Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate

Tensiomyography: from muscle assessment to talent identification tool

Introduction: Tensiomyography (TMG) is a non-invasive and cost-effective tool that is gaining popularity in fields such as sports science, physical therapy, and medicine. In this narrative review, we examine the different applications of TMG and its strengths and limitations, including its use as a tool for sport talent identification and development. Methods: In the course of crafting this narrative review, an exhaustive literature search was carried out. Our exploration spanned several renowned scientific databases, such as PubMed, Scopus, Web of Science, and ResearchGate. The materials we sourced for our review included a broad spectrum of both experimental and non-experimental articles, all focusing on TMG. The experimental articles featured varied research designs including randomized controlled trials, quasi-experiments, as well as pre-post studies. As for the non-experimental articles, they encompassed a mix of case-control, cross-sectional, and cohort studies. Importantly, all articles included in our review were written in English and had been published in peer-reviewed journals. The assortment of studies considered provided a holistic view of the existing body of knowledge on TMG, and formed the basis of our comprehensive narrative review. Results: A total of 34 studies were included in the review, organized into three sections: 1) assessing muscle contractile properties of young athletes, 2) using TMG in the talent identification and development process and 3) Future research and perspectives. According to data presented here, the most consistent TMG parameters for determining muscle contractile properties are radial muscle belly displacement, contraction time, and delay time. Biopsy findings from the vastus lateralis (VL) confirmed TMG as a valid tool for estimating the ratio of myosin heavy chain (%MHC-I). Conclusion: TMGs ability to estimate the ratio of %MHC-I has the potential to aid in the selection of athletes with the muscle characteristics best suited for a particular sport, eliminating the need for more invasive procedures. However, more research is warranted to fully understand TMG's potential and its reliability when used with young athletes. Importantly, the use of TMG technology in this process can positively impact health status, reducing the frequency and severity of injuries and the duration of recovery, and subsequently can reduce drop out rates among youth athletes. Future studies should look at twin youth athletes, as a model capable of discriminating between the influence of hereditary factors vs. environmental factors, in therms of muscle contractility and TMG's potential for instance.

Increased contribution of KCa channels to muscle contraction induced vascular and blood flow responses in sedentary and exercise trained ZFDM rats

KEY POINTS

Microvascular dysfunction in type 2 diabetes impairs blood flow redistribution during exercise and limits the performance of skeletal muscle and may cause early fatigability. Endothelium-dependent hyperpolarization (EDH), which mediates vasodilation in resistance arteries is known to be depressed in animals with diabetes. Here we report that low-intensity exercise training in ZFDM rats increased KCa channel-derived component in the vasodilator responses to muscle contraction than in sedentary rats, partly due to the increase in KCNN3 expression. These results suggest that low-intensity exercise training improves blood flow redistribution in contracting skeletal muscle in metabolic disease with diabetes via upregulation of EDH.

ABSTRACT

In resistance arteries, endothelium-dependent hyperpolarization (EDH) mediated vasodilation is depressed in diabetes. We hypothesized that downregulation of KCa channel derived EDH reduces exercise-induced vasodilation and blood flow redistribution in diabetes. To test this hypothesis, we evaluated vascular function in response to hindlimb muscle contraction, and the contribution of KCa channels in anaesthetised ZFDM, metabolic disease rats with type 2 diabetes. We also tested whether exercise training ameliorated the vascular response. Using in vivo microangiography, the hindlimb vasculature was visualized before and after rhythmic muscle contraction (0.5 s tetanus every 3 sec, 20 times) evoked by sciatic nerve stimulation (40 Hz). Femoral blood flow of the contracting hindlimb was simultaneously measured by an ultrasonic flowmeter. The contribution of KCa channels was investigated in the presence and absence of apamin and charybdotoxin. We found that vascular and blood flow responses to muscle contraction were significantly impaired at the level of small artery segments in ZFDM fa/fa rats compared to its lean control fa/+ rats. The contribution of KCa channels was also smaller in fa/fa than in fa/+ rats. Low-intensity exercise training for 12 weeks in fa/fa rats demonstrated minor changes in the vascular and blood flow response to muscle contraction. However, KCa-derived component in the response to muscle contraction was much greater in exercise trained than in sedentary fa/fa rats. These data suggest that exercise training increases the contribution of KCa channels among endothelium-dependent vasodilatory mechanisms to maintain vascular and blood flow responses to muscle contraction in this metabolic disease rat model. Abstract figure legend Low-intensity exercise training in ZFDM, metabolic disease rats with type 2 diabetes increases KCa channel-derived component of endothelium-dependent hyperpolarization in the vascular and blood flow responses to skeletal muscle contraction than the responses in sedentary rats, partly due to upregulation of KCNN3 protein expression. This article is protected by copyright. All rights reserved.

Association of energy availability with resting metabolic rates in competitive female teenage runners: a cross-sectional study

Background

Resting metabolic rate (RMR) has been examined as a proxy for low energy availability (EA). Previous studies have been limited to adult athletes, despite the serious health consequences of low EA, particularly during adolescence. This study aimed to explore the relationship between RMR and EA in competitive teenage girl runners.

Methods

Eighteen girl runners (mean ± standard-deviation; age, 16.8 ± 0.9 years; body mass, 45.6 ± 5.2 kg, %fat, 13.5 ± 4.2 %) in the same competitive high-school team were evaluated. Each runner was asked to report dietary records with photos and training logs for seven days. Energy intake (EI) was assessed by Registered Dietitian Nutritionists. The runners were evaluated on a treadmill with an indirect calorimeter to yield individual prediction equations for oxygen consumption using running velocity and heart rate (HR). Exercise energy expenditure (EEE) was calculated by the equations based on training logs and HR. Daily EA was calculated by subtracting EEE from EI. The daily means of these variables were calculated. RMR was measured early in the morning by whole-room calorimetry after overnight sleep on concluding the final day of the seven-day assessment. The ratio of measured RMR to predicted RMR (RMR ratio) was calculated by race, age, sex-specific formulae, and Cunningham’s equation. Body composition was measured using dual-energy X-ray absorptiometry. Bivariate correlation analyses were used to examine the relationship between variables.

