A Single Bout of Upper-Body Exercise Has No Effect on Postprandial Metabolism in Persons with Chronic Paraplegia

Acute Low Force Electrically Induced Exercise Modulates Post Prandial Glycemic Markers in People with Spinal Cord Injury

Regular exercise involves daily muscle contractions helping metabolize up to 70% of daily ingested glucose. Skeletal muscle increases glucose uptake through two distinct pathways: insulin signaling pathway and muscle contraction mediated AMPK pathway. People with paralysis are unable to contract their muscles which atrophy, transform into insulin resistant glycolytic muscle, and develop osteoporosis. Our goal is to determine if low force electrically induced exercise (LFE) will modulate the post prandial insulin and glucose response in people with and without spinal cord injury (SCI). 18 people with SCI and 23 without SCI (Non-SCI) participated in an assessment of metabolic biomarkers during passive sitting (CTL) and a bout of LFE delivered to the quadriceps/hamstring muscle groups after a glucose challenge. Baseline fasting insulin (p = 0.003) and lactate (p = 0.033) levels were higher in people with SCI, but glucose levels (p = 0.888) were similar compared to the non-SCI population. After 1-h of muscle contractions using LFE, heart rate increased (p < 0.001), capillary glucose decreased (p = 0.004), insulin decreased (p < 0.001), and lactate increased (p = 0.001) in the SCI population. These findings support that LFE attenuates certain metabolic blood biomarkers during a glucose challenge and may offer a lifestyle strategy to regulate metabolic responses after eating among people with SCI.

Effect of Prior Exercise on Postprandial Lipemia: An Updated Meta-Analysis and Systematic Review

The purpose of this systematic review was to synthesize the results from current literature examining the effects of prior exercise on the postprandial triglyceride (TG) response to evaluate current literature and provide future direction. A quantitative review was performed using meta-analytic methods to quantify individual effect sizes. A moderator analysis was performed to investigate potential variables that could influence the effect of prior exercise on postprandial TG response. Two hundred and seventy-nine effects were retrieved from 165 studies for the total TG response and 142 effects from 87 studies for the incremental area under the curve TG response. There was a moderate effect of exercise on the total TG response (Cohen's d = -0.47; p < .0001). Moderator analysis revealed exercise energy expenditure significantly moderated the effect of prior exercise on the total TG response (p < .0001). Exercise modality (e.g., cardiovascular, resistance, combination of both cardiovascular and resistance, or standing), cardiovascular exercise type (e.g., continuous, interval, concurrent, or combined), and timing of exercise prior to meal administration significantly affected the total TG response (p < .001). Additionally, exercise had a moderate effect on the incremental area under the curve TG response (Cohen's d = -0.40; p < .0001). The current analysis reveals a more homogeneous data set than previously reported. The attenuation of postprandial TG appears largely dependent on exercise energy expenditure (∼2 MJ) and the timing of exercise. The effect of prior exercise on the postprandial TG response appears to be transient; therefore, exercise should be frequent to elicit an adaptation.

Exercise to lower postprandial lipemia: why, when, what and how

We review recent findings on the ability of exercise to lower postprandial lipemia (PPL). Specifically, we answer why exercise is important in lowering PPL, when it is most effective to exercise to achieve this, what the preferred exercise is and how exercise reduces PPL. Most findings confirm the power of exercise to lower PPL, which is an independent risk factor for cardiovascular disease. Exercise is most effective when performed on the day preceding a high- or moderate-fat meal. This effect lasts up to approximately two days; therefore, one should exercise frequently to maintain this benefit. However, the time of exercise relative to a meal is not that important in real-life conditions, since one consumes several meals during the day; thus, an exercise bout will inevitably exert its lowering effect on PPL in one or more of the subsequent meals. Although moderate-intensity continuous exercise, high-intensity intermittent exercise (HIIE), resistance exercise and accumulation of short bouts of exercise throughout the day are all effective in lowering PPL, submaximal, high-volume interval exercise seems to be superior, provided it is tolerable. Finally, exercise reduces PPL by both lowering the rate of appearance and increasing the clearance of triacylglycerol-rich lipoproteins from the circulation.

Prior arm crank exercise has no effect on postprandial lipaemia in non-disabled adults

A single bout of cycling or running performed in the evening can reduce postprandial lipaemia (PPL) the following morning, although this is currently unknown for upper-body exercise. The aim of this study was to determine if a bout of arm crank exercise (high-intensity interval [HIIE] or moderate-intensity continuous [MICE]), can attenuate PPL in non-injured individuals. Eleven healthy and recreationally active participants (eight males, three females; age: 27 ± 7 yr; body mass index: 23.5 ± 2.5 kg · m-2) volunteered to participate in three trials: HIIE (10 x 60 s at 80% peak power output), MICE (50% peak power output of isocaloric duration), and a no-exercise control condition. Each exercise bout was performed at 18:00, and participants consumed a standardized evening meal at 20:00. Following an overnight fast, a 5-h mixed-macronutrient tolerance test was performed at 08:00. There were no significant differences in triglyceride incremental area under the curve between HIIE (192 ± 94 mmol. L-1 per 300 min), MICE (184 ± 111 mmol. L-1 per 300 min), and the no-exercise condition (175 ± 90 mmol. L-1 per 300 min) (P=0.46). There were no significant differences in incremental area under the curve for glucose (P=0.91) or insulin (P=0.59) between conditions. Upper-body MICE and HIIE performed in the evening do not influence PPL the following morning, in normotriglyceridemic individuals. Clinical Trials Registration: NCT04277091 Novelty: • Arm crank exercise has no effect on PPL when performed the evening prior to a mixed-macronutrient meal test • Upper-body sprint interval exercise should be investigated as a potential solution to reduce PPL.