The effect of consuming low- versus high-glycemic index meals after exercise on postprandial blood lipid response following a next-day high-fat meal

Effect of sleep restriction, with or without prior evening exercise, on morning postprandial lipemia

Sleep restriction (SR) impairs postprandial glycemia following a high-glucose challenge and exercise improves it, but their combined impact on postprandial lipemia in response to a high-fat challenge remains unknown. This project investigated whether one night of SR impairs morning postprandial lipemia and if prior evening exercise influences the response. We hypothesized SR would induce an exaggerated postprandial lipemic response to a high-fat morning challenge and that prior evening exercise would fully or partially ameliorate these impairments. In 10 sedentary individuals with overweight or obesity (females: 4, age: 28.1 ± 3.8 years, body mass index: 30.4 ± 2.2 kg/m2), we compared the effects of one night of SR (4 h) to normal sleep (8 h), with and without prior moderate-intensity aerobic exercise (45 min, 65% VO2max), on postprandial lipemia and satiety following a standardized high-fat morning challenge (4 h). Spline regression was used to compare differences in the time course of the blood-based outcomes between exercise and sleep conditions. No significant differences were observed in fasting or 2 h concentrations of glucose, insulin, non-esterified fatty acids, or triglyceride, areas under the curves, indexes of metabolism, or satiety between conditions. However, exercise had an interaction between the spline term and exercise and sleep conditions (p < 0.001) for glucose, insulin, non-esterified fatty acids, and triglycerides during the high-fat challenge. The findings indicate that one night of SR has minimal effects on morning postprandial lipemia, irrespective of previous aerobic exercise. Notably, exercise reduced triglyceride concentrations in the latter half of the testing period, although this effect was abolished during SR conditions. Clinical trial #: NCT05713370.

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.

Benefits of a plant-based diet and considerations for the athlete

Individuals may opt to follow a plant-based diet for a variety of reasons, such as religious practices, health benefits or concerns for animal or environmental welfare. Such diets offer a broad spectrum of health benefits including aiding in the prevention and management of chronic diseases. In addition to health benefits, a plant-based diet may provide performance-enhancing effects for various types of exercise due to high carbohydrate levels and the high concentration of antioxidants and phytochemicals found in a plant-based diet. However, some plant-based foods also contain anti-nutrional factors, such as phytate and tannins, which decrease the bioavailability of key nutrients, such as iron, zinc, and protein. Thus, plant-based diets must be carefully planned to ensure adequate intake and absorption of energy and all essential nutrients. The current narrative review summarizes the current state of the research concerning the implications of a plant-based diet for health and exercise performance. It also outlines strategies to enhance the bioavailability of nutrients, sources of hard-to-get nutrients, and sport supplements that could interest plant-based athletes.

Skim milk as a recovery beverage after exercise is superior to a sports drink for reducing next-day postprandial blood glucose and increasing postprandial fat oxidation

We determined the effect of consuming low-glycemic index (LGI) skim milk compared to a high-glycemic index (HGI) sports drink following evening exercise on fat oxidation and blood lipids after a subsequent high-energy breakfast. We hypothesized that postexercise skim milk consumption, compared to sports drink, would increase fat oxidation and lower harmful blood lipid and glucose concentrations after a next-day high-energy breakfast. In this randomized counterbalanced crossover trial, 20 overweight-obese participants (body mass index ≥ 25 kg/m²) underwent 4 conditions: 90-minute exercise (50% Vo_2peak) followed by sports drink (EX-HGI), exercise followed by isoenergetic skim milk (EX-LGI), exercise followed by water (Exercise), and a control condition (Control). The amount of the sports drink or milk consumed postexercise was based on the energy used during exercise plus 10%. Blood lipids, glucose, and fat oxidation were assessed before and for 6 hours after a high-energy breakfast the next morning. Fat oxidation was highest for EX-LGI (6.7 ± 2.7 g/h) and lowest for EX-HGI (6.0 ± 1.8 g/h) (condition main effect; P = .042). Triglyceride concentration and total area under the curve were higher with EX-HGI than Exercise (1.7 ± 1.6 vs 1.3 ± 1.0 mmol/L, P = .037, and 11.7 ± 9.4 vs 8.6 ± 6.0 mmol L^-1 h, P = .005, respectively). Glucose concentration was lower with EX-LGI than EX-HGI (4.1 ± 1.1 vs 4.4 ± 1.1 mmol/L, P = .027). Homeostatic model assessment of insulin resistance was higher with EX-HGI than Control (2.32 ± 1.15 vs 1.86 ± 0.97, P = .005). In conclusion, evening postexercise skim milk consumption, compared with a high-GI sports drink, significantly reduced blood glucose and possibly increased fat oxidation after a high-energy breakfast the next morning.