Results

RMR, EI, EEE, and EA were 26.9 ± 2.4, 56.8 ± 15.2, 21.7 ± 5.9, and 35.0 ± 15.0 kcal⋅kg⁻¹ FFM⋅d⁻¹, respectively. RMR reduced linearly with statistical significance, while EA decreased to a threshold level (30 kcal⋅kg⁻¹ FFM⋅d⁻¹) (r= 0.58, p= 0.048). Further reduction in RMR was not observed when EA fell below the threshold. There was no significant correlation between RMR ratios and EA, irrespective of the prediction formulae used.

Conclusions

These results suggest that RMR does not reduce with a decrease in EA among highly competitive and lean teenage girl runners. RMR remains disproportionally higher than expected in low EA states. Free-living teenage girl runners with low EA should be cautiously identified using RMR as a proxy for EA change.

The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis

BACKGROUND

Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown.

OBJECTIVES

This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

We searched five electronic databases up to January 2021.

ELIGIBILITY CRITERIA

We included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults.

ANALYSIS

We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components.

RESULTS

From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6-15). Compared to the control, resistance training reduced body fat percentage by - 1.46% (95% confidence interval - 1.78 to - 1.14, p < 0.0001), body fat mass by - 0.55 kg (95% confidence interval - 0.75 to - 0.34, p < 0.0001) and visceral fat by a standardised mean difference of - 0.49 (95% confidence interval - 0.87 to - 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults.

STUDY REGISTRATION

osf.io/hsk32.

The role of age in the physiological adaptations and psychological responses in bikini-physique competitor contest preparation: a case series

The increased popularity of the bikini-physique competitions has not translated to greater research identifying the influence of age on adaptations during contest preparation. The purpose of this case series was to observe how age may influence the adaptations normally seen during preparation and the exploration of newer protocols to address adaptations more relative to the judging standards. Over a 16-week pre-contest preparation, a 32-y bikini competitor (BC) and 44-y master's bikini competitor (MBC) visited the laboratory bi-weekly to observe changes in body fat mass (BF), lean body mass (LBM), bone mineral density (BMD), total body water (TBW); exploratory measures of deltoid cross-sectional area (DeltCSA), gluteus maximus muscle thickness (GMMT), and subcutaneous adipose tissue thickness (SAT); reproductive hormones estradiol (E2), luteinizing hormone (LH), and energy balance hormones triiodothyronine (T3), leptin and ghrelin; hydration status during contest preparation and the week of competition; resting metabolic rate (RMR); psychometric data related to perceived anxiety, stress, and body image were assessed. No differences between BC and MBC were observed in BF, LBM, BMD, and TBW. Both competitors showed a small loss in LBM. Both BC and MBC showed a contrasting increase in DeltCSA and a loss in GMMT. MBC showed to be slightly more dehydrated (1.025 vs 1.021 g·mL- 1) than BC. Both competitors maintained a euhydration status the day of the competition. No time differences were found between BC and MBC during RMR. BC showed a higher mean difference RMR compared to MBC (2.66 ± 0.75 kcal·kgLBM- 1·d- 1). MBC showed a higher mean difference in LH concentration (84.6 ± 6.01 IU·L- 1), which may be explained by perimenopausal status. MBC had a higher mean difference concentration of leptin (2.51 ± 0.24 ng·mL- 1·kgFM- 1), which was unperturbed by fat loss may be interrelated LH. BC self-reported a higher mean energy intake (15.07 ± 3.43 kcal·kgLBM- 1·d- 1) and higher aerobic training volume (93.26 ± 40.68 min·d). BC and MBC showed similar composition changes, slightly differing metabolic rates, and differing hormonal LH and leptin responses. This finding is in contrast to previous work showing both LH inhibition and leptin diurnal disturbance in younger, female athletes with low energy availability. The exploratory measures may have some benefit for bikini-physique competitors related to the judging criteria. Age did not seem to play a role in contest preparation adaptations.

The Effects of Very Low Energy Diets and Low Energy Diets with Exercise Training on Skeletal Muscle Mass: A Narrative Review

In recent years, very-low-energy diets (VLEDs) have been recognised as a viable strategy for improving the extent of weight loss and cardio-metabolic outcomes in people who are either overweight or obese. However, concerns exist regarding the reductions in lean body mass (LBM) during VLEDs, particularly in vulnerable demographic groups, such as middle-aged and older adults already prone to developing sarcopenia. Sarcopenia is itself associated with multiple adverse outcomes, including frailty, cardio-metabolic deterioration and increased mortality. Therefore, a number of studies investigating strategies to ameliorate this detrimental effect of VLEDs have attempted to address this concern. This narrative review explores the potential benefits and limitations of exercise and/or protein supplementation for LBM retention during VLEDs based on the available evidence. Current studies suggest that both protein supplementation and exercise training may result in improved LBM retention (and skeletal muscle function) during VLEDs. However, uncertainty remains concerning the interactions between intervention types, based on discordant outcomes reported in the literature and the heterogeneity of exercise modalities in achieving this particular outcome.

Effects of single bout resistance exercise on glucose levels, insulin action, and cardiovascular risk in type 2 diabetes: A narrative review

AIMS

Previous studies have reported beneficial effects of chronic resistance exercise in the prevention and treatment of type 2 diabetes. To clarify potential modulators of acute responses to resistance exercise, we reviewed the literature to determine the effects of a single bout of resistance exercise on cardiometabolic risk factors in type 2 diabetes.

METHODS

Pubmed and Embase were searched for studies investigating the effects of single bouts of resistance exercise on glucose and insulin levels, and cardiovascular disease risk in people with diabetes. Fourteen reports were identified and reviewed to formulate evidence-based resistance exercise prescription recommendations.

RESULTS

Glucose and insulin levels appear to decrease with resistance exercise with effects lasting up to 24 and 18 h, respectively. Bouts of resistance exercise may outperform aerobic exercise in reducing ambulatory blood pressure, with effects lasting up to 24 h. Moreover, resistance exercise after rather than before a meal may be more effective in reducing glucose, insulin, and triacylglycerol levels. However, reducing injectable insulin dosage prior to resistance exercise may blunt its favorable effects on glucose levels.

CONCLUSIONS

This review suggests that a single bout of resistance exercise may be effective for acutely improving cardiometabolic markers in people with diabetes.

Can Energetic Capacity Help Explain Why Physical Activity Reduces Cancer Risk?

