Effect of High-Intensity Interval Training on Total, Abdominal and Visceral Fat Mass: A Meta-Analysis

Training and Body Composition during Preparation for a 48-Hour Ultra-Marathon Race: A Case Study of a Master Athlete

Although the acute effects of ultra-endurance exercise on body composition have been well studied, limited information exists about the chronic adaptations of body composition to ultra-endurance training. The aim of the present study was to examine the day-by-day variation of training and body composition of a master athlete during the preparation for a 48-hour ultra-marathon race. For all training sessions (n = 73) before the race, the running distance, duration, and pace were recorded, and body mass, body fat (BF), body water (%), visceral fat, fat-free mass (FFM), four circumferences (i.e., waist, upper arm, thigh and calf), and eight skinfolds (i.e., chest, mid-axilla, triceps, subscapular, abdomen, iliac crest, thigh and calf) were measured accordingly in a 53-year-old experienced ultra-endurance athlete (body mass 80.1 kg, body height 177 cm, body mass index 25.6 kg·m⁻²). The main findings of the present study were that (a) the training plan of the ultra-endurance master athlete followed a periodization pattern with regard to exercise intensity and training volume, which increased over time, (b) the body mass, BF, and FFM decreased largely during the first 30 training sessions, and (c) the circumferences and skinfolds reflected the respective decrease in BF. The findings of this case study provided useful information about the variation of training and body composition during the preparation for an ultra-marathon race in a male master ultra-marathoner. The preparation for an ultra-endurance race seems to induce pronounced changes in body mass and body composition.

The effects of high-intensity interval training versus moderate-intensity continuous training on fat loss and cardiometabolic health in pediatric obesity: A protocol of systematic review and meta-analysis

BACKGROUND

The effects of aerobic exercise on fat loss and cardiometabolic health are well-documented, but it is unknown whether a high-intensity interval training (HIIT) elicit a greater health benefit in obese children and adolescents.

METHODS

Relevant studies in Pubmed, Web of Science, Embase, the Cochrane Library, EBSCO, and CNKI will be searched for studies with language restriction in English and Chinese, which were published from inception to December 1, 2018. Only randomized controlled trials of HIIT on pediatric obesity will be included, and observational studies, prospective cohort studies, and systematic reviews will be excluded. Two reviewers will independently screen the studies; risk of bias assessment and data extraction, and the results are inconsistent when discussed or resolved by a third reviewer. Data analysis and synthesis will be completed by the Revman 5.3 software and Stata 12.0 software. This study will be conducted by following the guideline of the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols.

CONCLUSION

This study will be conducted by previously published data, thus ethics approval is not required. This finding will be published in a related peer-reviewed journal and present it at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018111308.

The Physiology of Optimizing Health with a Focus on Exercise as Medicine

Physical inactivity is one of the leading health problems in the world. Strong epidemiological and clinical evidence demonstrates that exercise decreases the risk of more than 35 different disorders and that exercise should be prescribed as medicine for many chronic diseases. The physiology and molecular biology of exercise suggests that exercise activates multiple signaling pathways of major health importance. An anti-inflammatory environment is produced with each bout of exercise, and long-term anti-inflammatory effects are mediated via an effect on abdominal adiposity. There is, however, a need to close the gap between knowledge and practice and assure that basic research is translated, implemented, and anchored in society, leading to change of praxis and political statements. In order to make more people move, we need a true translational perspective on exercise as medicine, from molecular and physiological events to infrastructure and architecture, with direct implications for clinical practice and public health.

Repeated-sprint training under cyclic hypoxia improves body composition in healthy women

BACKGROUND

To investigate if the cyclic hypoxia exposure combined with repeat-sprints training would be more effective in reducing body fat of health women than the same protocols performed in normoxia.

METHODS

Twelve female volunteers were randomly divided into two groups: 1) repeated-sprint in hypoxia (RSH; N.=6; FiO2: 17.2%); and 2) repeated-sprint in normoxia (RSN; N.=6; FiO2: 20.9%). During 6 weeks, both groups undertook 30 seconds of all-out (130%Wmax) followed by 3 minutes of active recovery at 55-65%Wmax on a cycle ergometer. Anthropometric, body composition and biochemical parameters were assessed at baseline and after intervention.

