Positive effect of exercise training at maximal fat oxidation intensity on body composition and lipid metabolism in overweight middle-aged women

Toward Exercise Guidelines for Optimizing Fat Oxidation During Exercise in Obesity: A Systematic Review and Meta-Regression

BACKGROUND

Exercise training performed at maximal fat oxidation (FATmax) is an efficient non-pharmacological approach for the management of obesity and its related cardio-metabolic disorders.

OBJECTIVES

Therefore, this work aimed to provide exercise intensity guidelines and training volume recommendations for maximizing fat oxidation in patients with obesity.

METHODS

A systematic review of original articles published in English, Spanish or French languages was carried out in EBSCOhost, PubMed and Scopus by strictly following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Those studies that analyzed maximal fat oxidation (MFO) and FATmax in patients with obesity (body fat > 25% for men; > 35% for women) by calculating substrate oxidation rates through indirect calorimetry during a graded exercise test with short-duration stages (< 10 min) were selected for quantitative analysis. The accuracy of relative oxygen uptake (% peak oxygen uptake [%[Formula: see text]O2peak]) and relative heart rate (% peak heart rate [%HRpeak]) for establishing FATmax reference values was investigated by analyzing their intra-individual and inter-study variation. Moreover, cluster analysis and meta-regression were used for determining the influence of biological factors and methodological procedures on MFO and FATmax.

RESULTS

Sixty-four manuscripts were selected from 146 records; 23 studies only recruited men (n = 465), 14 studies only evaluated women (n = 575), and 27 studies included individuals from both sexes (n = 6434). The majority of the evaluated subjects were middle-aged adults (aged 40-60 y; 84%) with a poor cardiorespiratory fitness (≤ 43 mL·kg-1·min-1; 81%), and the reported MFO ranged from 0.27 to 0.33 g·min-1. The relative heart rate at FATmax (coefficient of variation [CV]: 8.8%) showed a lower intra-individual variation compared with relative oxygen uptake (CV: 17.2%). Furthermore, blood lactate levels at FATmax ranged from 1.3 to 2.7 mmol·L-1 while the speed and power output at FATmax fluctuated from 4 to 5.1 km·h-1 and 42.8-60.2 watts, respectively. Age, body mass index, cardiorespiratory fitness, FATmax, the type of ergometer and the stoichiometric equation used to calculate the MFO independently explained MFO values (R2 = 0.85; p < 0.01). The MFO in adolescents was superior in comparison with MFO observed in young and middle-aged adults. On the other hand, the MFO was higher during treadmill walking in comparison with stationary cycling. Body fat and MFO alone determined 29% of the variation in FATmax (p < 0.01), noting that individuals with body fat > 35% showed a heart rate of 61-66% HRpeak while individuals with < 35% body fat showed a heart rate between 57 and 64% HRpeak. Neither biological sex nor the analytical procedure for computing the fat oxidation kinetics were associated with MFO and FATmax.

CONCLUSION

Relative heart rate rather than relative oxygen uptake should be used for establishing FATmax reference values in patients with obesity. A heart rate of 61-66% HRpeak should be recommended to patients with > 35% body fat while a heart rate of 57-64% HRpeak should be recommended to patients with body fat < 35%. Moreover, training volume must be higher in adults to achieve a similar fat oxidation compared with adolescents whereas exercising on a treadmill requires a lower training volume to achieve significant fat oxidation in comparison with stationary cycling.

Chronic high-intensity interval training and moderate-intensity continuous training are both effective in increasing maximum fat oxidation during exercise in overweight and obese adults: A meta-analysis

Objective

to (1) systematically review the chronic effect of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on maximal fat oxidation (MFO) in overweight and obese adults, and (2) explore MFO influencing factors and its dose-response relationships with HIIT and MICT.

Methods

Studies using a between-group design involving overweight and obese adults and assessing the effect of HIIT and MICT on MFO were included. A meta-analysis on MFO indices was conducted, and the observed heterogeneities were explored through subgroup, regression, and sensitivity analyses.

Results

Thirteen studies of moderate to high quality with a total of 519 overweight and obese subjects were included in this meta-analysis (HIIT, n = 136; MICT, n = 235; Control, n = 148). HIIT displayed a statistically significant favorable effect on MFO compared to no-training (MD = 0.07; 95%CI [0.03 to 0.11]; I2 = 0%). Likewise, MICT displayed a statistically significant favorable effect on MFO compared to no-training (MD = 0.10; 95%CI [0.06 to 0.15]; I2 = 95%). Subgroup and regression analyses revealed that exercise intensity (Fatmax vs. non-Fatmax; %VO2peak), exercise mode, BMI, and VO2peak all significantly moderated MICT on MFO. When analyzing studies that have directly compared HIIT and MCIT in obese people, it seems there is no difference in the MFO change (MD = 0.01; 95%CI [-0.02 to 0.04]; I2 = 64%). No publication bias was found in any of the above meta-analyses (Egger's test p > 0.05 for all).

Conclusion

Both HIIT and MICT are effective in improving MFO in overweight and obese adults, and they have similar effects. MCIT with an intensity of 65-70% VO2peak, performed 3 times per week for 60 min per session, will optimize MFO increases in overweight and obese adults. Given the lack of studies examining the effect of HIIT on MFO in overweight and obese adults and the great diversity in the training protocols in the existing studies, we were unable to make sound recommendations for training.

The role of sex in the relationship between fasting adipokines levels, maximal fat oxidation during exercise, and insulin resistance in young adults with excess adiposity

AIM

Previous evidence suggest that a sexual dimorphism in exercise fat oxidation and adipokines levels may explain a lower risk of cardio-metabolic disorders in women. Therefore, we investigated the role of sex in the relationship between adipokines levels, maximal fat oxidation (MFO) during exercise and insulin resistance.

METHODS

Fifty young adults with excess adiposity (31 women; body fat: 38.7 ± 5.3%) were included in this study. The fasting levels of leptin, adiponectin, glucose and insulin were determined from blood samples and the homeostatic model assessment of insulin resistance index (HOMA-IR) subsequently calculated. Body fat percentage and visceral adipose tissue (VAT) were assessed through dual-energy X-ray absorptiometry whereas MFO was estimated during an incremental-load exercise test after an overnight fasting through indirect calorimetry.

RESULTS

Men had lower levels of body fat (d = 1.80), adiponectin (d = 1.35), leptin (d = 0.43) and MFO (d = 1.25) than women. Conversely, men showed higher VAT (d = 0.85) and fasting glucose levels (d = 0.89). No sex differences were observed in HOMA-IR (d = 0.34). Adipokines levels were not associated with MFO in both sexes (r < 0.30), whereas adiponectin levels were inversely related with HOMA-IR in both men (r = -0.58) and women (r = -0.50). Leptin concentration was associated to HOMA-IR only in men (r = 0.41), while no statistically significant relationships were observed between MFO and HOMA-IR in both sexes (r < 0.44).

CONCLUSION

Insulin resistance was similar between sexes regardless of superior levels of adipokines and MFO during exercise in women. Therefore, adiponectin and leptin may regulate glucose homeostasis without altering whole body fat oxidation rate during exercise.