Increased physical activity reduces cancer risk in humans, but why this whole-organism attribute reduces cancer remains unclear. Active individuals tend to have high capacity to generate energy on a sustained basis, which in turn can permit greater immune responses crucial for fighting emerging neoplasia. Thus, we suggest energetic capacity as a potential mechanism to explain the activity-cancer link, given that humans are intrinsically (not externally) energy limited. Human and rodent studies show that individuals with high energetic capacity mount greater immune responses and have lower cancer incidence; these trends persist after controlling for actual physical activity, supporting a direct role of energetic capacity. If true, exercise efforts might best target those that increase one's energetic capacity, which may be both individual and exercise specific.

Resistance Training Induces Antiatherogenic Effects on Metabolomic Pathways

INTRODUCTION

Arising evidence suggests that resistance training has the potential to induce beneficial modulation of biomarker profile. To date, however, only immediate responses to resistance training have been investigated using high-throughput metabolomics whereas the effects of chronic resistance training on biomarker profile have not been studied in detail.

METHODS

A total of 86 recreationally active healthy men without previous systematic resistance training background were allocated into (i) a resistance training (RT) group (n = 68; age, 33 ± 7 yr; body mass index, 28 ± 3 kg·m) and (ii) a non-RT group (n = 18; age, 31 ± 4 yr; body mass index, 27 ± 3 kg·m). Blood samples were collected at baseline (PRE), after 4 wk (POST-4wk), and after 16 wk of resistance training intervention (POST-16wk), as well as baseline and after the non-RT period (20-24 wk). Nuclear magnetic resonance-metabolome platform was used to determine metabolomic responses to chronic resistance training.

RESULTS

Overall, the resistance training intervention resulted in favorable alterations (P < 0.05) in body composition with increased levels of lean mass (~2.8%), decreased levels of android (~9.6%), and total fat mass (~7.5%). These changes in body composition were accompanied by antiatherogenic alterations in serum metabolome profile (false discovery rate < 0.05) as reductions in non-high-density lipoprotein cholesterol (e.g., free cholesterol, remnant cholesterol, intermediate-density lipoprotein cholesterols, low-density lipoprotein cholesterols) and related apolipoprotein B, and increments in conjugated linoleic fatty acids levels were observed. Individuals with the poorest baseline status (i.e., body composition, metabolome profile) benefitted the most from the resistance training intervention.

CONCLUSIONS

In conclusion, resistance training improves cardiometabolic risk factors and serum metabolome even in previously healthy young men. Thus, suggesting attenuated risk for future cardiovascular disease.

Plasma retinol-binding protein-4 and tumor necrosis factor-α are reduced in postmenopausal women after combination of different intensities of circuit resistance training and Zataria supplementation

Purpose

Zataria is a plant with anti-inflammatory properties, which has been used for the treatment of many diseases. This study investigated the effect of different intensities of circuit resistance training and Zataria supplementation on plasma retinol-binding protein-4 (RBP-4) and tumor necrosis factor-α (TNF-α) in postmenopausal women.

Methods

Seventy-two postmenopausal women were divided on randomized order into six groups: Control (McGinley and Bishop in J Appl Physiol 121(6):1290-1305, 2016), Training 35% (T35%), Training 55% (T55%), Zataria (Özgünen et al. in Scand J Med Sci Sports 20:140-147, 2010), Zataria/Training 35% (ZT35%), and Zataria/Training 55% (ZT55%). Resist-ance training program included 12 exercise stations (each: 30 s, intensity: 35% and 55% of 1-RM) for 8 weeks (3 sessions/week). Daily (500 mg) Zataria was used after breakfast by participants in ZG, ZT35%, and ZT55% groups. Blood samples were taken 48 h before and after the first and last sessions of training.

Results

After the training period the percentage of body fat decreased significantly (P < 0.001) in all trained groups, whereas muscle mass increased significantly (P < 0.01) only in T55% and ZT55% groups. A significant decrease was observed for RBP-4 values (P < 0.05) after training in all groups except for ZG and CG. Also, RBP-4 was significantly lower (P < 0.05) in all groups as compared to CG at the post-test except for ZG. Moreover, significantly lower values (P < 0.05) were found in T55%, ZT35%, and ZT55% as compared to ZG in post-intervention. TNF-α values decreased significantly (P < 0.05) at the post-test as compared to pre-intervention in ZT35% and ZT55%. Also, TNF-α was significantly lower (P < 0.05) in ZT55% compared to CG and T35% in post-test.

Conclusions

The results demonstrate clearly that in postmenopausal women, circuit resistance training both at low and moderate intensities cause a greater reduction in RBP-4 and TNF-α when Zataria is supplemented in the diet during training.

Intermittent Dieting: Theoretical Considerations for the Athlete

Athletes utilise numerous strategies to reduce body weight or body fat prior to competition. The traditional approach requires continuous energy restriction (CER) for the entire weight loss phase (typically days to weeks). However, there is some suggestion that intermittent energy restriction (IER), which involves alternating periods of energy restriction with periods of greater energy intake (referred to as ‘refeeds’ or ‘diet breaks’) may result in superior weight loss outcomes than CER. This may be due to refeed periods causing transitory restoration of energy balance. Some studies indicate that intermittent periods of energy balance during energy restriction attenuate some of the adaptive responses that resist the continuation of weight and fat loss. While IER—like CER—is known to effectively reduce body fat in non-athletes, evidence for effectiveness of IER in athletic populations is lacking. This review provides theoretical considerations for successful body composition adjustment using IER, with discussion of how the limited existing evidence can be cautiously applied in athlete practice.

Effect of a Whey Protein Supplement on Preservation of Fat Free Mass in Overweight and Obese Individuals on an Energy Restricted Very Low Caloric Diet

The obesity epidemic has caused a widespread interest in strategies to achieve a healthy "high quality" weight loss, where excess fat is lost, while fat free mass (FFM) is preserved. In this study, we aimed to examine the effect of whey protein supplementation given before night sleep on FFM preservation during a 4-week (wk) period on a very low caloric diet (VLCD). Twenty-nine obese subjects (body mass index (BMI) > 28 kg/m²) completed a 4-week intervention including a VLCD and a walking program (30 min walking × 5 times per week). Subjects were randomly assigned to either control (CON, n = 15) or a whey protein supplement (PRO, 0.4 g protein/kg/day, n = 14), ingested before bedtime. Body composition (dual-energy X-ray absorptiometry, DXA), blood analysis and physical test were performed pre and post intervention. We measured nitrogen excretion in three 24 h urine collections (Day 0, 7 and 28) to assess nitrogen balance. Changes in nitrogen balance (NB) after 7 and 28 days was different between treatment groups (interaction p < 0.05). PRO was in NB after 7 days and in positive NB at day 28. In contrast, CON was in negative NB at day 7, but in NB at day 28. Nevertheless, no significant group differences were observed in the change in pre- and post-FFM measurements (-2.5 kg, [95% CI: 1.9; 3.1], p = 0.65). In conclusion, ingestion of a whey protein supplement before bedtime during a 4-week period on a VLCD improved nitrogen balance, but did not lead to any significant improvement in the quality of the weight loss in regard to observed changes in body composition and health parameters compared with controls.

