The Effect of a Single Bout of Continuous Aerobic Exercise on Glucose, Insulin and Glucagon Concentrations Compared to Resting Conditions in Healthy Adults: A Systematic Review, Meta-Analysis and Meta-Regression

Health Promotion and Chronic Disease Prevention at the Workplace

The concept of workplace safety and health has focused largely on preventing accidents and on minimizing hazardous exposures. However, because workers spend a substantial part of their waking hours at the workplace, the potential to influence the health of a large proportion of the world's population through the workplace is enormous. The opportunities to carry out health promotion and chronic disease prevention activities at the workplace are countless, including (a) health screening; (b) tobacco cessation activities; (c) the promotion of healthy food choices and weight loss; (d) active breaks with physical exercise in terms of microexercise, enhancement of infrastructure to stimulate physical activity, and organization of work tasks to facilitate incidental physical activity; and (e) routine vaccinations. This review discusses the key factors necessary to implement health promotion and chronic disease prevention programs at the workplace (SWOLE model) and discusses the different foci and possibilities with respect to the differing nature of work for the blue- versus white-collar workforce.

Effects of acute and chronic stair-climbing exercise on metabolic health: A systematic review

Stair climbing exercise (SE) provides a feasible approach to elevate physical activity, but the effects on metabolic health are unclear. We systematically reviewed the currently available evidence on the effects of SE on fasting and postprandial glycaemia and lipidaemia. Studies were included if they investigated the effects of acute or chronic (at least 2 weeks) SE on fasting and/or postprandial glycaemic (insulin and glucose) and lipidaemic (triacylglycerols and non-esterified fatty acids) responses in healthy, prediabetic or type 2 diabetic adult populations. PubMed, Web of Science and Scopus were searched for eligible studies until July 2022. A total of 25 studies (14 acute and 11 chronic) were eligible for review. Acute bout(s) of SE can reduce postprandial glycaemia in individuals with prediabetes and type 2 diabetes (8 of 9 studies), but not in normoglycemic individuals. The effects of acute SE on postprandial lipidaemic responses and SE training on both fasting and postprandial glycaemia/lipidaemia were unclear. Acute SE may reduce postprandial glucose concentrations in people with impaired glycaemic control, but high-quality studies are needed. More studies are needed to determine the effect of chronic SE training on postprandial glucose and lipid responses, and the acute effects of SE on lipid responses.

Are There Interindividual Responses of Cardiovascular Disease Risk Markers to Acute Exercise? A Replicate Crossover Trial

PURPOSE

Using a replicated crossover design, we quantified the response heterogeneity of postprandial cardiovascular disease risk marker responses to acute exercise.

METHODS

Twenty men (mean (SD) age, 26 (6) yr; body mass index, 23.9 (2.4) kg·m -2 ) completed four 2-d conditions (two control, two exercise) in randomized orders. On days 1 and 2, participants rested and consumed two high-fat meals over 9 h. Participants ran for 60 min (61 (7)% of peak oxygen uptake) on day 1 (6.5 to 7.5 h) of both exercise conditions. Time-averaged total area under the curve (TAUC) for triacylglycerol, glucose, and insulin were calculated from 11 venous blood samples on day 2. Arterial stiffness and blood pressure responses were calculated from measurements at baseline on day 1 and at 2.5 h on day 2. Consistency of individual differences was explored by correlating the two replicates of control-adjusted exercise responses for each outcome. Within-participant covariate-adjusted linear mixed models quantified participant-by-condition interactions and individual response SDs.

RESULTS

Acute exercise reduced mean TAUC-triacylglycerol (-0.27 mmol·L -1 ·h; Cohen's d = 0.29, P = 0.017) and TAUC-insulin (-25 pmol·L -1 ·h; Cohen's d = 0.35, P = 0.022) versus control, but led to negligible changes in TAUC-glucose and the vascular outcomes (Cohen's d ≤ 0.36, P ≥ 0.106). Small-to-moderate, but nonsignificant, correlations were observed between the two response replicates ( r = -0.42 to 0.15, P ≥ 0.066). We did not detect any individual response heterogeneity. All participant-by-condition interactions were P ≥ 0.137, and all individual response SDs were small with wide 95% confidence intervals overlapping zero.