Accumulated Short Bouts of Walking in Older Adults With Type 2 Diabetes: Effects on Glycosylated Hemoglobin (HbA1c) and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR)

The current study examined the effects of accumulated short bouts of walking on glycosylated hemoglobin (HbA1c) and homeostasis model assessment of insulin resistance (HOMA-IR) of older adults with type 2 diabetes. Differences in variables between models of accumulated bouts of walking and 10,000 steps were also investigated. Sedentary participants (N = 38) were randomized into one of three groups: accumulated 10-minute bouts of walking at 100 steps/min (10/100MW), accumulated 10,000 steps (10KS), or control. HbA1c, HOMA-IR, blood lipids, and cardiorespiratory fitness (VO2max) were assessed before and after the intervention. VO2max, HbA1c, and HOMA-IR in the 10/100MW and 10KS groups showed significant and comparable improvements postintervention compared to preintervention (p < 0.05). Furthermore, the change in average daily step count was significantly associated with the change in HbA1c of the two walking groups (r = -0.61 for 10KS and r = -0.63 for 10/100MW; p < 0.05). Accumulated short bouts of walking at 100 steps/min and 10,000 steps daily improved HbA1c and HOMA-IR of older adults with type 2 diabetes. [Research in Gerontological Nursing, 16(5), 250-258.].

Crossover point and maximal fat oxidation training effects on blood lipid metabolism in young overweight women: a pilot study

Purpose: To determine the effects of weight reduction schemes using the exercise intensities corresponding to maximal fat oxidation (FATmax) and crossover point (COP). The effects of different intervention protocols on blood lipid metabolism were compared to explore how fat can be consumed and used more efficiently and provide a theoretical basis for weight loss through exercise. Methods: This study included 30 young overweight women randomly divided into the COP, FATmax, and control groups. Participants in the COP and FATmax groups exercised for 45 min four times a week for 8 weeks after the individual treadmill exercise test. The control group did not perform any exercise. Results: After 8 weeks of training, participants in the COP group significantly decreased weight (2.6 ± 3.3 kg), body mass index (0.91 ± 1.26 kg/m²), body fat percentage (1.21% ± 1.50%), and fat mass (1.90 ± 2.30 kg) (p < 0.05). They also had significantly decreased hip circumference (4.8 ± 3.3 cm), serum apolipoprotein B (ApoB) levels (15.48 ± 14.19 mg/dL), and ApoB/apolipoprotein AI (ApoAI) ratios (0.47 ± 0.37) (p < 0.01). However, their serum ApoAI levels were significantly increased (14.18 ± 10.24 mg/dL; p < 0.01). Participants in the FATmax group had significantly decreased hip circumference (2.4 ± 2.0 cm), serum ApoB levels (14.49 ± 11.00 mg/dL), and ApoB/ApoAI ratios (0.59 ± 0.30) (p < 0.01) but significantly increased serum ApoAI levels (29.53 ± 13.29 mg/dL; p < 0.01). No significant changes in physiological indexes were observed in participants in the control group. Conclusion: Personalised exercise intervention positively affected central obesity, effectively improving blood lipid metabolism and fat oxidation, reducing cardiovascular disease risk in young overweight women. COP training improved weight and body composition better than the FATmax exercise, while the latter provided greater improvements in serum ApoAI levels.

Long-term effects of different exercise training modes on cytokines and adipokines in individuals with overweight/obesity and cardiometabolic diseases: A systematic review, meta-analysis, and meta-regression of randomized controlled trials

The present study aimed to investigate the evidence on the effects of different long-term training interventions (aerobic [AeT], resistance [RT], and combined [COMB]) and spontaneous physical activity (PA) in modifying cytokines and adipokines in individuals with overweight or obesity with or without cardiometabolic diseases while considering potential confounders. Although exercise interventions have become a potentially effective tool for preventing and treating metabolic diseases, the evidence provided by previous systematic reviews is inconclusive since several potential confounders have yet to be addressed. Therefore, we conducted a systematic literature search in Medline, Cochrane, and Embase databases from January 2000 to July 2022 and performed a meta-analysis. Inclusion criteria retrieved 106 full texts comprising 8,642 individuals with a range BMI of 25.1-43.8 kg m^-2 . We found that independently of the training mode, exercise had a beneficial effect on diminishing Adiponectin, C-reactive protein (CRP), IL-6, IL-18, IL-20, Leptin, sICAM, and TNF-α levels circulating levels. Furthermore, by subsequent analysis, we detected differential effects of AeT, RT, and COMB, with sex, age, body composition, and trial length acting as moderators. The comparison of training modes revealed a difference favoring COMB over AeT for regulating the increase in CRP with no differences in the remaining biomarkers. Meta-regression analysis revealed an effect of change in maximal oxygen uptake (VO_2max ) on CRP, IL-6, and TNF-α, while IL-10 was influenced by the change in body fat. The results suggest that all interventions, except PA, are effective in lessening this population's inflammatory status, provided that exercise results in an increase of VO_2max .

Impacto de los diferentes tipos de entrenamiento físico sobre la composición corporal en mujeres adultas con obesidad: una revisión bibliográfica

Introducción: La obesidad sigue siendo uno de los problemas más grandes de salud pública en todo el mundo. Se conoce que está asociada con una gran variedad de enfermedades; en mujeres obesas, aún se desconoce la forma idónea para realizar una adecuada prescripción física. Objetivo: revisar los tipos de entrenamientos físicos de ensayos controlados aleatorizados publicados en la base de datos PubMed entre los años 2015 a 2022 sobre los cambios en la composición corporal en mujeres adultas de 18 a 65 años con obesidad. Metodología: se utilizó a modo de filtro la “Herramienta de Evaluación de Calidad Validada para Estudios Cuantitativos”. Resultados: la búsqueda arrojó 586 artículos, de los cuales el 93.85% fueron eliminados; 6.14% pasaron por un filtro que dejó un total de 1.7%. Conclusión: en mujeres adultas con obesidad, se ha demostrado que todos los tipos de entrenamiento físico sirven para generar cambios en la composición corporal. Introduction: Obesity continues to be one of the biggest public health problems worldwide. It is known to be associated with a wide variety of diseases; in obese women, the ideal way to carry out an adequate physical prescription is still unknown. Objective: to review the types of physical training in randomized controlled trials published in the PubMed database between 2015 and 2022 on changes in body composition in adult women aged 18 to 65 with obesity. Methodology: the "Validated Quality Assessment Tool for Quantitative Studies" was used as a filter. Outcomes: the search yielded 586 articles, of which 93.85% were eliminated; 6.14% went through a filter that left a total of 1.7%. Conclusion: in adult women with obesity, it has been shown that all types of physical training serve to generate changes in body composition.

Beyond the Calorie Paradigm: Taking into Account in Practice the Balance of Fat and Carbohydrate Oxidation during Exercise?

Recent literature shows that exercise is not simply a way to generate a calorie deficit as an add-on to restrictive diets but exerts powerful additional biological effects via its impact on mitochondrial function, the release of chemical messengers induced by muscular activity, and its ability to reverse epigenetic alterations. This review aims to summarize the current literature dealing with the hypothesis that some of these effects of exercise unexplained by an energy deficit are related to the balance of substrates used as fuel by the exercising muscle. This balance of substrates can be measured with reliable techniques, which provide information about metabolic disturbances associated with sedentarity and obesity, as well as adaptations of fuel metabolism in trained individuals. The exercise intensity that elicits maximal oxidation of lipids, termed LIPOXmax, FATOXmax, or FATmax, provides a marker of the mitochondrial ability to oxidize fatty acids and predicts how much fat will be oxidized over 45–60 min of low- to moderate-intensity training performed at the corresponding intensity. LIPOXmax is a reproducible parameter that can be modified by many physiological and lifestyle influences (exercise, diet, gender, age, hormones such as catecholamines, and the growth hormone-Insulin-like growth factor I axis). Individuals told to select an exercise intensity to maintain for 45 min or more spontaneously select a level close to this intensity. There is increasing evidence that training targeted at this level is efficient for reducing fat mass, sparing muscle mass, increasing the ability to oxidize lipids during exercise, lowering blood pressure and low-grade inflammation, improving insulin secretion and insulin sensitivity, reducing blood glucose and HbA_1c in type 2 diabetes, and decreasing the circulating cholesterol level. Training protocols based on this concept are easy to implement and accept in very sedentary patients and have shown an unexpected efficacy over the long term. They also represent a useful add-on to bariatric surgery in order to maintain and improve its weight-lowering effect. Additional studies are required to confirm and more precisely analyze the determinants of LIPOXmax and the long-term effects of training at this level on body composition, metabolism, and health.