RESULTS

RSH experimented a greater significant decrease of body mass index (P=0.017) and percentage of fat mass (P=0.05) respect to normoxia group. Total cholesterol of RSN experimented a significant (P=0.001) reduction (-12.66±14.35) compared with RSH (24.00±14.61).

CONCLUSIONS

Repeated-sprint training under normobaric cyclic hypoxia during 6-weeks could be a more effective prevention program because it causes a higher decrease in body mass index and fat mass compared with the same training in normoxic conditions in healthy women.

Effects of HIIT and MICT on cardiovascular risk factors in adults with overweight and/or obesity: A meta-analysis

Objective

The purpose of this study was to evaluate the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiovascular disease (CVD) risk factors in adults with overweight and obesity.

Methods

Twenty-two articles were included by searching six databases, the total number of subjects was 620 in these articles. Outcomes were synthesised using a random-effects meta-analysis of the Standardized mean difference (SMD) in CVD risk factors.

Results

HIIT and MICT resulted in statistically significant reductions in Weight, BMI, fat%, total cholesterol(TC), and improvement in VO_2max. Compared with MICT, subgroup of durations of HIIT training interval ≥2 min can significantly increase VO_2max (SMD = 0.444, 95% CI:0.037~0.851,P = 0.032), subgroup of energy expenditure of HIIT equal to MICT can significantly increase VO_2max (SMD = 0.399, 95% CI:0.106~0.692,P = 0.008).

Conclusions

HIIT appears to provide similar benefits to MICT for improving body composition, VO_2maxand TC, but HIIT spent less time than MICT by 9.7 min on one session. HIIT is superior to MICT in improving cardiopulmonary fitness when durations of HIIT training interval ≥2 min or energy expenditure of HIIT same as MICT. PROSPERO ID: CRD42016045835.

The influence of high-intensity interval training on anthropometric variables of adults with overweight or obesity: a systematic review and network meta-analysis

OBJECTIVE

The goal of this study was to evaluate the influence of high-intensity interval training (HIIT) on anthropometric variables in adults afflicted with overweight or obesity and to compare the effects with those of moderate-intensity continuous training.

METHODS

A computer literature search was performed for HIIT intervention studies that evaluated anthropometric variables in adults afflicted with overweight or obesity.

RESULTS

Of the 857 articles retrieved in the electronic search, 48 met the inclusion criteria. The analyses demonstrated that HIIT was effective in decreasing body mass (-1.45 kg [95% CI: -1.85 to -1.05 kg]), body mass index (-0.44 kg m^-2 [95% CI: -0.59 to -0.30 kg m^-2 ]), waist circumference (-2.3 cm [95% CI: -3.1 to -1.4 cm]), waist/hip ratio (-0.01 [95% CI: -0.02 to -0.00]), body fat percentage (-1.29% [95% CI: -1.70% to -0.87%]) and abdominal visceral fat area (-6.83 cm² [95% CI: -11.95 to -1.71 cm² ]). When considering equalization between the two methods (energy expenditure or workload matched), no differences were found in any measure except body mass (for which HIIT was superior).

CONCLUSIONS

High-intensity interval training and moderate-intensity continuous training results were similar, particularly when equalization between the two methods was considered. Thus, HIIT can be used as a secondary method for the treatment of obesity in adults.

The Impact of Different High-Intensity Interval Training Protocols on Body Composition and Physical Fitness in Healthy Young Adult Females