Continuous versus intermittent moderate energy restriction for increased fat mass loss and fat free mass retention in adult athletes: protocol for a randomised controlled trial-the ICECAP trial (Intermittent versus Continuous Energy restriction Compared in an Athlete Population)

Introduction

Reducing fat mass (FM) while retaining fat free mass (FFM) is a common goal of athletes. Evidence suggests that some-but not all-forms of intermittent energy restriction (IER) may be superior to the conventional method of continuous energy restriction (CER) for people with excess body fat that are sedentary, by reducing some of the adaptive responses to ER. However, it is yet to be established whether this dietary approach is effective for athletes.

Methods and analysis

A single-blind, parallel group, randomised controlled trial with a 1:1 allocation ratio is proposed. Sixty healthy athletes aged ≥18 years will be recruited from local sporting facilities and randomised to an intervention of either moderate CER (mCER) or moderate IER (mIER). Both interventions will consist of 12 weeks of moderate ER, plus 3 weeks in energy balance (EB). The mCER intervention will entail 12 weeks of continuous moderate ER, followed by 3 weeks in EB. The mIER intervention will entail 12 weeks of moderate ER, administered as 4×3 week blocks of moderate ER, interspersed with 3×1 week blocks of EB. The co-primary outcomes are changes in FM and FFM after 12 weeks of moderate ER. Secondary outcomes will be changes in FM and FFM at 15 weeks after intervention commencement, as well as muscle performance, physical activity, sleep quality, changes in resting energy expenditure, subjective drive to eat, circulating concentrations of appetite-regulating hormones, mood states and diet acceptability.

Trial registration

ACTRN12618000638235p.

Effects of alternate day calorie restriction and exercise on cardio-metabolic risk factors in overweight and obese adults: an exploratory randomized controlled study

BACKGROUND

It has been recognized that alternate day calorie restriction (ADCR) or exercise has positive effects on cardio-metabolic risk factors. It is unclear whether the combined effect of ADCR and exercise (aerobic + resistance training) influences risk. We investigated effects of an 8-week ADCR and exercise program (aerobic + resistance training) on cardio-metabolic risk factors in overweight and obese adults.

METHODS

This study randomized 45 overweight or obese but healthy adults (F = 26, M = 19; aged about 32 to 40 years) into 4 groups: ADCR (n = 13), exercise (n = 10), exercise plus ADCR (n = 12), and control (n = 10) for 8 weeks. Body composition, blood lipids profile, and insulin resistance were measured. The intention to treat (ITT) method was used to analyze all participants that were randomized.

RESULTS

A total of 35 participants completed the trial (78%). Body weight, body mass index, waist circumference, fat mass and percent body fat were reduced in the exercise plus ADCR group (- 3.3 ± 2.4 kg, p < 0.01; - 1.3 ± 1.0 kg/m2, p < 0.01; - 4.1 ± 3.9 cm, p < 0.01; - 2.7 ± 2.0 kg, p < 0.01; - 2. 5 ± 2.2%, p < 0.01). Insulin, glucose, homeostasis model assessment insulin resistance and triglyceride (- 2.9 ± 4.1 μIU/ml, p < 0.05; - 10.9 ± 16.9 mg/dl, p < 0.05; - 0.9 ± 1.3, p < 0.05; - 43.8 ± 41.9 mg/dl, p < 0.01) decreased in the exercise plus ADCR group only.

CONCLUSIONS

ADCR and exercise both proved to be beneficial, but the combined intervention was most effective at inducing beneficial changes in body weight, body composition, glucose, insulin, insulin resistance and triglyceride in overweight and obese adults.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03652532 , Registered August 28, 2018, 'retrospectively registered'.

Physiological implications of preparing for a natural male bodybuilding competition

This study aimed to describe the body composition and physiological changes which take place during the in-season and recovery periods of a group of natural bodybuilders. Natural male bodybuilders (n = 9) were assessed 16 (PRE16), 8 (PRE8), and 1 (PRE1) week(s) before, and 4 (POST4) weeks after a bodybuilding competition. Assessments included body composition, resting metabolic rate (RMR), serum hormones, and 7-day weighed food and training diaries. Change in parameters was assessed using repeated-measures analysis of variance. Dietary protein intake remained high throughout the study period (2.8-3.1 g kg^-1 d^-1). Fat mass (FM) was significantly reduced from PRE16 to PRE1 (8.8 ± 3.1 vs. 5.3 ± 2.4 kg, P < .01). There was a small decrease in lean mass (LM) from PRE8 to PRE1 (71.8 ± 9.1 vs. 70.9 ± 9.1 kg, P < .05). No changes in RMR were observed (P > .05). Large reductions in total and free testosterone (16.4 ± 4.4 vs. 10.1 ± 3.6 nmol L^-1, P < .05; 229.3 ± 72.4 vs. 116.8 ± 76.9 pmol L^-1, P < .05), and insulin-like growth factor-1 (IGF-1) (27.0 ± 7.7 vs. 19.9 ± 7.6 nmol L^-1, P < .05) occurred between PRE16 and PRE1. LM and IGF-1 increased from PRE1 to POST4 (70.9 ± 9.1 vs. 72.5 ± 8.5 kg, P < .05; 19.9 ± 7.6 vs. 25.4 ± 9.3 nmol L^-1, P < .05). Despite substantial reductions in FM, participants maintained almost all of their LM. The reduction in anabolic hormone concentration is likely attributable to the prolonged negative energy balance, despite a high dietary protein intake.

Resistance training during a 12-week protein supplemented VLCD treatment enhances weight-loss outcomes in obese patients

BACKGROUND

This investigation evaluated the efficacy by which resistance training enhances body composition, metabolic, and functional outcomes for obese patients undergoing a 12-week medically supervised hypocaloric treatment.