Changes in Fat Oxidation and Body Composition after Combined Exercise Intervention in Sedentary Obese Chinese Adults

(1) Background: Evidence suggests that aerobic exercise and high-intensity interval training (HIIT) might increase fat oxidation and reduce fat. However, limited research has examined the effects of combining progressive aerobic exercise and HIIT interventions in sedentary adults with overweight and obesity, and differences in its effects between men and women remain unclear. The purpose of this study was to investigate the effects of combined progressive aerobic exercise and HIIT (CAEH) on fat oxidation and fat reduction in sedentary Chinese adults and compare sex differences in sedentary adults after seven weeks. (2) Methods: Eighty-four sedentary obese adults were enrolled and allocated to two groups in baseline (experimental (EXP) group:42; control (CON) group:42), and fifty-six subjects (EXP:31; CON:25) completed the experiments and were included in the final analysis. Subjects in the EXP group performed CAEH three times per week for seven weeks. Subjects in the CON group were advised to continue with their normal daily activities. Anthropometric, lipid profile, cardiorespiratory fitness, and fat oxidation outcomes were assessed before and after the intervention. (3) Results: After seven weeks of the CAEH intervention, compared with the CON group, the EXP group showed significant increases in fat oxidation at rest (FO_rest) (+0.03 g/min, p < 0.01), maximal fat oxidation (MFO) (+0.05 g/min, p < 0.01), and maximal oxygen intake (VO₂max) (+3.2 mL/kg/min, p < 0.01). The changes in the percentages of the FO_rest (+57%) and the VO₂max (+16%) were significantly greater (+20%, +6%) in males than in females (p < 0.05, p < 0.05). The body mass index (BMI) (−1.2 kg/m², p < 0.01), body fat percentage (−3.2%, p < 0.001), visceral fat area (−12.8 cm², p < 0.001), and total cholesterol (TC) levels (−0.4 mmol/L, p < 0.05) were significantly decreased in the EXP group. (4) Conclusions: Seven weeks of the CAEH intervention effectively improved FO_rest, MFO, and VO₂max in sedentary obese adults, and the improvements in FO_rest and VO₂max were more pronounced in males than in females. CAEH also improved body composition and TC levels in sedentary obese adults.

Impact of training modes on fitness and body composition in women with obesity: A systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the effectiveness of different exercise modalities and determine the optimal exercise prescription for improving cardiorespiratory fitness, body composition, and metabolic health of women with obesity.

METHODS

A systematic review of randomized controlled trials (RCTs) published between January 1988 and October 2020 was conducted. The RCTs were screened using the following inclusion criteria: 1) participants: women aged 18 to 65 years with BMI > 30 kg/m² and without comorbidities; 2) intervention: exercise; 3) comparison: non-intervention control; and 4) outcomes measures: cardiorespiratory fitness (maximal oxygen consumption), body composition (i.e., body weight, percentage body fat), and/or metabolic measures (i.e., blood pressure, cholesterol).

RESULTS

A total of 20 RCTs with a total of 2,062 participants were included. Although the results showed that any form of exercise was more effective than control, improvements in fitness and body composition were modest. Aerobic exercise (vigorous and moderate intensity) appeared most promising for improving fitness and body weight, whereas low-load resistance training resulted in the largest improvements in body fatness.

CONCLUSIONS

In women living with obesity, aerobic exercise was consistently effective in improving fitness and body composition. Although both resistance training and combined exercise interventions appear promising, more research is needed to evaluate their efficacy and determine an optimal exercise prescription for this population.

A Combination of Aerobic Exercise at Fatmax and Low Resistance Training Increases Fat Oxidation and Maintains Muscle Mass, in Women Waiting for Bariatric Surgery

PURPOSE

There is no consensus on the best exercise recommendation for women affected by severe obesity while they are waiting for bariatric surgery. For this reason, the effects of a combination of aerobic exercise performed at the intensity at which maximal fat oxidation is reached (Fatmax) with low-intensity resistance training were studied.

MATERIALS AND METHODS

Twenty sedentary middle-aged Caucasian women (43.2 ± 7.5 years, BMI = 46.5 ± 5.9 kg·m^-2) were allocated to a control group (CG, n = 10) that followed solely the conventional preoperative care or to an experimental group (EG, n = 10) that, in addition, performed a 12-week individualized and supervised physical activity program (PAP) that combined aerobic training at Fatmax with low-intensity resistance training.

RESULTS

After the PAP, maximal fat oxidation during exercise increased in the EG (0.187 ± 0.068 vs 0.239 ± 0.080 g·min^-1, p = 0.025, pre vs. post, respectively), but resting fat oxidation did not (0.088 ± 0.034 vs 0.092 ± 0.029 g·min^-1, p = 0.685, pre vs. post, respectively). Additionally, the resting metabolic rate in the EG was also unchanged (1869 ± 406 vs. 1894 ± 336 kcal; p = 0.827, pre vs. post, respectively), probably because of the effects of resistance training on the maintenance of fat-free mass. No significant changes were observed in the CG.

CONCLUSION

A PAP that combines aerobic exercise at Fatmax with low resistance training may counteract some of the deleterious side effects of the standard presurgical care of women waiting for bariatric surgery and increase maximal fat oxidation during exercise.

An updated systematic review on the effects of aerobic exercise on human blood lipid profile

Sedentary lifestyle and dyslipidemia are well-recognized risk factors for cardiovascular diseases (CVD). Changes in blood lipid profile (total cholesterol (TC), triglycerides, high-density lipoprotein [HDL], and low-density lipoprotein [LDL]) due to the exercise may be beneficial for decreasing CVD-related events. In this review we aimed to investigate the effect of different types of exercise on lipid profile components in people with different health conditions and age ranges. A systematic search was performed covering PubMed, Web of Science, and Google Scholar for English articles from 2010 until November 2021. Finally, 31 studies were included in our study. Results showed that exercise in younger individuals sometimes resulted in no significant changes of any of the variables or some of them; however, efficient improvement was observed in all studies of older and middle-age groups. In terms of health condition and gender; healthy individuals, overweight people, subjects with type 2 diabetes and obesity, and male participants found to have benefited more from the exercise. In patients with chronic kidney diseases lipid profile improvement was not significant. The cardiac rehabilitation program, particularly comprehensive cardiac rehabilitation, proved to be more beneficial than exercise alone in the case of cardiovascular patients and those at elevated risk of CVD. In conclusion exercise is beneficial in terms of improving lipid profile but for younger population, and those with kidney problems and CVD patients, more further preparations are needed under the supervision of experts in the field of sports and medicine to achieve the desired result. Also, more studies are needed for these groups in order to provide a definite and reliable conclusion.