CONCLUSIONS

Large trial-to-trial within-subject variability inhibited detection of consistent interindividual variability in postprandial metabolic and vascular responses to acute exercise.

The Synergistic Effect of Quince Fruit and Probiotics (Lactobacillus and Bifidobacterium) on Reducing Oxidative Stress and Inflammation at the Intestinal Level and Improving Athletic Performance during Endurance Exercise

Endurance exercise promotes damage at the intestinal level and generates a variety of symptoms related to oxidative stress processes, inflammatory processes, microbiota dysbiosis, and intestinal barrier damage. This study evaluated the effects of quince (Cydonia oblonga Mill.) and probiotics of the genera Lactobacillus and Bifidobacterium on intestinal protection and exercise endurance in an animal swimming model. Phytochemical characterization of the quince fruit demonstrated a total dietary fiber concentration of 0.820 ± 0.70 g/100 g and a fiber-bound phenolic content of 30,218 ± 104 µg/g in the freeze-dried fruit. UPLC-PDA-ESI-QqQ analyses identified a high content of polyphenol, mainly flavanols, hydroxycinnamic acids, hydroxybenzoic acids, flavonols, and, to a lesser extent, dihydrochalcones. The animal model of swimming was performed using C57BL/6 mice. The histological results determined that the consumption of the synbiotic generated intestinal protection and increased antioxidant (catalase and glutathione peroxidase enzymes) and anti-inflammatory (TNF-α and IL-6 and increasing IL-10) activities. An immunohistochemical analysis indicated mitochondrial biogenesis (Tom2) at the muscular level related to the increased swimming performance. These effects correlated mainly with the polyphenol content of the fruit and the effect of the probiotics. Therefore, this combination of quince and probiotics could be an alternative for the generation of a synbiotic product that improves exercise endurance and reduces the effects generated by the practice of high performance sports.

Influence of body composition and cardiorespiratory fitness on plasma HSP72, norepinephrine, insulin, and glucose responses to an acute aerobic exercise bout performed in the fed state

Being overweight is already considered a metabolic risk factor, which can be overcome by increasing cardiorespiratory fitness (CRF). Acute exercise is known to induce changes in plasma hormones and heat shock proteins release. However, there is a lack of studies investigating the impact of body composition and CRF on these variables following acute aerobic exercise. To assess the influence of body composition and cardiorespiratory fitness on plasma heat shock protein 72 kDa (HSP72), norepinephrine (NE), insulin, and glucose responses to an acute aerobic exercise bout in the fed state. Twenty-four healthy male adults were recruited and allocated into three groups: overweight sedentary (n = 8), normal weight sedentary (n = 8), and normal weight active (n = 8). The volunteers performed an acute moderate exercise session on a treadmill at 70% of VO2 peak. Blood samples were drawn at baseline, immediately post-exercise, and at 1-h post-exercise. The exercise session did not induce changes in HSP72 nor NE but changes in glucose and insulin were affected by body mass index. Also, subjects with elevated CRF maintain reduced NE through exercise. At baseline, the overweight sedentary group showed elevated NE, insulin, and glucose; these last two impacting the HOMA-IR index. Thirty minutes of aerobic exercise at 70% VO2 peak, in the fed state, did not change the levels of plasma NE and HSP72. Elevated body composition seems to impact metabolic profile and increase sympathetic activity. Conversely, subjects with increased cardiorespiratory fitness seem to have attenuated sympathetic activity.

The metabolic interplay between dietary carbohydrate and exercise and its role in acute appetite regulation in males: a randomized controlled study