METHODS

This was a single-blind, randomized, parallel-group prospective trial. Morbidly obese patients were prescribed a 12-week proprietary very low calorie diet (VLCD) treatment (Optifast^®) with supplemental protein (1120 kcals/day) and were placed in one of two groups for 14 weeks: 1) Standard Treatment Control (CON) (n = 5) or 2) Resistance Training (RT) (n = 6). Both groups underwent a pedometer-based walking program; however only RT performed resistance training 3 days/week for 12 weeks. Body composition, resting energy expenditure (REE), neuromuscular function, and serum biomarkers were measured at weeks 0, 6, and 13.

RESULTS

Both groups exhibited a significant loss of total body mass (TBM) (CON: -19.4 ± 2.3 kg, p = 0.0009 vs. RT: -15.8 ± 1.5 kg, p = 0.0002) and fat mass (FM) (CON: -14.7 ± 1.8 kg, p = 0.0002 vs. RT: -15.1 ± 2.1 kg, p = 0.0002) with no group differences. CON lost 4.6 ± 0.8 kg (p = 0.004) of lean mass (LM) while RT demonstrated no changes. Group differences were found for the relative proportion of total weight-loss due to FM-loss (CON: 75.6 ± 3.4% vs. RT: 96.0 ± 6.0%, p = 0.03) and LM-loss (CON: 24.4 ± 3.2% vs. RT: 4.0 ± 6.5%, p = 0.03). CON demonstrated a 328.6 ± 72.7 kcal/day (-14.3 ± 2.4%) (p = 0.02) decrease in REE while RT exhibited a non-significant decrease of 4.6 ± 1.6% (p = 0.78). RT demonstrated greater improvements in all measures of contractile function and strength when compared to CON (p < 0.05). At post-treatment, RT exhibited greater serum free fatty acids (p = 0.01), glycerol (p = 0.003), and β-hydroxybutyrate (p = 0.005) than CON.

CONCLUSION

Resistance training was advantageous for weight-loss composition by preservation of LM without compromising overall weight- or fat-loss in morbidly obese men and women undergoing a protein supplemented VLCD. These changes accompanied positive adaptations for resting metabolism and muscular function.

A mathematical model of the effects of resistance exercise-induced muscle hypertrophy on body composition

PURPOSE

Current diet and exercise methods used to maintain or improve body composition often have poor long-term outcomes. We hypothesize that resistance exercise (RE) should aid in the maintenance of a healthy body composition by preserving lean mass (LM) and metabolic rate.

METHOD

We extended a previously developed energy balance model of human metabolism to include muscle hypertrophy in response to RE. We first fit model parameters to a hypothetical individual to simulate an RE program and then compared the effects of a hypocaloric diet only to the diet with either cardiovascular exercise (CE) or RE. We then simulated a cohort of individuals with different responses to RE by varying the parameters controlling it using Latin Hypercube Sampling (LHS). Finally, we fit the model to mean data from an elderly population on an RE program.

CONCLUSION

The model is able to reproduce the time course of change in LM in response to RE and can be used to generate a simulated cohort for in silico clinical studies. Simulations suggest that the additional LM generated by RE may shift the body composition to a healthier state.

International society of sports nutrition position stand: diets and body composition

Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of diet types (macronutrient composition; eating styles) and their influence on body composition. The ISSN has concluded the following. 1) There is a multitude of diet types and eating styles, whereby numerous subtypes fall under each major dietary archetype. 2) All body composition assessment methods have strengths and limitations. 3) Diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit may be imposed. Slower rates of weight loss can better preserve lean mass (LM) in leaner subjects. 4) Diets focused primarily on accruing LM are driven by a sustained caloric surplus to facilitate anabolic processes and support increasing resistance-training demands. The composition and magnitude of the surplus, as well as training status of the subjects can influence the nature of the gains. 5) A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition. 6) Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may result in improved body composition. Higher protein intakes (2.3–3.1 g/kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects under hypocaloric conditions. Emerging research on very high protein intakes (>3 g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects. 7) The collective body of intermittent caloric restriction research demonstrates no significant advantage over daily caloric restriction for improving body composition. 8) The long-term success of a diet depends upon compliance and suppression or circumvention of mitigating factors such as adaptive thermogenesis. 9) There is a paucity of research on women and older populations, as well as a wide range of untapped permutations of feeding frequency and macronutrient distribution at various energetic balances combined with training. Behavioral and lifestyle modification strategies are still poorly researched areas of weight management.

The impact of duration on effectiveness of exercise, the implication for periodization of training and goal setting for individuals who are overfat, a meta-analysis

Given the assumption that all methods of exercise, e.g., endurance (ET), resistance (RT), or combination of both (E+R), can induce a beneficial effect size (ES) for changes in body composition and health status of individuals who are overfat. Thus the aim and purpose of this study is to evaluate the current body of knowledge to address the question as to the impact that the duration of exercise has on its relative effectiveness for inducing health and body compositional changes in individuals who are overfat to assist with developing periodized exercise protocols and establishing short and long term goals. A tiered meta-analysis of 92-studies and 200-exercise groupings were used for establishing pooled ES within and between groupings based on the increments of 4-week of duration and study designs of ≤8, 9-16, 17-23, 24-36, and ≥36 weeks. Analysis based on random-effect of response indicates a continuum of effectiveness within and between ET, RT and E+R based on duration. Where beneficial effectiveness is not indicated for any measures until after 8-weeks of continuous training with progressive effectiveness being noted in changes to cardiorespiratory fitness, inflammatory cytokines, and alteration of metabolic status from 12-weeks through 32-weeks of continuous training. Results indicate a greater ES for RT and E+R versus ET early in intervention that equalizes with longer durations. Supporting the use of RT and E+R within a periodized program. And secondarily, goals should be established first on performance gains and second body composition or health status modifications for the individual who is overfat.

Influence of Relative Strength on Functional Independence of Patients With Spinal Cord Injury

OBJECTIVE

To investigate the influence of strength values and fat mass on functional independence of men with different spinal cord injury (SCI) levels.

DESIGN

Cross-sectional study.

SETTING

Hospital network.

PARTICIPANTS

Men with SCI (N=45).

INTERVENTIONS

Subjects were assessed in functional independence scales, a 1 repetition maximum (1RM) test, and body composition to detect absolute and relative strength: 1RM divided by body mass (BM) and lean body mass (LBM), respectively.

