulations of exercise duration and intensity suggest an exercise energy expenditure dose-dependent response is not supported directly in healthy young people. Studies investigating alternative exercise bouts have reported lower postprandial [TAG] after simulated intermittent games activity, high intensity interval running and cumulative 10-min blocks over several hours, which may appeal to the spontaneous physical activity habits of young people. Although extension of these initial findings is warranted, exercise may be an effective strategy to promote regular benefits in TAG metabolism in children and adolescents; this may contribute to an improved cardiovascular disease risk profile early in life

Acute effects of energy deficit induced by moderate-intensity exercise or energy-intake restriction on postprandial lipemia in healthy girls

Eleven healthy girls (mean ± SD: age 12.1 ± 0.6 years) completed three 2-day conditions in a counterbalanced, crossover design. On day 1, participants either walked at 60 (2)% peak oxygen uptake (energy deficit 1.55[0.20] MJ), restricted food energy intake (energy deficit 1.51[0.25] MJ) or rested. On day 2, capillary blood samples were taken at predetermined intervals throughout the 6.5 hr postprandial period before, and following, the ingestion of standardized breakfast and lunch meals. Fasting plasma triacylglycerol concentrations (TAG) was 29% and 13% lower than rest control in moderate-intensity exercise (effect size [ES] = 1.39, p = .01) and energy-intake restriction (ES = 0.57, p = .02) respectively; moderate intensity exercise was 19% lower than energy-intake restriction (ES = 0.82, p = .06). The moderate-intensity exercise total area under the TAG versus time curve was 21% and 13% lower than rest control (ES = 0.71, p = .004) and energy-intake restriction (ES = 0.39, p = .06) respectively; energy-intake restriction was marginally lower than rest control (–10%; ES = 0.32, p = .12). An exercise-induced energy deficit elicited a greater reduction in fasting plasma TAG with a trend for a larger attenuation in postprandial plasma TAG than an isoenergetic diet-induced energy deficit in healthy girls

Acute high-intensity interval running reduces postprandial lipemia in boys

INTRODUCTION: Acute moderate-intensity exercise reduces postprandial lipemia in boys. However, the effect of high-intensity exercise has not been investigated. This study examined the effect of low-volume, high-intensity interval running (HIIR) on postprandial plasma triacylglycerol concentrations [TAG]. METHODS: Fifteen healthy, active boys (means(SD): age 11.8(0.4) years; body mass 42.8(8.0) kg; peak oxygen uptake (V ̇2) 55(6) mL·kg·min) completed two, 2-day trials in a counter-balanced, cross-over design separated by 14 days. On day 1, participants rested (CON) or completed 10 x 1 min running intervals at 100% maximal aerobic speed, determined from an incremental peak V ̇2 test, with 1 min recovery between intervals (HIIR). On day 2, capillary blood samples were taken in the fasted state and at pre-determined intervals throughout the 6.5 h postprandial period while participants rested. A standardised breakfast was consumed at 08:00 immediately after the fasting sample and a standardised lunch meal at 12:00. RESULTS: Differences in fasting plasma [TAG] were small to moderate (95% confidence interval (95% CI) -0.11 to 0.01, Effect size (ES) = 0.40). Postprandial [TAG] was lower during HIIR compared with CON (95% CI -0.19 to -0.02, ES = 0.58). The total area under the [TAG] versus time curve was lower following HIIR compared with CON (5.2(1.1) vs. 5.8(1.5) mmol·L 6.5 h; 95% CI -1.18 to -0.12, ES = 0.50). CONCLUSIONS: This is the first study to show that low volume, high-intensity interval running attenuates postprandial [TAG] in healthy, active 11 to 12 year old boys

High-intensity running and energy restriction reduces postprandial lipemia in girls

PURPOSE: This study examined the potency of combining acute high-intensity exercise and energy-intake restriction on postprandial triacylglycerol concentrations ([TAG]) in healthy girls. METHODS: Sixteen 11- to 13-year-old girls (mean(SD): body mass 45.1(7.6) kg; peak oxygen uptake (V˙O2) 43(6) mL·kg·min) completed three, 2-day conditions in a counterbalanced, crossover design separated by 14 days. On day 1, participants completed 10×1 min interval runs (HIIR), 5×1 min interval runs combined with 0.82(0.19) MJ energy-intake restriction (HIIR-ER) or rested (CON). Exercise was completed at 100% maximal aerobic speed, determined from an incremental peak V˙O2 test, with 1 min recovery between intervals. On day 2, capillary blood samples were taken in the fasted state and at pre-determined intervals throughout the 6.5 h postprandial period. A standardised breakfast and lunch were consumed immediately and 4 h, respectively, after the fasting sample. RESULTS: Based on ratios of the geometric means (95% confidence intervals (CI) for ratios), fasting [TAG] was 16% and 8% lower than CON in HIIR (-24 to -7%, effect size (ES) = 0.49, P = 0.002) and HIIR-ER (-17 to 1%, ES = 0.24, P = 0.09) respectively; HIIR was 8% lower than HIIR-ER (-17 to 1%, ES = 0.25, P = 0.08). The total area under the [TAG] versus time curve was 10% and 9% lower than CON in HIIR (-16 to -3%, ES = 0.30, P = 0.01) and HIIR-ER (-15 to -2%, ES = 0.28, P = 0.01) respectively; HIIR-ER and HIIR were similar (-1%; -8 to 6%, P = 0.80). CONCLUSION: Manipulations of HIIR and ER reduce postprandial [TAG] in girls. The magnitude of effect was marginally, though not meaningfully, greater following HIIR than HIIR-ER