An understanding of the metabolic determinants of postexercise appetite regulation would facilitate development of adjunctive therapeutics to suppress compensatory eating behaviours and improve the efficacy of exercise as a weight-loss treatment. Metabolic responses to acute exercise are, however, dependent on pre-exercise nutritional practices, including carbohydrate intake. We therefore aimed to determine the interactive effects of dietary carbohydrate and exercise on plasma hormonal and metabolite responses and explore mediators of exercise-induced changes in appetite regulation across nutritional states. In this randomized crossover study, participants completed four 120 min visits: (i) control (water) followed by rest; (ii) control followed by exercise (30 min at ∼75% of maximal oxygen uptake); (iii) carbohydrate (75 g maltodextrin) followed by rest; and (iv) carbohydrate followed by exercise. An ad libitum meal was provided at the end of each 120 min visit, with blood sample collection and appetite assessment performed at predefined intervals. We found that dietary carbohydrate and exercise exerted independent effects on the hormones glucagon-like peptide 1 (carbohydrate, 16.8 pmol/L; exercise, 7.4 pmol/L), ghrelin (carbohydrate, -48.8 pmol/L; exercise: -22.7 pmol/L) and glucagon (carbohydrate, 9.8 ng/L; exercise, 8.2 ng/L) that were linked to the generation of distinct plasma 1 H nuclear magnetic resonance metabolic phenotypes. These metabolic responses were associated with changes in appetite and energy intake, and plasma acetate and succinate were subsequently identified as potential novel mediators of exercise-induced appetite and energy intake responses. In summary, dietary carbohydrate and exercise independently influence gastrointestinal hormones associated with appetite regulation. Future work is warranted to probe the mechanistic importance of plasma acetate and succinate in postexercise appetite regulation. KEY POINTS: Carbohydrate and exercise independently influence key appetite-regulating hormones. Temporal changes in postexercise appetite are linked to acetate, lactate and peptide YY. Postexercise energy intake is associated with glucagon-like peptide 1 and succinate levels.

The molecular pharmacology of glucagon agonists in diabetes and obesity

Within recent decades glucagon receptor (GcgR) agonism has drawn attention as a therapeutic tool for the treatment of type 2 diabetes and obesity. In both mice and humans, glucagon administration enhances energy expenditure and suppresses food intake suggesting a promising metabolic utility. Therefore synthetic optimization of glucagon-based pharmacology to further resolve the physiological and cellular underpinnings mediating these effects has advanced. Chemical modifications to the glucagon sequence have allowed for greater peptide solubility, stability, circulating half-life, and understanding of the structure-function potential behind partial and "super"-agonists. The knowledge gained from such modifications has provided a basis for the development of long-acting glucagon analogues, chimeric unimolecular dual- and tri-agonists, and novel strategies for nuclear hormone targeting into glucagon receptor-expressing tissues. In this review, we summarize the developments leading toward the current advanced state of glucagon-based pharmacology, while highlighting the associated biological and therapeutic effects in the context of diabetes and obesity.

Comparative effectiveness of playing golf to Nordic walking and walking on acute physiological effects on cardiometabolic markers in healthy older adults: a randomised cross-over study

Objectives

The acute effects of aerobic exercise on cardiometabolic markers are well documented in younger healthy individuals, but the same effects in older adults have not been elucidated. As such, this study compares the acute effects of three different types of age-appropriate aerobic exercises on cardiometabolic markers.

Methods

Healthy older golfers (n=25, 16 male and 9 female, 68±4 years) were enrolled in a randomised cross-over experiment. We compared the effects of three different acute aerobic exercises (18-hole golf, 6 km Nordic walk, 6 km walk) on blood pressure, blood glucose and blood lipid profile in a real-life environment.

Results

In the between-group comparison, playing golf resulted in a difference in blood glucose (golf: 0.01±1.0 mmol/L, walk: 1.3±0.9 mmol/L, p<0.001) compared with walking and triglycerides (golf: 0.13±0.2 mmol/L, Nordic walk: 0.31±0.2 mmol/L, walk: 0.23±0.2 mmol, p=0.012) and high-density lipoprotein cholesterol (golf: 0.04±0.06 mmol/L, Nordic walk: -0.02±0.06 mmol/L, walk: -0.02±0.07 mmol/L, p=0.002) compared with Nordic walking and walking. In addition, all groups had significant decreases (p<0.001) in systolic blood pressure, and Nordic walking and walking also demonstrated a decrease in diastolic blood pressure (p<0.05).

Conclusion

Acute bouts of aerobic exercise improved cardiovascular profile in healthy older adults. Despite the lower exercise intensity of golf, the longer duration and higher energy expenditure appeared to have a more positive effect on lipid profile and glucose metabolism compared with Nordic walking and walking.