MAIN OUTCOME MEASURES

Stepwise multiple regression analysis was used to verify the influence of predictors on functional independence (FIM and Spinal Cord Independence Measure [SCIM] scale and subscales). Receiver operating characteristic curves were created to identify cutoff points of strength for functional independence.

RESULTS

The best models for FIM total, FIM mobility, and SCIM total used 1RM as the best predictor (adjusted R²=.75, .67, and .65, respectively; P<.05). Relative strength (1RM/LBM) was the best predictor for SCIM mobility (adjusted R²=.62, P<.05). A FIM score of 69 has a 1RM cutoff point of 50.1kg, and a FIM score of 76 has cutoff points of .73 for 1RM/BM and .91 for 1RM/LBM. A SCIM score of 68 has cutoff points for 1RM, 1RM/BM, and 1RM/LBM of 50.1kg, .77, and .92, respectively.

CONCLUSIONS

Cutoff points of relative strength should be used as determinant variables for independence, health, or sports performance. This study may contribute to more adequate guidance of physical activity during a rehabilitation program and after discharge.

A randomized trial of high-dairy-protein, variable-carbohydrate diets and exercise on body composition in adults with obesity

OBJECTIVE

This study determined the effects of 16-week high-dairy-protein, variable-carbohydrate (CHO) diets and exercise training (EXT) on body composition in men and women with overweight/obesity.

METHODS

One hundred and eleven participants (age 47 ± 6 years, body mass 90.9 ± 11.7 kg, BMI 33 ± 4 kg/m(2) , values mean ± SD) were randomly stratified to diets with either: high dairy protein, moderate CHO (40% CHO: 30% protein: 30% fat; ∼4 dairy servings); high dairy protein, high CHO (55%: 30%: 15%; ∼4 dairy servings); or control (55%: 15%: 30%; ∼1 dairy serving). Energy restriction (500 kcal/day) was achieved through diet (∼250 kcal/day) and EXT (∼250 kcal/day). Body composition was measured using dual-energy X-ray absorptiometry before, midway, and upon completion of the intervention.

RESULTS

Eighty-nine (25 M/64 F) of 115 participants completed the 16-week intervention, losing 7.7 ± 3.2 kg fat mass (P < 0.001) and gaining 0.50 ± 1.75 kg lean mass (P < 0.01). There was no difference in the changes in body composition (fat mass or lean mass) between groups.

CONCLUSIONS

Compared to a healthy control diet, energy-restricted high-protein diets containing different proportions of fat and CHO confer no advantage to weight loss or change in body composition in the presence of an appropriate exercise stimulus.

Diet, exercise or diet with exercise: comparing the effectiveness of treatment options for weight-loss and changes in fitness for adults (18-65 years old) who are overfat, or obese; systematic review and meta-analysis

There are number of means of methods to alter body composition, and metabolic issues, available for the adult who is overfat. The following is a systematic review and meta-analysis focused on comparing changes from treatment program for adults who are overfat based on analysis of aggregated effect size (ES) of inducing changes. So as to determine the relative effectiveness of such protocols and intervention plans of choice. This tiered meta-analysis of 66-population based studies, and 162-studywise groups, a clear pattern of ES being established across and within treatments. First, hypocaloric balance is necessary for changing body composition, but the effectiveness for establishing imbalance does not equate with the effectiveness for body compositional changes, or any biomarkers associated with metabolic issues. With analysis showing that there is a necessity to include exercise in combination with diet effectively elicit changes in body composition and biomarkers of metabolic issues. More importantly, the combination, resistance training (RT) was more effective than endurance training (ET) or combination of RT and ET, particularly when progressive training volume of 2-to-3 sets for 6-to-10 reps at an intensity of ≥75% 1RM, utilizing whole body and free-weight exercises, at altering body compositional measures (ES of 0.47, 0.30, and 0.40 for loss of BM, FM, and retention of FFM respectively) and reducing total cholesterol (ES = 0.85), triglycerides (ES = 0.86) and low-density lipoproteins (ES = 0.60). Additionally RT was more effective at reducing fasting insulin levels (ES = 3.5) than ET or ET and RT. Even though generally lower ES than RT, the inclusion of ET was more effective when performed at high intensity (e.g. ≥70% VO2max or HRmax for 30-minutes 3-4x's/wk), or in an interval training style than when utilizing the relatively common prescribed method of low-to-moderate (e.g., 50-70% VO2max or HRmax for at least equal time) steady state method, ES of 0.35, 0.39, and 0.13 for BM, FM, and FFM respectively. Thus indicating that focus of treatment should be on producing a large metabolic stress (as induced by RT or high levels of ET) rather than an energetic imbalance for adults who are overfat.

Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings

Intermittent fasting (IF) regimens have gained considerable popularity in recent years, as some people find these diets easier to follow than traditional calorie restriction (CR) approaches. IF involves restricting energy intake on 1-3 d/wk, and eating freely on the nonrestriction days. Alternate day fasting (ADF) is a subclass of IF, which consists of a "fast day" (75% energy restriction) alternating with a "feed day" (ad libitum food consumption). Recent findings suggest that IF and ADF are equally as effective as CR for weight loss and cardioprotection. What remains unclear, however, is whether IF/ADF elicits comparable improvements in diabetes risk indicators, when compared with CR. Accordingly, the goal of this review was to compare the effects of IF and ADF with daily CR on body weight, fasting glucose, fasting insulin, and insulin sensitivity in overweight and obese adults. Results reveal superior decreases in body weight by CR vs IF/ADF regimens, yet comparable reductions in visceral fat mass, fasting insulin, and insulin resistance. None of the interventions produced clinically meaningful reductions in glucose concentrations. Taken together, these preliminary findings show promise for the use of IF and ADF as alternatives to CR for weight loss and type 2 diabetes risk reduction in overweight and obese populations, but more research is required before solid conclusions can be reached.

Metabolic adaptation to weight loss: implications for the athlete

Optimized body composition provides a competitive advantage in a variety of sports. Weight reduction is common among athletes aiming to improve their strength-to-mass ratio, locomotive efficiency, or aesthetic appearance. Energy restriction is accompanied by changes in circulating hormones, mitochondrial efficiency, and energy expenditure that serve to minimize the energy deficit, attenuate weight loss, and promote weight regain. The current article reviews the metabolic adaptations observed with weight reduction and provides recommendations for successful weight reduction and long term reduced-weight maintenance in athletes.