Effects of intermittent games activity on postprandial lipemia in young adults

Purpose: To investigate whether a single session of intermittent games activity would reduce postprandial lipemia. Methods: Twelve male volunteers completed three 2-d trials: rest, continuous exercise, and intermittent games activity. Trials were performed a minimum of 6 d apart in a balanced crossover design. In the rest trial, subjects took no exercise on day 1. On day 1 of the continuous and intermittent games trials, subjects completed four blocks (approximately 15 min per block) of uphill treadmill walking or intermittent games activity with 3 min of rest between each block. On day 2, subjects came to the laboratory for an oral fat tolerance test (blood taken fasted and for 6 h following a high-fat test meal (1.25 g of fat and 1.07 g of carbohydrate per kilogram of body mass)). Results: The intermittent games protocol elicited a higher exercise intensity than the continuous trial (lactate: 4.3 ± 0.6 vs 2.4 ± 0.3 mmol·L−1; % V̇O2max: 72 ± 2 vs 62 ± 1, respectively; mean ± SE). The total area under the plasma triacylglycerol (TAG) concentration versus time curve was lower in both the intermittent games (25%, P = 0.001) and the continuous (19%, P = 0.028) trials than in the rest trial. Conclusion: These findings show for the first time that intermittent games activity can reduce postprandial lipemia, and confirm that continuous exercise reduces postprandial lipemia in young adults

The accumulation of exercise and postprandial endothelial function in boys

The purpose of this study was to investigate the effect of accumulating 60min of exercise on endothelial function and triacylglycerol concentrations following the ingestion of a high-fat breakfast and lunch in 14 adolescent boys (aged 12 to 14 years). Two, 2-day main trials (control and exercise) were completed in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial but on day 1 of the exercise trial completed 6×10min runs at 70% of peak oxygen uptake, spread over the day. On day 2, triacylglycerol concentrations and flow-mediated dilation (FMD) were measured prior to, and following, ingestion of the high-fat meals. In the control trial, FMD was reduced by 30% and 33% (P0.05). These results support the concept of accumulating physical activity for health in adolescents as the accumulated exercise attenuated the decline in FMD seen following the consumption of high-fat meals. © 2013 John Wiley & Sons A/S

Increased complexities in visual search behavior in skilled players for a self-paced aiming task

The badminton serve is an important shot for winning a rally in a match. It combines good technique with the ability to accurately integrate visual information from the shuttle, racket, opponent, and intended landing point. Despite its importance and repercussive nature, to date no study has looked at the visual search behaviors during badminton service in the singles discipline. Unlike anticipatory tasks (e.g., shot returns), the serve presents an opportunity to explore the role of visual search behaviors in movement control for self-paced tasks. Accordingly, this study examined skill-related differences in visual behavior during the badminton singles serve. Skilled (n D 12) and less skilled (n D 12) participants performed 30 serves to a live opponent, while real-time eye movements were captured using a mobile gaze registration system. Frame-by-frame analyses of 662 serves were made and the skilled players took a longer preparatory time before serving. Visual behavior of the skilled players was characterized by significantly greater number of fixations on more areas of interest per trial than the less skilled. In addition, the skilled players spent a significantly longer time fixating on the court and net, whereas the less skilled players found the shuttle to be more informative. Quiet eye (QE) duration (indicative of superior sports performance) however, did not differ significantly between groups which has implications on the perceived importance of QE in the badminton serve. Moreover, while visual behavior differed by skill level, considerable individual differences were also observed especially within the skilled players. This augments the need for not just group-level analyses, but individualized analysis for a more accurate representation of visual behavior. Findings from this study thus provide an insight to the possible visual search strategies as players serve in net-barrier games. Moreover, this study highlighted an important aspect of badminton relating to deception and the implications of interpreting visual behavior of players

Effects of caffeine supplementation on performance in ball games

Although a large body of evidence exists documenting the ergogenic properties of caffeine, most studies have focused on endurance performance. However, findings from endurance sports cannot be generalized to performance in ball games where, apart from having a high level of endurance, successful athletic performances require a combination of physiological, technical and cognitive capabilities. The purpose of this review was to critically evaluate studies that have examined the effect of a single dose of caffeine in isolation on one or more of the following performance measures: total distance, sprint performance, agility, vertical jump performance and accuracy in ball games. Searches of three major databases resulted in 19 studies (invasion games: 13; net-barrier games: 6) that evaluated the acute effects of caffeine on human participants, provided the caffeine dose administered, and included a ball games specific task or simulated match. Improvements in sprint performance were observed in 8 of 10 studies (80%), and vertical jump in 7 of 8 studies (88%). Equivocal results were reported for distance covered, agility and accuracy. Minor side effects were reported in 4 of 19 studies reviewed. Pre-exercise caffeine ingestion between 3.0 and 6.0 mg/kg of body mass appears to be a safe ergogenic aid for athletes in ball games. However, the efficacy of caffeine varies depending on various factors, including, but not limited to, the nature of the game, physical status and caffeine habituation. More research is warranted to clarify the effects of caffeine on performance measures unique to ball games, such as agility and accuracy. It is essential that athletes, coaches and practitioners evaluate the risk-benefit ratio of caffeine ingestion strategies on an individual case-by-case basis