Trial registration number

ISRCTN10007294.

Effect of Pre-Meal Metformin With or Without an Acute Exercise Bout on Postprandial Lipemic and Glycemic Responses in Metabolic Syndrome Patients: A Randomized, Open Label, Crossover Study

INTRODUCTION

Both exercise and pre-meal metformin could lower postprandial glucose and lipid profiles.

AIMS

To explore whether pre-meal metformin administration is superior to metformin administration with the meal in reducing postprandial lipid and glucose metabolism, and whether its combination with exercise confer superior benefits in metabolic syndrome patients.

MATERIALS AND METHODS

In a randomized crossover design, 15 metabolic syndrome patients were assigned to 6 sequences including 3 experimental conditions: metformin administration with a test meal (met-meal), metformin administration 30 min prior to a test meal (pre-meal-met) with or without an exercise bout designed to expend 700 Kcal at 60% VO₂ peak performed the evening just before pre-meal-met condition. Only 13 participants (3 males, 10 females; age: 46 ± 9.86, HbA1c: 6.23 ± 0.36) were included in the final analysis.

RESULTS

Postprandial triglyceridemia was unaffected by any condition (all P > .05). However, both pre-meal-met (-7.1%, P = .009) and pre-meal-metx (-8.2%, P = .013) significantly reduced total cholesterol AUC with no significant differences between the two latter condition (P = .616). Similarly, LDL-cholesterol levels were significantly lower during both pre-meal-met (-10.1%, P = .013) and pre-meal-metx (-10.7%, P = .021) compared to met-meal with no difference between latter conditions (P = .822). Plasma glucose AUC was significantly reduced by pre-meal-metx compared to both pre-meal-met (-7.5%, P = .045) and met-meal (-8%, P = .03). Insulin AUC was significantly lower during pre-meal-metx compared to met-meal (-36.4%, P = .044).

CONCLUSIONS

Metformin administration 30 minutes prior to meal seems to exert favorable effects on postprandial TC and LDL-Cholesterol levels compared to its administration with meal. Addition of one exercise bout only improved postprandial glycemia and insulinemia.

TRIAL REGISTRY

Pan African clinical trial registry, Identifier PACTR202203690920424.

INFLUENCE OF AEROBIC AND ANAEROBIC SPORTS ON THE TRAINING EFFECTS OF TABLE TENNIS PLAYERS

ABSTRACT Introduction The weakness of cadence and rotation speed in table tennis brings new challenges to the physical strength of young players, presenting a redoubled effort for physical fitness and stability of the shot movements. Objective Study the influence of aerobic and anaerobic exercise on the training effect of table tennis players. Methods 27 young table tennis players aged 9-17 years old from China Table Tennis Institute were selected as the experimental objects. They were divided into 14 in the experimental group for 12 weeks of core strength training and 13 in the control group for 12 weeks of routine physical training. Results There was no significant difference in the control group before and after the experiment (P > 0.05); there was no significant difference in core strength between the experimental group and the control group before the experiment (P > 0.05). Conclusion After the experiment, the core strength of both groups of young table tennis players improved, and the core strength of the experimental group improved significantly from the fourth level to the fifth level of body posture table maintenance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

The acute effect of glucagon on components of energy balance and glucose homoeostasis in adults without diabetes: a systematic review and meta-analysis

Objective

Using a systematic review and meta-analysis, we aimed to estimate the mean effect of acute glucagon administration on components of energy balance and glucose homoeostasis in adults without diabetes.

Methods

CENTRAL, CINAHL, Embase, MEDLINE, PubMed, and Scopus databases were searched from inception to May 2021. To be included, papers had to be a randomised, crossover, single- or double-blind study, measuring ad libitum meal energy intake, energy expenditure, subjective appetite, glucose, and/or insulin following acute administration of glucagon and an appropriate comparator in adults without diabetes. Risk of bias was assessed using the Revised Cochrane Risk of Bias Tool for Randomized trials with additional considerations for cross-over trials. Certainty of evidence was assessed using the GRADE approach. Random-effect meta-analyses were performed for outcomes with at least five studies. This study is registered on PROSPERO (CRD42021269623).