EFFECTS OF EXERCISE TYPE AND INTENSITY ON VISFATIN AND THE METABOLIC SYNDROME IN OBESITY

ABSTRACT Objective: Visfatin may regulate a variety of physiological functions and it has great potential to significantly enhance our knowledge of the treatment of metabolic syndrome. Metabolic syndrome (MS) refers to metabolic abnormalities, such as abdominal obesity, dyslipidemia, high low-density cholesterol, high blood pressure and diabetes, and physical activity is an important factor for the management of MS. Therefore, the purpose of this study is to investigate the effects of visfatin on MS and MS risk factors through differences in aerobic exercise intensity and exercise type based on the premise of the same amount of exercise (energy expenditure of 400 kcal per day). Method: Thirty two obese, middle-aged women were randomly assigned to exercise intensity groups VO2max 50% (MAE, n=8) and VO2max 80% (VAE, n=8) and to type of exercise groups VO2max 50% + TRX (MARE, n=8) and VO2max 80% + TRX (VARE, n=8). The exercise program was performed 5 times a week. The data was analyzed using two-way repeated measures ANOVA and post-hoc tests within groups with LSD. Results: Body weight (p<.01 and p<.001) and % body fat (p<.05 and p<.01) significantly decreased in all groups and visfatin only increased significantly after exercise in the VARE group (p<.05). TG, glucose, and waist circumstance (p<.05, p<.01, and p<.001) significantly decreased in all groups and HDL-C (p<.05) only increased significantly after exercise only in the MARE group. Conclusion: These results suggest that, in spite of differences in exercise intensity and exercise type, exercise is effective in improving obesity and MS risk factors, but further research is needed on the exact mechanisms of visfatin. Level of evidence I; Therapeutic Studies Investigating the Results of Treatment .

Chronic Effect of Fatmax Training on Body Weight, Fat Mass, and Cardiorespiratory Fitness in Obese Subjects: A Meta-Analysis of Randomized Clinical Trials

Exercise training performed at the maximal fat oxidation intensity (FMT) stands out as a potential treatment of overweight and obesity. This work is a meta-analysis of randomized clinical trials of studies about the effect of FMT on fat mass and maximal oxygen consumption using PubMed, SCOPUS, EBSCOhost, and ScienceDirect as databases. Two independent reviewers selected 11 trials from 356 publications identified by the following keywords: fatmax, lipoxmax, maximal fat oxidation, peak of fat oxidation, physical training, physical exercise, body fat (BF), fat mass, overweight, and obesity. The risk of bias was assessed following the Cochrane Guidelines. The pooled mean difference was computed for each outcome with the random-effects model and the inverse-variance method. The meta-analysis was performed with the RevMan software v 5.3, and the heterogeneity across studies by the I². The statistical significance was accepted at p < 0.05. Results showed that the FMT reduced body weight (MD = -4.30 kg, p < 0.01, I² = 0%), fat mass (MD = -4.03 kg, p < 0.01, I² = 0%), and waist circumference (MD = -3.34 cm, p < 0.01). Fat-free mass remains unchanged (MD = 0.08 kg, p = 0.85), but maximal oxygen consumption increased (MD = 2.96 mL∙kg^-1∙min^-1, p < 0.01, I² = 0%). We conclude that FMT at short and medium-term (eight to twenty weeks) reduces body weight and BF, increasing cardiovascular fitness in low physical fitness people with obesity.

Taurine supplementation associated with exercise increases mitochondrial activity and fatty acid oxidation gene expression in the subcutaneous white adipose tissue of obese women

PURPOSE

To evaluate the effects of taurine supplementation associated or not with chronic exercise on body composition, mitochondrial function, and expression of genes related to mitochondrial activity and lipid oxidation in the subcutaneous white adipose tissue (scWAT) of obese women.

METHODS

A randomized and double-blind trial was developed with 24 obese women (BMI 33.1 ± 2.9 kg/m², 32.9 ± 6.3 y) randomized into three groups: Taurine supplementation group (Tau, n = 8); Exercise group (Ex, n = 8); Taurine supplementation + exercise group (TauEx, n = 8). The intervention was composed of 3 g of taurine or placebo supplementation and exercise training for eight weeks. Anthropometry, body fat composition, indirect calorimetry, scWAT biopsy for mitochondrial respiration, and gene expression related to mitochondrial activity and lipid oxidation were assessed before and after the intervention.

RESULTS

No changes were observed for the anthropometric characteristics. The Ex group presented an increased resting energy expenditure rate, and the TauEx and Ex groups presented increased lipid oxidation and a decreased respiratory quotient. Both trained groups (TauEx and Ex) demonstrated improved scWAT mitochondrial respiratory capacity. Regarding mitochondrial markers, no changes were observed for the Tau group. The TauEx group had higher expression of CIDEA, PGC1a, PRDM16, UCP1, and UCP2. The genes related to fat oxidation (ACO2 and ACOX1) were increased in the Tau and Ex groups, while only the TauEx group presented increased expression of CPT1, PPARa, PPARγ, LPL, ACO1, ACO2, HSL, ACOX1, and CD36 genes.

CONCLUSION

Taurine supplementation associated with exercise improved lipid metabolism through the modulation of genes related to mitochondrial activity and fatty acid oxidation, suggesting a browning effect in the scWAT of obese women.

Continuous walking and time- and intensity-matched interval walking: Cardiometabolic demand and post-exercise enjoyment in insufficiently active, healthy adults

We compared cardiometabolic demand and post-exercise enjoyment between continuous walking (CW) and time- and intensity-matched interval walking (IW) in insufficiently active adults. Sixteen individuals (13 females and three males, age 25.3 ± 11.1 years) completed one CW and one IW session lasting 30 min in a randomised-counterbalanced design. For CW, participants walked at a mean intensity of 65-70% predicted maximum heart rate (HR_max). For IW, participants alternated between 3 min at 80% HR_max and 2 min at 50% HR_max. Expired gas was measured throughout each protocol. Participants rated post-exercise enjoyment following each protocol. Mean HR and V˙O₂ showed small positive differences in IW vs. CW (2, 95%CL 0, 4 beat.min^-1; d = 0.23, 95%CL 0.06, 0.41 and 1.4, 95%CL 1.2 ml.kg^-1.min^-1, d = 0.36, 95%CL 0.05, 0.65, respectively). There was a medium positive difference in overall kcal expenditure in IW vs. CW (25, 95%CL 7 kcal, d = 0.58, 95%CL 0.33, 0.82). Post-exercise enjoyment was moderately greater following IW vs. CW (9.1, 95%CL 1.4, 16.8 AU, d = 0.62, 95%CL 0.06, 0.90), with 75% of participants reporting IW as more enjoyable. Interval walking elicits meaningfully greater energy expenditure and is more enjoyable than CW in insufficiently active, healthy adults.