Acute exercise effects on postprandial fat oxidation: meta-analysis and systematic review

The purpose of this systematic review was to synthesize and evaluate current literature examining the effects of exercise on postprandial fat oxidation, as well as to provide future direction. A quantitative review was performed using meta-analytic methods. A moderator analysis was performed to investigate potential variables that could influence the effect of exercise on postprandial fat oxidation. Fifty-six effects from 26 studies were retrieved. There was a moderate effect of exercise on postprandial fat oxidation (Cohen's d = 0.58 (95% CI, 0.39 to 0.78)). Moderator analysis revealed that sex, age, weight status, training status, exercise type, exercise intensity, timing of exercise, and composition of the meal challenge significantly affected the impact of prior exercise on postprandial fat oxidation. The moderator analysis also indicated that most previous studies have investigated the impact of prior moderate-intensity endurance exercise on postprandial fat oxidation in young, healthy, lean men. Suggested priorities for future research in this area include (i) an examination of sex differences in and/or female-specific aspects of postprandial metabolism; (ii) a comprehensive evaluation of exercise modalities, intensities, and durations; and (iii) a wider variety of test meal compositions, especially those with higher fat content. Novelty A systematic review of the impact of exercise on postprandial fat oxidation was performed using meta-analytic methods. Analysis revealed a moderate effect of exercise on postprandial fat oxidation. The presented data support a need for future studies to investigate sex differences and to include comprehensive evaluations of exercise modalities, intensities, and duration.

The Effect of a Low Glycemic Index Pulse-Based Diet on Insulin Sensitivity, Insulin Resistance, Bone Resorption and Cardiovascular Risk Factors during Bed Rest

We determined the effects of a low glycemic-index pulse-based diet (i.e., containing lentils, chick peas, beans, and split peas) compared to a typical hospital diet on insulin sensitivity assessed by the Matsuda index from the insulin and glucose response to a two-hour oral glucose tolerance test, insulin resistance assessed by the homeostatic model assessment of insulin resistance (HOMA-IR), bone resorption assessed by 24 h excretion of urinary n-telopeptides(Ntx) and cardiovascular risk factors (blood lipids, blood pressure, arterial stiffness and heart rate variability) during bed rest. Using a randomized, counter-balanced cross-over design with one-month washout, six healthy individuals (30 ± 12 years) consumed the diets during four days of bed rest. The Matsuda index, HOMA-IR, urinary Ntx and cardiovascular risk factors were determined at baseline and after the last day of bed rest. Compared to the typical hospital diet, the pulse-based diet improved the Matsuda index (indicating increased insulin sensitivity; baseline to post-bed rest: 6.54 ± 1.94 to 6.39 ± 2.71 hospital diet vs. 7.14 ± 2.36 to 8.75 ± 3.13 pulse-based diet; p = 0.017), decreased HOMA-IR (1.38 ± 0.54 to 1.37 ± 0.50 hospital diet vs. 1.48 ± 0.54 to 0.88 ± 0.37 pulse-based diet; p = 0.022), and attenuated the increase in Ntx (+89 ± 75% hospital diet vs. +33 ± 20% pulse-based diet; p = 0.035). No differences for changes in cardiovascular risk factors were found between the two diet conditions, with the exception of decreased diastolic blood pressure during day three of bed rest in the pulse-based versus hospital diet (61 ± 9 vs. 66 ± 7 mmHg; p = 0.03). A pulse-based diet was superior to a hospital diet for maintaining insulin sensitivity, preventing insulin resistance, attenuating bone resorption and decreasing diastolic blood pressure during four days of bed rest.

Acute metabolic responses following different resistance exercise protocols

Resistance exercise (RE) can be an excellent modality for glycemic control. Studies have demonstrated that a single RE session can reduce glycemia in subjects with or without diabetes. Little is known about the dose–response effect of RE on glycemic control. This study aimed to investigate the acute metabolic responses after different RE protocols. Eighty-nine males were separated into six groups that completed RE protocols: 2 sets of 18 repetitions (2 × 18 at 50% of 1-repetition maximum (1RM); n = 19); 3 sets of 12 repetitions (3 × 12 at 70% of 1RM; n = 14); 4 sets of 9 repetitions (4 × 9 at 80% of 1RM; n = 13); 6 sets of 6 repetitions (6 × 6 at 90% of 1RM; n = 19); circuit (2 × 18 at 50% of 1RM; n = 12); and a control session (n = 12). The exercise sequence consisted of 8 exercises. An oral glucose tolerance test was conducted with metabolic measurements immediately after each RE protocol and every 15 min until 120 min of recovery. All groups exhibited significantly lower values (p < 0.05) in the glucose area under the curve (AUC) when compared with control over a 120 min monitoring period. The 6 × 6 group showed a significantly lower glucose AUC versus the 3 × 12 and 4 × 9 groups (p = 0.004; p = 0.001, respectively). As for blood lactate, the control and 6 × 6 groups exhibited lower AUC values versus all other groups (p < 0.05), and AUC for glucose and lactate concentration showed a negative and significant correlation (r = –0.46; p < 0.0001). It appears that a combination of 9–12 repetitions per set and 3–4 sets per muscle group might be optimal for acute postprandial glucose control.

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.