Results

In total, 13 papers (15 studies) were considered eligible: energy intake (5 studies, 77 participants); energy expenditure (5 studies, 59 participants); subjective appetite (3 studies, 39 participants); glucose (13 studies, 159 participants); insulin (12 studies, 147 participants). All studies had some concerns with regards to risk of bias. Mean intervention effect of acute glucagon administration on energy intake was small (standardised mean difference [SMD]: –0.19; 95% CI, –0.59 to 0.21; P = 0.345). Mean intervention effect of acute glucagon administration on energy expenditure (SMD: 0.72; 95% CI, 0.37–1.08; P < 0.001), glucose (SMD: 1.11; 95% CI, 0.60–1.62; P < 0.001), and insulin (SMD: 1.33; 95% CI, 0.88–1.77; P < 0.001) was moderate to large.

Conclusions

Acute glucagon administration produces substantial increases in energy expenditure, and in circulating insulin and glucose concentrations. However, the effect of acute glucagon administration on energy intake is unclear. Insufficient evidence was available to evaluate the acute effect of glucagon on subjective appetite.

Whey protein improves glycemia during an oral glucose tolerance test compared to vigorous-intensity aerobic exercise in young adult men

BACKGROUND

Both aerobic exercise and whey protein can improve glucose regulation. The purpose of this study was to investigate how a single bout of vigorous-intensity aerobic exercise and whey protein, independently, as well as when combined, influence glycemia during an oral glucose tolerance test in sedentary, young men.

METHODS

Healthy males (n = 11) completed four randomized trials: no exercise/no whey protein (R); exercise (EX; walking at 70% VO2max for 60 min); 50 g of whey protein (W); and exercise combined with 50 g of whey protein (EXW). Each trial included a 75 g oral glucose tolerance test (OGTT) that was completed after an overnight fast. Blood samples were collected over a two-hour period during the OGTT. For EX and EXW, the exercise was performed the evening before the OGTT and the 50 g of whey protein was dissolved in 250 mL of water and was consumed as a preload 30 min prior to the OGTT. For R and EX, participants consumed 250 mL of water prior to the OGTT. Plasma samples were analyzed for glucose, insulin, C-peptide, glucagon, gastric inhibitory peptide (GIP) and glucagon like peptide 1 (GLP-1), and postprandial incremental area under the curve (iAUC) was calculated for each.

RESULTS

Glucose iAUC was reduced during W (- 32.9 ± 22.3 mmol/L) compared to R (122.7 ± 29.8 mmol/L; p < 0.01) and EX (154.3 ± 29.2 mmol/L; p < 0.01). Similarly, glucose iAUC was reduced for EXW (17.4 ± 28.9 mmol/L) compared to R and EX (p < 0.01 for both). There were no differences in iAUC for insulin, C-peptide, GIP, GLP-1, and glucagon between the four trials. Insulin, C-peptide, glucagon, GIP, and GLP-1 were elevated during the whey protein preload period for W and EXW compared to EX and R (p < 0.01). There were no differences for insulin, C-peptide, glucagon, GIP, or GLP-1 between trials for the remaining duration of the OGTT.

CONCLUSIONS

Glucose responses during an oral glucose tolerance test were improved for W compared to EX. There were no additional improvements in glucose responses when vigorous-intensity aerobic exercise was combined with whey protein (EXW).

Urinary extracellular vesicle as a potential biomarker of exercise-induced fatigue in young adult males

Purpose

Previous studies have suggested that circulating extracellular vesicles (EVs) arise after high intensity exercise and urine could reflect the plasma proteome. Herein, we investigated the characteristic of urinary EVs from healthy young adult males who had completed a maximal effort exercise test.

Methods

Thirteen healthy men completed a 20 m shuttle run test (20 m SRT). Fresh urine samples were collected at first morning, right after, and 1 h rest after 20 m SRT. Also, blood lactate, heart rate, rating of perceived exertion, and blood pressure were measured before, right after, and 1 h rest after 20 m SRT. Urinary EVs were analyzed using Exoview instrument and microRNAs (miRNAs) sequencing on urinary EVs were performed.