Effects of Aerobic Training With No Caloric Restriction on Serum Resistin and Lipid Profile in Inactive Overweight Women

Introduction: Obesity is a major risk factor for inflammation and cardiovascular diseases. We tried to assess whether 12 weeks of aerobic exercises affect serum resistin level and lipid profile in overweight females or not. Methods: For this purpose, 32 non-trained adult females with the mean age of 38 ± 7 years old and body mass index (BMI) of 32 ± 3 kg/m2 were randomly assigned to aerobic exercise (n=16) and control (n=16) groups. Twelve weeks of aerobic exercise program including 3 sessions weekly at 60-75% of maximum heart rate was considered. Fasting serum resistin level, lipid profile (total cholesterol [TC], low-density lipoprotein [LDL] and high-density lipoprotein [HDL] cholesterol, and triglyceride [TG]), and anthropometric indexes were measured and compared between the two groups before and after training. Results: Serum resistin, lipid profile markers, and anthropometrical indexes were not significantly different at baseline between the two groups (P>0.05). TG, TC, LDL, and serum resistin did not change significantly after the intervention in the exercise group (P>0.05). However, a significant increase in HDL (exercise: 46.3 ± 9.6 vs. 51.4 ± 8.5, P=0.011; control: 45.8 ± 7.9 vs. 46.8 ± 6.9 P=0.326) and a significant decrease in LDL/HDL ratio (exercise: 2.94 ± 0.12 vs. 2.47 ± 0.19, P=0.019; control: 3.14 ± 0.23 vs. 3.18 ± 0.63, P=0.265) were observed after the intervention. Other variables in the control group remained unchanged. Conclusion: Aerobic exercises had no impacts on the inflammatory profile but could improve lipid profile with an emphasis on HDL in adult obese women.

Physiological response and cardiorespiratory adaptation after a 6-week Nordic Walking training targeted at lipid oxidation in a group of post-menopausal women

This study examined the effects of a 6-week Nordic Walking (NW) training, at the intensity corresponding to the dominance of lipid metabolism, on the levels of selected physiological indices, the haemodynamic indices of the cardiovascular system and physical fitness in sedentary women older than 55 years of age. In addition, the physiological response of the female body to the walking effort on treadmill with poles (NW) and without poles (W) was compared and the influence of training on this response was determined. A single group study with a pre-test/post-test study design was conducted. Eighteen women performed NW controlled intensity training 3 times a week for 6 weeks. Body composition, resting blood pressure (BP), heart rate (HR), maximum oxygen uptake (VO₂max) as well as circulatory and respiratory indices in two graded walking efforts on mechanical treadmill NW and W were measured before and after training period. The intensity of workouts, which considered the dominance of lipid metabolism, was determined individually, based on the dynamics of changes in the level of physiological indices during the graded intensity NW. After the course of training, body mass, fat mass, resting BP and HR decreased significantly (p < 0.05). HR and respiratory exchange ratio recorded during NW and W at 1.75 m^.s^-1 walking speed decreased, while the oxygen pulse increased (p < 0.05). VO₂max increased significantly (p < 0.05). Before and after the training period HR, oxygen uptake per minute, and energy expenditure during NW were significantly higher than in W (p < 0.05). The study showed that 6-week NW training at the intensity corresponding to the dominance of lipid metabolism can provide improvement in body composition, cardiovascular function and physical performance in previously sedentary women. NW compared to the regular walk with the same speed revealed higher energy expenditure.

Exercise intensity and physical fitness modulate lipoproteins profile during acute aerobic exercise session

Physical inactivity has emerged as an important cardiometabolic risk factor; however, the beneficial impacts of physical exercise according physical fitness status are still unclear. To analyze the lipoproteins and immune-endocrine response to acute aerobic exercise sessions performed at different intensities according physical fitness status and evaluated the gene expression in monocyte cells. Twelve individuals, divided into Low and High VO_2max, performed three randomized acute exercise sessions at low (<60% VO_2max), moderate (60-75% VO_2max), and high (>90% VO_2max) intensities. Blood samples were collected pre, immediately post, and 60 minutes post-exercise to analyze NEFA, triacylglycerol, non-HDL-c, HDL-c, PAI-1, leptin and adiponectin concentrations. Blood samples were collected from another set of twelve individuals for use in monocyte cell cultures to analyze L-CAT, CETP, and AMPK gene expressions. Low VO_2max group pre-exercise exhibited higher postprandial leptin and total cholesterol concentrations than High VO_2max group (p < 0.05). Exercise performed in high-intensity promoted a decreased leptin and NEFA levels (p < 0.05, for both), but for PAI-1 levels was decreased (p < 0.05) only for the Low VO_2max group. Triacylglycerol levels decreased after all exercise sessions (p < 0.05) for both groups, and HDL-c exhibited decrease during moderate-intensity (p < 0.05), but this scenario was attenuated in Low VO_2max group. Low VO_2max individuals exhibit some metabolic-endocrine disruption, and acute aerobic exercise sessions performed at low, moderate, and high intensities are capable of modulating metabolic-endocrine parameters, mainly at high-intensity, in a physical fitness-dependent way, given that Low VO_2max group was more responsive and seem to be able to appropriate more exercise-related benefits.

The beneficial effects of a water-based aerobic exercise session on the blood lipids of women with dyslipidemia are independent of their training status

OBJECTIVES

To evaluate the acute effects of a session of water-based aerobic exercise on the blood lipid levels of women with dyslipidemia and to compare these results according to their training status.

METHOD

Fourteen premenopausal women with dyslipidemia, aged 40-50 years, participated in two water-based aerobic exercise sessions, the first when they were generally sedentary and the second after they were trained with a water-based aerobic training program for 12 weeks. Both experimental sessions were performed using the same protocol, lasted 45 min, and incorporated an interval method, alternating 3 min at a rating of perceived exertion (RPE) of 13 and 2 min at an RPE of 9. Total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and lipoprotein lipase enzyme (LPL) were obtained through venous blood collection before and immediately after each session. A generalized estimating equation method and Bonferroni tests were conducted (with time and training status as factors) for statistical analyses.

RESULTS

At enrollment, the mean age of the participants was 46.57 years (95% confidence interval [CI] 44.81-48.34). The statistical analyses showed a significant time effect for all variables (TC: p=0.008; TG: p=0.012; HDL: p<0.001; LPL: p<0.001) except for LDL (p=0.307). However, the training status effect was not significant for any variable (TC: p=0.527; TG: p=0.899; HDL: p=0.938; LDL: p=0.522; LPL: p=0.737). These results indicate that the TC and TG levels reduced and the HDL and LPL concentrations increased from pre- to post-session in similar magnitudes in both sedentary and trained women.

CONCLUSIONS

A single water-based aerobic exercise session is sufficient and effective to beneficially modify the lipid profile of women with dyslipidemia, regardless of their training status.

Effects of a short workplace exercise program on body composition in women: A randomized controlled trial

Physical inactivity and poor diet cause alterations in body composition, which in turn increases risk factors for cardiovascular and metabolic diseases. Sixty-three women from different work environments were randomly assigned to an intervention (n = 34) or control (n = 29) group. The intervention was a short-term aerobic exercise program (12 weeks) at their workplace. Participants assigned to the control group did not perform any form of physical exercise. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Diet was assessed using the Mediterranean Diet Quality Questionnaire (KIDMED) and nutrient balance by the Food Frequency Questionnaire. Researchers suggest that a short-term aerobic exercise program produces beneficial effects on body composition.

Diurnal Variation of Maximal Fat-Oxidation Rate in Trained Male Athletes

Purpose: To analyze the diurnal variation of maximal fat oxidation (MFO) and the intensity that elicits MFO (Fatmax) in trained male athletes. Methods: A total of 12 endurance-trained male athletes age 24.7 (4.1) y participated in the study. The authors measured MFO, Fatmax, maximum oxygen uptake (VO2max), and VO2 percentage at ventilatory threshold 2 with a graded exercise protocol performed on 2 days separated by 1 wk. One test was performed in the morning and the other in the afternoon. The authors assessed the participants’ chronotype using the HÖME questionnaire. Results: MFO and Fatmax were greater in the afternoon than in the morning (Δ = 13%, P < .001 and Δ = 6%, P = .001, respectively), whereas there were similar VO2max and ventilatory threshold 2 in the morning, than in the afternoon test (Δ = 0.2%, P = .158 and Δ = 7%, P = .650, respectively). There was a strong positive association between VO2max and MFO in both morning and afternoon assessments (R2 = .783, P = .001 and R2 = .663, P < .001, respectively). Similarly, there was a positive association between VO2max and Fatmax in both morning and afternoon assessments (R2 = .406, P = .024 and R2 = .414, P = .026, respectively). Conclusion: MFO and Fatmax may partially explain some of the observed diurnal variation in the performance of endurance sports.

