Reducing postprandial triglycerides (TG) can lower the risk for cardiovascular disease. The purpose of this study was to perform a meta-analytic review of the literature to estimate the effect of prior exercise on postprandial lipemia. A total of 121 effects were found from 76 studies for the total TG response and 70 effects from 44 studies for the incremental area under the curve (iAUC) TG response. The weighted mean effect was moderate for the total TG response, Cohen's d = -0.60 (P < 0.0001), and for the iAUC response, Cohen's d = -0.59 (P < 0.0001). Moderator analysis revealed women exhibited a larger reduction (P < .01) in the total TG response following exercise (d = -0.96) than men (d = -0.57); high-intensity interval training induced a larger reduction (P < .05) in the iAUC response (d = -1.49) than aerobic (d = -0.58) or resistance (d = -0.13) exercise, and participants maintaining an energy deficit following exercise exhibited a greater reduction in the iAUC response (d = -0.67) compared with participants in energy balance (d = -0.28). We conclude that prior acute exercise reduces postprandial lipemia, with the magnitude of effect influenced by sex, type of exercise, and energy deficit following exercise.

High postprandial blood triglyceride (TG) levels increase cardiovascular disease risk. Exercise interventions may be effective in reducing postprandial blood TG. The purpose of this study was to determine the effects of sprint interval cycling (SIC), with and without replacement of the energy deficit, on postprandial lipemia. In a repeated-measures crossover design, six men and six women participated in three trials, each taking place over 2 days. On the evening of the first day of each trial, the participants either did SIC without replacing the energy deficit (Ex-Def), did SIC and replaced the energy deficit (Ex-Bal), or did not exercise (control). SIC was performed on a cycle ergometer and involved four 30-s all-out sprints with 4-min active recovery. In the morning of day 2, responses to a high-fat meal were measured. Venous blood samples were collected in the fasted state and at 0, 30, 60, 120, and 180 min postprandial. There was a trend toward a reduction with treatment in fasting TG (P = 0.068), but no significant treatment effect for fasting insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate (P > 0.05). The postprandial area under the curve (mmol·l(-1)·3 h(-1)) TG response was significantly lower in Ex-Def (21%, P = 0.006) and Ex-Bal (10%, P = 0.044) than in control, and significantly lower in Ex-Def (12%, P = 0.032) than in Ex-Bal. There was no treatment effect (P > 0.05) observed for area under the curve responses of insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate. SIC reduces postprandial lipemia, but the energy deficit alone does not fully explain the decrease observed.

The purpose of this study was to compare peak cardiorespiratory, metabolic, and perceptual responses to acute bouts of sprint interval cycling (SIC) and a high-intensity intermittent calisthenics (HIC) protocol consisting of modified "burpees." Eleven (8 men and 3 women) moderately trained, college-aged participants (age = 21.9 ± 2.1, body mass index = 24.8 ± 1.9, V[Combining Dot Above]O2peak = 54.1 ± 5.4 ml·kg·min) completed 4 testing sessions across 9 days with each session separated by 48-72 hours. Using a protocol of 4 repeated bouts of 30-second "all-out" efforts interspersed with 4-minute active recovery periods, responses to SIC and HIC were classified relative to peak values. Mean values for %V[Combining Dot Above]O2peak and %HRpeak for SIC (80.4 ± 5.3% and 86.8 ± 3.9%) and HIC (77.6 ± 6.9% and 84.6 ± 5.3%) were not significantly different (p > 0.05). Effect sizes (95% confidence interval) calculated for mean differences were: %V[Combining Dot Above]O2peak Cohen's d = 0.51 (0.48-0.53) and %HRpeak Cohen's d = 0.57 (0.55-0.59). A low-volume, high-intensity bout of repeated whole-body calisthenic exercise induced cardiovascular responses that were not significantly different but were ∼1/2SD lower than "all-out" SIC. These results suggest that in addition to the benefit of reduced time commitment, a high-intensity interval protocol of calisthenics elicits vigorous cardiorespiratory and perceptual responses and may confer physiological adaptations and performance improvements similar to those reported for SIC. The potential efficacy of this alternative interval training method provides support for its application by athletes, coaches, and strength and conditioning professionals.

Repeated, high-intensity sprints were fatiguing, but paradoxical reductions in feelings of fatigue and increases in feelings of energy occurred during recovery that were accounted for by ratings of fatigue during exercise and oxygenation in the dorsolateral prefrontal cortex during recovery.

Our objective was to determine the effects of high-intensity interval training (HIT) on fitness in Army Reserve Officers' Training Corps cadets. Twenty-six college-aged (20.5 ± 1.7 years) participants completed 4 weeks of exercise training 3 days · wk(-1) consisting of either approximately 60 minutes of typical physical training or HIT whole-body calisthenics involving 4 to 7 sets of 30-second "all out" burpees separated by 4 minutes of active recovery. Several pre- and postintervention fitness variables were compared. We observed no changes across time or differences between groups in aerobic capacity, anaerobic capacity, or Army Physical Fitness Test performance (p > 0.05). However, there was a significant Group × Time interaction (p = 0.015) for skeletal muscle mitochondrial function (Tc: time constant of recovery). For the typical physical training group, we observed improved mitochondrial function (Tc decreased 2.4 ± 4.6 seconds; Cohen's d = -0.51); whereas, mitochondrial function decreased in HIT (Tc increased 2.4 ± 4.6 seconds; d = 0.50). HIT sustained fitness despite the short duration and reduced volume of activity. A program that includes HIT as part of a larger program may be well suited for maintaining fitness in moderately trained armed forces personnel without access to equipment.