Results

Urinary EVs increased significantly after exercise and returned to baseline value after 1 h of rest. miRNA sequencing on urinary EV revealed alterations in four miRNAs (1 up and 3 down) and nine miRNAs (2 up and 7 down) in pre- vs. post- and post- vs. post-1 h samples, respectively. Lastly, bioinformatic analysis of urinary EV miRNA suggests that predicted target genes could affect PI3K-Akt, mitogen-activated protein kinase, and insulin pathways by exercise.

Conclusions

Exercise to voluntary exhaustion increased the number of EVs in urine. Also, miRNAs in urinary EVs were altered after exercise. These findings could indicate the possibility of using the urinary EVs as a novel biomarker of acute exercise-induced fatigue.

Maintenance of plasma glucose variability after an acute session of aerobic exercise despite changes in insulin and glucagon-like peptide-1 levels in type 2 diabetes

Objective

The present study aimed to evaluate glucose variability and hormonal responses during and after an aerobic exercise session performed after breakfast in type 2 diabetes patients treated with metformin.

Methods

In this quasi-experimental study individuals underwent clinical and laboratory evaluations and maximal exercise test. After two weeks an aerobic exercise session (30 minutes at 60%-70% of the peak heart rate) was performed. At rest, during and after the exercise session, glucose variability (mean amplitude glucose excursions, glucose coefficient of variation, and glucose standard deviation) and levels of plasma glucose, insulin, glucagon, and glucagon-like-peptide-1 were evaluated.

Results

Thirteen patients were enrolled in the study. Plasma glucose increased at 15 minutes during the exercise session (244.6 ± 61.9 mg/dL), and decreased at 60 min after exercise (195.6 ± 50.0 mg/dL). Glucose variability did not show any difference before and after exercise. Insulin levels at 15 min [27.1 μU/mL (14.2-42.1)] and 30 min [26.3 μU/mL (14.6-37.4)] during the exercise were higher than those at fasting [11.2 μU/mL (6.7-14.9)] but decreased 60 minutes after exercise (90 minutes) [16.6 μU/mL (8.7-31.7)]. Glucagon levels did not show any difference. GLP-1 levels increased at 30 min [7.9 pmol/L (7.1-9.2)] during exercise and decreased 60 min after exercise (90 minutes) [7.7 pmol/L (6.8-8.5)].

Conclusion

Subjects with type 2 diabetes presented expected changes in insulin, glucagon and GLP-1 levels after breakfast and a single aerobic exercise session, not accompanied by glycemic variability changes.

Effect of aerobic exercise as a treatment on type 2 diabetes mellitus with depression-like behavior zebrafish

BACKGROUND

Depression is the most known complication of type 2 diabetes mellitus (T2DM). Aerobic exercise improves glycemic control in T2DM, although the underlying mechanisms of comorbid depression-like behaviors in T2DM have not yet been fully elucidated.

METHODS

120 zebrafish were randomly assigned to four groups: Control, T2DM, T2DM + metformin, and T2DM + aerobic exercise. Then, all animals except the control group were fed with high glucose fairy shrimp (~40 g/kg/day) and exposed reserpine (40 μg/ml for 20 min) for 10 days. Here, behavioral tests were used for model verification. Following the verification, all groups were treated as before. Additionally, the T2DM + metformin group received metformin (~10.6 mg/kg/day) at the same time, while the T2DM + aerobic exercise group received aerobic exercise 30 min/day. Finally, blood glucose and behavioral tests, as well as protein and molecular levels were determined at Day 11 and 12.

RESULTS

Aerobic exercise alleviated depressive-like behavior and enhanced the levels of antidepressant biomarkers (NE, 5-HIAA) in zebrafish after 10 consecutive days of exercise. Additionally, 10 consecutive days of aerobic exercise decreased the levels of inflammatory biomarkers (IFN-γ, IL-1, IL-4) and depressive biomarkers (cortisol). Meanwhile, it also aided in the reduction of CD11b, IL-6, IL-6R, and caspase-3 expression to combat the neuroinflammation induced by T2DM, mediated the BDNF-TrkB pathway, and increased Bcl-2/Bax levels.

CONCLUSION

Given the remarkable similarity in neurochemistry between humans and zebrafish, this study supports the effectiveness of aerobic exercise as clinical guidance in preventing and treating T2DM complicated with depression.