Aerobic exercise training at maximal fat oxidation intensity improves body composition, glycemic control, and physical capacity in older people with type 2 diabetes

Background

Aerobic training has been used as one of the common treatments for type 2 diabetes; however, further research on the individualized exercise program with the optimal intensity is still necessary. The purpose of this study was to investigate the effects of supervised exercise training at the maximal fat oxidation (FATmax) intensity on body composition, glycemic control, lipid profile, and physical capacity in older people with type 2 diabetes.

Methods

Twenty-four women and 25 men with type 2 diabetes, aged 60–69 years. The exercise groups trained at the individualized FATmax intensity for 1 h/day for 3 days/week over 16 weeks. No dietary intervention was introduced during the experimental period. Whole body fat, abdominal fat, oral glucose tolerance test, lipid profile, and physical capacity were measured before and after the interventions.

Results

FATmax intensity was at 41.3 ± 3.2% VO₂max for women and 46.1 ± 10.3% VO₂max for men. Exercise groups obtained significant improvements in body composition, with a special decrease in abdominal obesity; decreased resting blood glucose concentration and HbA1c; and increased VO₂max, walking ability, and lower body strength, compared to the non-exercising controls. Daily energy intake and medication remained unchanged for all participants during the experimental period.

Conclusion

Beside the improvements in the laboratory variables, the individualized FATmax training can also benefit daily physical capacity of older people with type 2 diabetes.

Physical training, UCP1 expression, mitochondrial density, and coupling in adipose tissue from women with obesity

BACKGROUND

Exercise training may improve energy expenditure, thermogenesis, and oxidative capacities. Therefore, we hypothesized that physical training enhances white adipose tissue mitochondrial oxidative capacity from obese women.

OBJECTIVE

To evaluate mitochondrial respiratory capacity, mitochondrial content, and UCP1 gene expression in white adipose tissue from women with obesity before and after the physical training program.

METHODS

Women (n = 14, BMI 33 ± 3 kg/m² , 35 ± 6 years, mean ± SD) were submitted to strength and aerobic exercises (75%-90% maximum heart rate and multiple repetitions), 3 times/week during 8 weeks. All evaluated subjects were paired, before and after training for resting metabolic rate (RMR), substrate oxidation (lipid and carbohydrate) by indirect calorimeter, deuterium oxide body composition, and aerobic maximum velocity (V_max ) test. At the beginning and at the ending of the protocol, abdominal subcutaneous adipose tissue was collected to measure the mitochondrial respiration by high-resolution respirometry, mitochondrial content by citrate synthase (CS) activity, and UCP1 gene expression by RT-qPCR.

RESULTS

Combined physical training increased RMR, lipid oxidation, and V_max but did not change body weight/composition. In WAT, exercise increased CS activity, decreased mitochondrial uncoupled respiration and mRNA of UCP1. RMR was positively correlated with fat-free mass.

CONCLUSION

Physical training promotes an increase in mitochondrial content without changing tissue respiratory capacity, a reduction in mitochondrial uncoupling degree and UCP1 mRNA expression in WAT. Finally, it improved the resting metabolic rate, lipid oxidation and physical performance, independent of the body changing free, or fat mass in obese women.

Health Benefits of Endurance Training: Implications of the Brain-Derived Neurotrophic Factor-A Systematic Review

This article presents a concept that wide expression of brain-derived neurotrophic factor (BDNF) and its receptors (TrkB) in the nervous tissue, evoked by regular endurance training (ET), can cause numerous motor and metabolic adaptations, which are beneficial for human health. The relationships between the training-evoked increase of endogenous BDNF and molecular and/or physiological adaptations in the nervous structures controlling both motor performance and homeostasis of the whole organism have been presented. Due to a very wide range of plastic changes that ET has exerted on various systems of the body, the improvement of motor skills and counteraction of the development of civilization diseases resulting from the posttraining increase of BDNF/TrkB levels have been discussed, as important for people, who undertake ET. Thus, this report presents the influence of endurance exercises on the (1) transformation of motoneuron properties, which are a final element of the motor pathways, (2) reduction of motor deficits evoked by Parkinson disease, and (3) prevention of the metabolic syndrome (MetS). This review suggests that the increase of posttraining levels of BDNF and its TrkB receptors causes simultaneous changes in the activity of the spinal cord, the substantia nigra, and the hypothalamic nuclei neurons, which are responsible for the alteration of the functional properties of motoneurons innervating the skeletal muscles, for the enhancement of dopamine release in the brain, and for the modulation of hormone levels involved in regulating the metabolic processes, responsively. Finally, training-evoked increase of the BDNF/TrkB leads to a change in a manner of regulation of skeletal muscles, causes a reduction of motor deficits observed in the Parkinson disease, and lowers weight, glucose level, and blood pressure, which accompany the MetS. Therefore, BDNF seems to be the molecular factor of pleiotropic activity, important in the modulation processes, underlying adaptations, which result from ET.

Hypolipidemic Effect of Arthrospira (Spirulina) maxima Supplementation and a Systematic Physical Exercise Program in Overweight and Obese Men: A Double-Blind, Randomized, and Crossover Controlled Trial

Low-fat diets, lipid-modifying nutraceuticals and a higher level of physical activity are often recommended to reduce dyslipidemia. A double-blind, randomized, crossover, controlled trial was designed to evaluate the independent and synergistic effects of Arthrospira (Spirulina) maxima supplementation (4.5 g·day^-1) with or without performing a physical exercise program (PEP: aerobic exercise (3 days·week^-1) + high-intensity interval training (2 days·week^-1)) on blood lipids and BMI of 52 sedentary men with excess body weight. During six weeks, all participants were assigned to four intervention treatments (Spirulina maxima with PEP (SE), placebo with PEP (Ex), Spirulina maxima without PEP (Sm), placebo without PEP (C; control)) and plasma lipids were evaluated spectrophotometrically pre- vs. post intervention in stratified subgroups (overweight, obese and dyslipidemic subjects). Pre/post comparisons showed significant reductions in all plasma lipids in the SE group, particularly in those with dyslipidemia (p ≤ 0.043). Comparing the final vs. the initial values, BMI, total cholesterol, triglycerides and low-density lipoprotein cholesterol were decreased. High-density lipoprotein cholesterol increased in all treatment groups compared to C. Changes were observed mostly in SE interventions, particularly in dyslipidemic subjects (p < 0.05). Spirulina maxima supplementation enhances the hypolipidemic effect of a systematic PEP in men with excess body weight and dyslipidemia.

Relationship between individual ventilatory threshold and maximal fat oxidation (MFO) over different obesity classes in women

Objective

The use of the Individual Ventilatory Threshold (IVT), as parameter to prescribe exercise intensity in individuals with obesity, has become more frequent during the last years. This study aimed to evaluate the relationship between IVT and Maximal Fat Oxidation (MFO) in women with obesity.