Although traditional high-intensity interval training (HIIT) has been effective in improving body composition and physical fitness, it is unclear how multimodal HIIT affects these variables. This study compared the differences between these two training programs on body composition and physical fitness in apparently healthy, nonobese young adult females. A total of 16 participants (mean age = 23 ± 5.08 years) completed a 12-week HIIT intervention with two treatment groups: rowing and multimodal. Immediately before and after the intervention, the following measures were assessed: body mass index (BMI), total body mass, waist circumference, waist-to-height ratio, total body fat %, visceral adipose tissue, lean mass, bone mineral outcomes, cardiovascular fitness, and muscular fitness. A general linear model with repeated measures was used to assess changes over time for the group as a whole, as well as between-group differences. For the group as a whole, there were significant decrease in total body fat % (p = 0.04) and significant increases in BMI (p = 0.015), total body mass (p = 0.003), lean mass (p < 0.001), bone mineral content (BMC) (p < 0.001), VO₂max (p = 0.01), broad jump (p = 0.001), squat endurance (p = 0.006), press (p < 0.001), back squat (p < 0.001), and deadlift (p < 0.001) one repetition maximum (1RM). The multimodal group (p < 0.001) increased deadlift 1RM significantly more than the rowing group (p = 0.002). HIIT can be an effective means for improving cardiovascular and muscular fitness, increasing lean mass and BMC, and thereby improving cardiometabolic as well as musculoskeletal health in nonobese females. Using a multimodal approach may give the added benefit of superior muscular strength increases.

Comparing Time Efficiency of Sprint vs. High-Intensity Interval Training in Reducing Abdominal Visceral Fat in Obese Young Women: A Randomized, Controlled Trial

Introduction: High-intensity interval training (HIIT) is an emerging lifestyle intervention strategy for controlling obesity. HIIT consisted of brief all-out supramaximal sprint intervals was termed as sprint interval training (SIT). This study was designed to examine the time-efficient characteristics of SIT in reducing abdominal visceral fat. Methods: A randomized controlled trial was conducted to compare the specific adaptations of SIT (80 × 6 s all-out cycle sprints interspersed with 9 s passive recovery) with those resulting from a HIIT regimen with training volume relatively higher (repeated 4 min bouts of cycling at 90% V˙ O_2max alternated with 3 min rest, until the work of 400KJ was achieved), and with those of nonexercising control counterparts (CON). Forty-six obese young women (body fat percentage ≥30) received either SIT (n = 16), HIIT (n = 16), or no training (n = 14), 3-4 sessions per week, for 12 weeks. The abdominal visceral fat area (AVFA) and abdominal subcutaneous fat area (ASFA) of the participants were measured through computed tomography scans pre-intervention and post-intervention. Total fat mass and the fat mass of the android, gynoid, and trunk regions were assessed through dual-energy X-ray absorptiometry. Results: Following the intervention, abdominal visceral and subcutaneous fat were reduced markedly (p < 0.05). The reduction in AVFA (-6.31, -9.7 cm²) was not different between SIT and HIIT (p > 0.05), while the reduction in ASFA (-17.4, -40.7 cm²) in SIT was less than that in HIIT (p < 0.05). Less reduction in the fat mass of the trunk (-1.2, -2.0 kg) region was also found in SIT, while the reductions in fat percentage (-1.9%, -2.0%), total fat mass (-2.0, -2.8 kg), and fat mass of the android (-0.2, -0.2 kg), and gynoid (-0.4, -0.3 kg) regions did not differ between the two regimes (p > 0.05). In contrast, the increase in V˙ O_2max was significant greater following the SIT than HIIT (p < 0.01). No variable changed in CON. Conclusion: Such findings suggest that the lower training load and exercise time commitments of the SIT regime could optimize the time-efficiency advantage of the traditional HIIT, facilitating the abdominal visceral fat reduction in obese young women.

The effect of aquatic high-intensity interval training on aerobic performance, strength and body composition in a non-athletic population: systematic review and meta-analysis

Objective:

In a non-athletic population, to (1) investigate the effectiveness of high-intensity interval training in an aquatic environment (A-HIIT) on aerobic performance, strength, and body composition and (2) report on safety of this approach.

Method:

A systematic search was undertaken of six databases until May 2018. Trials were eligible for inclusion if they compared the effect of A-HIIT in a non-athletic population with a control group that received no exercise training. Data were extracted independently by two reviewers and meta-analyses were undertaken using a random effects model to produce standardized mean difference (SMD) and 95% confidence intervals (CIs). Risk of bias was assessed using Cochrane’s risk of bias tool. All studies were graded using Physiotherapy Evidence Database (PEDro) and Consensus for Exercise Reporting Template (CERT) scales to determine quality of reporting.