Effect of physical activity on weight loss, energy expenditure, and energy intake during diet induced weight loss

OBJECTIVE

Objective measurements of physical activity (PA), energy expenditure (EE) and energy intake can provide valuable information regarding appropriate strategies for successful sustained weight loss.

DESIGN AND METHODS

The total EE was examined by doubly labeled water, resting metabolic rate by indirect calorimetry, PA with activity monitors, and energy intake by the intake/balance technique in 116 severely obese undergoing intervention with diet alone (DO) or diet plus PA (D-PA).

RESULTS

Weight loss of 9.6 ± 6.8 kg resulted in decreased EE which was not minimized in the D-PA group. Comparing the highest and lowest quartiles of increase in PA revealed a lower decrease in TDEE (-122 ± 319 vs. -376 ± 305 kcal day⁻¹), elimination of the drop in AEE (83 ± 279 vs. -211 ± 284 kcal day⁻¹) and greater weight loss (13.0 ± 7.0 vs. 8.1 ± 6.3 kg). Increased PA was associated with greater adherence to energy restriction and maintenance of greater weight loss during months 7-12.

CONCLUSION

Noncompliance to prescribed PA in the DO and D-PA groups partially masked the effects of PA to increase weight loss and to minimize the reduced EE. Increased PA was also associated with improved adherence to prescribed caloric restriction. A strong recommendation needs to be made to improve interventions that promote PA within the context of behavioral weight loss interventions.

The Psychophysical Connection Between Exercise, Hunger, and Energy Intake

Exercise is vitally important in the prevention of weight gain or maintaining weight status, as well as weight loss. High-intensity exercise causes a short-term suppression of hunger of approximately 15 to 60 minutes. Although there is evidence for compensatory food consumption, it usually does not make up for the energy deficit created by exercise. The exception occurs when individuals consume or reward themselves with energy-dense foods or drink. Because people tend to eat the same volume of food each day, on days when they exercise, they will remain in an energy deficit. However, on sedentary days, a positive energy balance is likely if caloric restriction is not imposed, which could result in weight gain. Caloric restriction alone leads to loss of lean body mass, while the inclusion of exercise with an energy deficit helps conserve lean tissue. There are a myriad physiological factors such as the concentration of hormones (GLP-1, PYY3-36, leptin, and ghrelin) and metabolites (free fatty acids and glucose) that either stimulate or inhibit signals for hunger and/or energy intake, but the effect of exercise on these circulating factors is complex and not completely understood.

Effects of circuit-based exercise programs on the body composition of elderly obese women

Aim

The aim of this study was to investigate the impact of circuit-based exercise on the body composition in obese older women by focusing on physical exercise and body weight (BW) gain control in older people.

Methods

Seventy older women (>60 years old) voluntarily took part in the study. Participants were randomized into six different groups according to body mass index (BMI): appropriate weight (AW) control (AWC) and trained (AWT) groups, overweight (OW) control (OWC) and trained (OWT) groups, and obesity (O) control (OC) and trained (OT) groups. The exercise program consisted of 50 minutes of exercise three times per week for 12 weeks. The exercises were alternated between upper and lower body using rest between sets for 40 seconds with intensity controlled by heart rate (70% of work). The contraction time established was 5 seconds to eccentric and concentric muscular action phase. The following anthropometric parameters were evaluated: height (m), body weight (BW, kg), body fat (BF, %), fat mass (FM, kg), lean mass (LM, kg), and BMI (kg/m²).

Results

The values (mean ± standard deviation [SD]) of relative changes to BW (−8.0% ± 0.8%), BF (−21.4% ± 2.1%), LM (3.0% ± 0.3%), and FM (−31.2% ± 3.0%) to the OT group were higher (P < 0.05) than in the AWT (BW: −2.0% ± 1.1%; BF: −4.6% ± 1.8%; FM: −7.0% ± 2.8%; LM: 0.2% ± 1.1%) and OWT (BW: −4.5% ± 1.0%; BF: −11.0% ± 2.2%; FM: −16.1% ± 3.2%; LM: −0.2% ± 1.0%) groups; additionally, no differences were found for C groups. While reduction (P < 0.03) in BMI according to absolute values was observed for all trained groups (AWT: 22 ± 1 versus 21 ± 1; OWT: 27 ± 1 versus 25 ± 1, OT: 34 ± 1 versus 30 ± 1) after training, no differences were found for C groups.

Conclusion

In summary, circuit-based exercise is an effective method for promoting reduction in anthropometrics parameters in obese older women.

A randomized trial of protein supplementation compared with extra fast food on the effects of resistance training to increase metabolism

OBJECTIVE

To prospectively evaluate the effects of resistance training combined with increased energy intake or protein-supplementation on lean body-mass, resting metabolic-rate (RMR) and cardiovascular risk factors.

METHODS

Twenty-four healthy males (aged 19-32 years) performed resistance exercise for 12 weeks aiming for at least 1 hour training-sessions 3 times a week. The participants were randomized to consume extra protein (33 g whey protein/day) or a meal of fast-food/day (1350 kcal, 41 g protein). Body-composition was measured with Dual-Energy X-ray Absorptiometry (DEXA) and RMR by indirect calorimetry. Fasting blood samples were drawn before and after the 3-month training period and after 12 months.

RESULTS

The body weight increased from 75.1 ± 6.9 kg to 78.7 ± 7.2 kg (p < 0.0001), without differences between the groups. RMR increased from 1787 ± 143 kcal/24 h to 1954 ± 187 kcal/24 h (p < 0.0001, N = 24), which was more than expected from the increase in lean body-mass (increase from 59.7 ± 4.3 kg to 61.8 ± 4.1 kg p = 0.004). Fasting serum-insulin levels increased in the fast-food group compared with the extra-protein group (p = 0.03). ApoB increased from 0.691 ± 0.14 g/L to 0.768 ± 0.17 g/L, p = 0.004, in the fast-food group only. Long-term follow up after 12 months showed that RMR, body weight, total fat and lean body-masses did not differ from baseline (n = 19).

CONCLUSIONS

Resistance training for 12 weeks increased RMR and lean body-mass similarly when based on either an increased energy-intake or protein supplement. However, the increase in RMR was higher than expected from the increase in lean body-mass. Thus resistance training could potentially decrease the risk of obesity by induction of increased RMR.