Methods

Fifty-two obese female adults (age = 43.6±10.9 years; BMI = 38.5±5.2 kg/m²) were included in this study. According to the BMI classification, subjects were divided into three groups: Obese Class I (OBI, n = 16); Obese Class II (OBII, n = 20) and Obese Class III (OBIII, n = 16). All subjects performed an incremental graded exercise test to evaluate peak oxygen uptake (VO_2peak), IVT and MFO. MFO was evaluated using a stoichiometric equation. Fat max zone was determined for each subject within 10% of fat oxidation rates at MFO. For each HR, %HR_max, VO₂ and %VO_2peak variable, Pearson’s correlation test was done between IVT and MFO exercise intensity. When statistical correlation was found we used a comparative statistical analysis to assess differences between IVT and MFO. Statistical significance was set at P ≤ 0.05.

Results

For each HR, %HR_max, VO₂ and %VO_2peak variable there was a positive significant correlation (P<0.01) between IVT and MFO. No significant differences were found for HR, %HR_max, and VO₂ between IVT and MFO. %VO_2peak was significantly higher at IVT than at MFO (P = 0.03).

MFO rates were significantly higher in OBIII women than in women of the other two classes. In all subjects, IVT was within the fat max zone.

Conclusion

The use of HR and VO₂ corresponding to IVT could be a useful parameter not only to improve cardiorespiratory fitness but also to prescribe physical activity that maximize fat oxidation in obese subjects.

Fat Oxidation Rate as a Function of Plasma Lipid and Hormone Response in Endurance Athletes

Soria, M, Ansón, M, Lou-Bonafonte, JM, Andrés-Otero, MJ, Puente, JJ, and Escanero, J. Fat oxidation rate as a function of plasma lipid and hormone response in endurance athletes. J Strength Cond Res 34(1): 104-113, 2020-Plasma lipid changes during incremental exercise are not well known. The aim of this study was to investigate the relationship among fat oxidation rate, plasma lipids, and hormone concentrations in well-trained athletes. Twenty-six trained triathletes completed a graded cycle ergometer test to exhaustion increasing by 0.5 W·kg every 10 minutes. Fat oxidation rates were determined using indirect calorimetry. For each individual, maximal fat oxidation (MFO), the intensity at which MFO occurred (Fatmax), and the intensity at which fat oxidation became negligible (Fatmin) were determined. Blood samples for lipids and hormones analysis were collected at the end of each stage of the graded exercise test. All variables studied except insulin showed an increase at the end of incremental protocol with respect to basal levels. Free fatty acid reached significant increase at 60%VO2max and maximal levels at 70%VO2max. Low-density lipoprotein (LDL) and triglycerides (TG) decreased and showed lowest levels at 60%VO2max and reaching significant increases after 80%VO2max. High-density lipoprotein reached significant increase at 60%VO2max. Adrenaline and noradrenaline increased until the end of the incremental exercise, and significant differences were from 50%VO2max. These results suggest that exercise intensities are related to plasma lipids levels. In the zone when lipids oxidation is maximal, plasma LDL and TG variation differs from other lipids. These results may have application for the more adequate exercise intensity prescription to maximize the beneficial effects of exercise.

The Effect of Chronic Exercise Training on Leptin: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Leptin is a hormone associated with satiety, lipid oxidation, energy expenditure, and energy homeostasis. To date, the current body of research examining the effect of chronic exercise training on leptin has yielded inconsistent results.

OBJECTIVE

The purpose of this meta-analysis was to provide a quantitative estimate of the magnitude of change in leptin levels following participation in exercise interventions lasting ≥ 2 weeks.

METHODS

All studies included were peer-reviewed and published in English. To be included, studies randomized human participants to an exercise training group or non-exercise comparison group for an exercise training intervention. Leptin levels were measured at baseline, during, and/or after completion of the exercise training program. Random-effects models were used to aggregate a mean effect size (ES) and 95% confidence intervals (CIs), and identify potential moderators.

RESULTS

Seventy-two randomized controlled trials met the inclusion criteria and resulted in 107 effects (n = 3826). The mean ES of 0.24 (95% CI 0.16-0.32, p < 0.0001) indicated a decrease in leptin following an exercise training program. A decrease in %Fat (β = - 0.07, p < 0.01) was associated with a decrease in leptin after accounting for the type of control group (β = - 0.38, p < 0.0001) used in each study.

CONCLUSION

These results suggest that engaging in chronic exercise training (≥ 2 weeks) is associated with a decrease in leptin levels for individuals regardless of age and sex. However, a greater decrease in leptin occurred with a decreased percentage of body fat.

Effects of Aerobic Exercise Alone on Lipids in Healthy East Asians: A Systematic Review and Meta-Analysis

AIM

The purpose of the current work was to review the effects of regular aerobic exercise on serum lipid and lipoprotein levels in East Asians using meta-analysis.

METHODS

The randomized controlled trials analyzed involved healthy adults who were East Asians with a mean age ≥40 years, an exercise group that only performed regular aerobic exercise, and a control group that did not carry out exercise-related intervention; the trials indicated mean high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), or triglyceride (TG). The mean difference (MD) was defined as the difference (mean value at post-intervention in the exercise group－mean value at baseline in the exercise group)－(mean value at post-intervention in the control group－mean value at baseline in the control group) in HDL-C, LDL-C, TC, and TG and was calculated for each trial. The weighted MD was calculated with a random-effects model.

RESULTS

The meta-analysis examined 994 subjects in 25 studies. The weighted MD in HDL-C, TC, and TG improved significantly (HDL-C, 2.2 mg/dL; TC, －5.8 mg/dL; TG, －13.7 mg/dL). The weighted MD in HDL-C and TC contained significant heterogeneity (HDL-C, I²＝45.1%; TC, I²＝56.2%). When trials were limited to those involving moderate-intensity exercise (55%-69% of the maximum heart rate) or an exercise volume ≥150 min/week, the weighted MD in HDL-C, LDL-C, TC, and TG improved significantly and did not contain significant heterogeneity.

CONCLUSIONS

The findings suggest that the ideal form of exercise to improve lipid and lipoprotein levels in East Asians is exercise of moderate-intensity and in a volume ≥150 min/week.

Inhibitory Effects of Intranasal Administration of Insulin on Fat Oxidation during Exercise Are Diminished in Young Overweight Individuals

It remains unknown whether the high insulin (INS) levels in the brain affect fat oxidation during exercise. We examined the effects of the intranasal administration of INS, which increases the INS concentration in the cerebrospinal fluid when peripheral effects are lacking, on the maximum fat oxidation rate (maxFOR) and its intensity (FATmax) during exercise in 15 young normal-weight (N group) and eight young overweight (O group) individuals. On two separate days, either INS or placebo (PL) was randomly administered intranasally before a graded exercise test. Indirect calorimetry was used to assess maxFOR and FATmax during exercise. Blood INS and glucose levels did not change after INS administration. In the N group, maxFOR and FATmax were significantly smaller in the INS trial than in the PL trial. MaxFOR was significantly smaller in the O group than in the N group and was not influenced by INS administration. Exercise-induced elevation in blood epinephrine levels tended to be reduced by INS administration only in the N group. Intranasal INS administration reduces fat oxidation during exercise without any peripheral effects, possibly by suppressing sympathetic nerve activity. This inhibitory effect is diminished in overweight subjects, suggesting that cerebral insulin effects are attenuated in this population.