Results:

Eight studies reported over 13 papers met study criteria ( n = 377). Compared with a control group, those who completed a program of A-HIIT demonstrated greater aerobic performance (SMD 0.69 (95% CI 0.39–0.98); I2 = 0%; n = 191) and lower limb muscle strength (SMD 0.30 (95% CI 0.04–0.56); I2 = 0%; n = 237). No differences were seen in measures of body composition or the number of adverse events. All studies were at risk of performance bias. The (mean ± SD) PEDro and CERT scores were 4.9 ± 1.5 and 15.1 ± 2.1, respectively.

Conclusion:

In a non-athletic population, A-HIIT was safe and may have improved aerobic performance and lower limb strength. The exercise interventions were well described and monitoring and reporting of exercise intensity in water was feasible.

Modulation of the renin-angiotensin system in white adipose tissue and skeletal muscle: focus on exercise training

Overactivation of the renin-angiotensin (Ang) system (RAS) increases the classical arm (Ang-converting enzyme (ACE)/Ang II/Ang type 1 receptor (AT1R)) to the detriment of the protective arm (ACE2/Ang 1-7/Mas receptor (MasR)). The components of the RAS are present locally in white adipose tissue (WAT) and skeletal muscle, which act co-operatively, through specific mediators, in response to pathophysiological changes. In WAT, up-regulation of the classical arm promotes lipogenesis and reduces lipolysis and adipogenesis, leading to adipocyte hypertrophy and lipid storage, which are related to insulin resistance and increased inflammation. In skeletal muscle, the classical arm promotes protein degradation and increases the inflammatory status and oxidative stress, leading to muscle wasting. Conversely, the protective arm plays a counter-regulatory role by opposing the effect of Ang II. The accumulation of adipose tissue and muscle mass loss is associated with a higher risk of morbidity and mortality, which could be related, in part, to overactivation of the RAS. On the other hand, exercise training (ExT) shifts the balance of the RAS towards the protective arm, promoting the inhibition of the classical arm in parallel with the stimulation of the protective arm. Thus, fat mobilization and maintenance of muscle mass and function are facilitated. However, the mechanisms underlying exercise-induced changes in the RAS remain unclear. In this review, we present the RAS as a key mechanism of WAT and skeletal muscle metabolic dysfunction. Furthermore, we discuss the interaction between the RAS and exercise and the possible underlying mechanisms of the health-related aspects of ExT.

Effects of Aerobic Exercise on Metabolic Syndrome, Cardiorespiratory Fitness, and Symptoms in Schizophrenia Include Decreased Mortality

Schizophrenia is a severe psychiatric disorder with a lifetime prevalence of about 1%. People with schizophrenia have a 4-fold higher prevalence of metabolic syndrome than the general population, mainly because of antipsychotic treatment but perhaps also because of decreased physical activity. Metabolic syndrome is a risk factor for cardiovascular diseases, and the risk of these diseases is 2- to 3-fold higher in schizophrenia patients than in the general population. The suicide risk is also higher in schizophrenia, partly as a result of depression, positive, and cognitive symptoms of the disease. The higher suicide rate and higher rate of cardiac mortality, a consequence of the increased prevalance of cardiovascular diseases, contribute to the reduced life expectancy, which is up to 20 years lower than in the general population. Regular physical activity, especially in combination with psychosocial and dietary interventions, can improve parameters of the metabolic syndrome and cardiorespiratory fitness. Furthermore, aerobic exercise has been shown to improve cognitive deficits; total symptom severity, including positive and negative symptoms; depression; quality of life; and global functioning. High-intensity interval endurance training is a feasible and effective way to improve cardiorespiratory fitness and metabolic parameters and has been established as such in somatic disorders. It may have more beneficial effects on the metabolic state than more moderate and continuous endurance training methods, but to date it has not been investigated in schizophrenia patients in controlled, randomized trials. This review discusses physical training methods to improve cardiorespiratory fitness and reduce metabolic syndrome risk factors and symptoms in schizophrenia patients. The results of studies and future high-quality clinical trials are expected to lead to the development of an evidence-based physical training program for patients that includes practical recommendations, such as the optimal length and type of aerobic exercise programs and the ideal combination of exercise, psychoeducation, and individual weight management sessions.