Inter-individual differences in weight change following exercise interventions: a systematic review and meta-analysis of randomized controlled trials

Previous reports of substantial inter-individual differences in weight change following an exercise intervention are often based solely on the observed responses in the intervention group. Therefore, we aimed to quantify the magnitude of inter-individual differences in exercise-mediated weight change. We synthesized randomized controlled trials (RCTs) of structured, supervised exercise interventions. Fourteen electronic databases were searched for relevant studies published up to March 2017. Search terms focused on structured training, RCTs and body weight. We then sifted these results for those RCTs (n = 12, 1500 participants) that included relevant comparator group data. Standard deviations (SDs) of weight change were extracted, thereby allowing the SD for true inter-individual differences in weight loss to be calculated for each study. Using a random effects meta-analysis, the pooled SD (95% CI) for true individual responses was 0.8 (-0.9 to 1.4) kg. The 95% prediction interval (based on 2SDs) for true inter-individual responses was -2.8 to 3.6 kg. The probability (% chance) that the true individual response variability would be clinically meaningful (>2.5 kg) in a future study in similar settings was 23% ('unlikely'). Therefore, we conclude that evidence is limited for the notion that there are clinically important individual differences in exercise-mediated weight change.

Water-Based Aerobic Training Successfully Improves Lipid Profile of Dyslipidemic Women: A Randomized Controlled Trial

PURPOSE

This study aimed to investigate the effects of water-based aerobic training on the lipid profile and lipoprotein lipase (LPL) levels in premenopausal women with dyslipidemia.

METHOD

Forty women were randomly assigned to: aquatic training (WA; n = 20) or a control group (CG; n = 20). The WA group underwent 12 weeks of water-based interval aerobic training twice a week at intensities ranging from 9 to 15 on the Borg Scale of Perceived Exertion. Total cholesterol (TC), triglycerides (TG), high- (HDL) and low- (LDL) density lipoprotein, TC/HDL ratio, LPL levels, and peak oxygen consumption (VO₂peak) were evaluated before and after 12 weeks in both groups.

RESULTS

The WA group elicited decreases in TC (9%; effect size [ES] = 0.69; 95% CI [0.05, 1.33]), LDL (16%; ES = 0.78; 95% CI [0.13, 1.42]), and the TC/HDL ratio (17%; ES = 1.13; 95% CI [0.46, 1.79]), as well as increases in VO₂peak (10%; ES = 0.64; 95% CI [0.002, 1.27]) and HDL (10%; ES = 0.28; 95% CI [-0.35. 0.90]), without significant changes in TG (ES = 0.16; 95% CI [-0.46, 1.79]) and LPL (ES = 0.36; 95% CI [-0.27, 0.98]) levels. In the CG, no statistically significant changes in any of these variables were found (TC, ES = 0.19, 95% CI [-0.43, 0.82]; LDL, ES = 0.22, 95% CI [-0.40, 0.85]; HDL, ES = 0.05, 95% CI [-0.57, 0.67]; TG, ES = 0.09, 95% CI [-0.53, 0.71]; TC/HDL ratio, ES = 0.20, 95% CI [-0.42, 0.82]; LPL, ES = 0.02, 95% CI [-0.60, 0.64]; VO₂peak, ES = 0.20, 95% CI [-0.42, 0.82]).

CONCLUSION

Water-based interval aerobic training positively affected the lipid profile in premenopausal dyslipidemic women.

Contextualising Maximal Fat Oxidation During Exercise: Determinants and Normative Values

Using a short-duration step protocol and continuous indirect calorimetry, whole-body rates of fat and carbohydrate oxidation can be estimated across a range of exercise workloads, along with the individual maximal rate of fat oxidation (MFO) and the exercise intensity at which MFO occurs (Fatmax). These variables appear to have implications both in sport and health contexts. After discussion of the key determinants of MFO and Fatmax that must be considered during laboratory measurement, the present review sought to synthesize existing data in order to contextualize individually measured fat oxidation values. Data collected in homogenous cohorts on cycle ergometers after an overnight fast was synthesized to produce normative values in given subject populations. These normative values might be used to contextualize individual measurements and define research cohorts according their capacity for fat oxidation during exercise. Pertinent directions for future research were identified.

In middle-aged and old obese patients, training intervention reduces leptin level: A meta-analysis

BACKGROUND

Leptin is one of the major adipokines in obesity that indicates the severity of fat accumulation. It is also an important etiological factor of consequent cardiometabolic and autoimmune disorders. Aging has been demonstrated to aggravate obesity and to induce leptin resistance and hyperleptinemia. Hyperleptinemia, on the other hand, may promote the development of age-related abnormalities. While major weight loss has been demonstrated to ameliorate hyperleptinemia, obese people show a poor tendency to achieve lasting success in this field. The question arises whether training intervention per se is able to reduce the level of this adipokine.

OBJECTIVES

We aimed to review the literature on the effects of training intervention on peripheral leptin level in obesity during aging, in order to evaluate the independent efficacy of this method. In the studies that were included in our analysis, changes of adiponectin levels (when present) were also evaluated.

DATA SOURCES

3481 records were identified through searching of PubMed, Embase and Cochrane Library Database. Altogether 19 articles were suitable for analyses.

STUDY ELIGIBILITY CRITERIA

Empirical research papers were eligible provided that they reported data of middle-aged or older (above 45 years of age) overweight or obese (body mass index above 25) individuals and included physical training intervention or at least fitness status of groups together with corresponding blood leptin values.

STATISTICAL METHODS

We used random effect models in each of the meta-analyses calculating with the DerSimonian and Laird weighting methods. I-squared indicator and Q test were performed to assess heterogeneity. To assess publication bias Egger's test was applied. In case of significant publication bias, the Duval and Tweedie's trim and fill algorithm was used.

RESULTS

Training intervention leads to a decrease in leptin level of middle-aged or older, overweight or obese male and female groups, even without major weight loss, indicated by unchanged serum adiponectin levels. Resistance training appears to be more efficient in reducing blood leptin level than aerobic training alone.

CONCLUSIONS

Physical training, especially resistance training successfully reduces hyperleptinemia even without diet or major weight loss.

Determination of the exercise intensity that elicits maximal fat oxidation in individuals with obesity

Maximal fat oxidation (MFO) and the exercise intensity that elicits MFO (FatMax) are commonly determined by indirect calorimetry during graded exercise tests in both obese and normal-weight individuals. However, no protocol has been validated in individuals with obesity. Thus, the aims were to develop a graded exercise protocol for determination of FatMax in individuals with obesity, and to test validity and inter-method reliability. Fat oxidation was assessed over a range of exercise intensities in 16 individuals (age: 28 (26-29) years; body mass index: 36 (35-38) kg·m-2; 95% confidence interval) on a cycle ergometer. The graded exercise protocol was validated against a short continuous exercise (SCE) protocol, in which FatMax was determined from fat oxidation at rest and during 10 min of continuous exercise at 35%, 50%, and 65% of maximal oxygen uptake. Intraclass and Pearson correlation coefficients between the protocols were 0.75 and 0.72 and within-subject coefficient of variation (CV) was 5 (3-7)%. A Bland-Altman plot revealed a bias of -3% points of maximal oxygen uptake (limits of agreement: -12 to 7). A tendency towards a systematic difference (p = 0.06) was observed, where FatMax occurred at 42 (40-44)% and 45 (43-47)% of maximal oxygen uptake with the graded and the SCE protocol, respectively. In conclusion, there was a high-excellent correlation and a low CV between the 2 protocols, suggesting that the graded exercise protocol has a high inter-method reliability. However, considerable intra-individual variation and a trend towards systematic difference between the protocols reveal that further optimization of the graded exercise protocol is needed to improve validity.