A qualitative investigation of attitudes towards aerobic and resistance exercise amongst overweight and obese individuals

BACKGROUND

Most people are not meeting the minimal requirements for physical activity participation, particularly people who are overweight or obese. Numerous initiatives have been developed which aim to increase levels of physical activity in this group, yet little is known about their feelings towards different types of exercise. In particular, resistance exercise may offer unique benefits to people seeking to lose weight, yet no study to date has examined views of resistance exercise amongst the overweight and obese. This qualitative study examined the views and attitudes towards aerobic and resistance exercise amongst overweight and obese individuals engaged in a weight management clinic.

METHODS

30 overweight and obese patients comprised of 25 females and 5 males, with a mean age of 40.7 years (SD = 15.2) and mean BMI of 33.8 kg/m2 (SD = 7.9) were recruited from a dietetic clinic to take part in baseline focus groups and interviews to assess their views on physical activity. After selecting and participating in a 12 week aerobic- or resistance-exercise program, the participants took part in follow-up interviews. Thematic analysis was then performed on the transcribed focus group and interview data.

RESULTS

For the overweight and obese women in this study, weight loss was the primary motivation for physical activity participation. Subsequently, these women perceived a failure to lose weight as strongly affecting their motivation to continue or re-engage in physical activity. Only 3 participants selected the resistance exercise option. The view of resistance exercise as a masculine activity was a dominant theme amongst all participants. A lack of knowledge of how to perform certain exercises emerged as a barrier, but was seen by the participants as surmountable given appropriate instruction.

CONCLUSIONS

The females in this study cited weight loss as a primary motivation for physical activity participation. This view must be reconciled with the existing knowledge base of physical activity requirements for successful weight loss and maintenance. Participants in this study had little awareness or experience of resistance exercise, and many were fearful of the potential risks.

Effects of resistance or aerobic exercise training on total and regional body composition in sedentary overweight middle-aged adults

The purpose of this study was to examine the effects of 10 weeks of aerobic endurance training (AET), resistance exercise training (RET), or a control (CON) condition on absolute and relative fat mass (FM) or fat-free mass (FFM) in the total body (TB) and regions of interest (ROIs) of sedentary overweight middle-aged males and females. Following prescreening, 102 subjects underwent anthropometric measurements, dual-energy X-ray absorptiometry, and strength and aerobic exercise testing. Randomized subjects (male RET, n = 16; female RET, n = 19; male AET, n = 16; and female AET, n = 25) completed supervised and periodized exercise programs (AET, 30-50 min cycling at 70%-75% maximal heart rate; RET, 2-4 sets × 8-10 repetitions of 5-7 exercises at 70%-75% 1 repetition maximum) or a nonexercising control condition (male CON, n = 13 and female CON, n = 13). Changes in absolute and relative TB-FM and TB-FFM and ROI-FM and ROI-FFM were determined. At baseline, and although matched for age and body mass index, males had greater strength, aerobic fitness, body mass, absolute and relative TB-FFM and ROI-FFM, but reduced absolute and relative TB-FM and ROI-FM, compared with females (p < 0.05). After training, both female exercise groups showed equivalent or greater relative improvements in strength and aerobic fitness than did the male exercise groups (p < 0.05); however, the male exercise groups increased TB-FFM and reduced TB-FM more than did the female exercise groups (p < 0.05). Male AET altered absolute FM more than male RET altered absolute FFM, thus resulting in a greater enhancement of relative FFM. Despite equivalent or greater responses to RET or AET by female subjects, the corresponding respective increases in FFM or reductions in FM were lower than those in males, indicating that a biased dose-response relationship exists between sexes following 10 weeks of exercise training.

The impact of training modalities on the clinical benefits of exercise intervention in patients with cardiovascular disease risk or type 2 diabetes mellitus

Exercise training intervention represents an effective means to reduce adipose tissue mass, improve glycaemic control and increase whole-body oxygen uptake capacity (VO(2peak)) in obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM) and heart disease patients. In this manuscript, we review the impact of different exercise training modalities on clinical benefits of prolonged exercise intervention in these patient (sub)populations. By changing training modalities, significantly greater clinical benefits can be obtained. Greater training frequency and longer programme duration is associated with greater reduction in adipose tissue mass in obesity patients. A greater training frequency (up to 2 days/week) and a longer programme duration (up to 38 weeks) seems to be associated with greater improvements in VO(2peak) in heart disease patients. Longer programme duration and addition of resistance-type exercise further improve glycaemic control in T2DM patients. The first line of evidence seems to indicate that high-intensity interval exercise training has a greater impact on VO(2peak) in heart disease patients and insulin sensitivity in subjects with metabolic syndrome, but not on adipose tissue mass in obese subjects. However, it remains unclear whether addition of resistance-type exercise and continuous higher-intensity endurance-type exercise training are accompanied by greater improvements in VO(2peak) in heart disease patients. Furthermore, the impact of training session duration/volume on adipose tissue mass loss and glycaemic control in obesity and T2DM patients, respectively, is currently unknown. The impact of training frequency on glycaemic control remains to be investigated in T2DM patients.

Resistance training predicts 6-yr body composition change in postmenopausal women

PURPOSE

The aim of this study was to examine the association of exercise frequency (ExFreq) and volume (total weight lifted by military press and squats (SQ)) with change in body composition among postmenopausal women participating in a progressive resistance training study.

METHODS

Previously, sedentary women (n = 122, age = 56.3 +/- 4.3 yr) were followed for 6 yr. At 6 yr, there were women who had been randomly assigned to resistance training at baseline (n = 65) controls that were permitted to cross over to the exercise program at 1 yr (n = 32) and 25 true controls. Exercisers and crossovers directed to perform eight core exercises for two sets of eight repetitions at 70%-80% of one-repetition maximum, three times weekly, plus progressive weight bearing, stretching, and balance. Body weight and fat were measured at baseline and annually using anthropometry and dual-energy x-ray absorptiometry.

RESULTS

Average change in body weight and total body fat were 0.83 +/- 5.39 and 0.64 +/- 4.95 kg at 6 yr, respectively. In multiple linear regression, ExFreq, military press, and SQ were significantly inversely associated with change in body weight (standardized beta coefficient (SBC) = -0.22 to -0.28, P < 0.01), fat (SBC = -0.25 to -0.33, P < 0.01), and trunk fat (SBC = -0.20 to -0.31, P < 0.03) after adjusting for age, years on hormone therapy, change in lean soft tissue, baseline body composition, and baseline habitual exercise. The lowest tertile of SQ (equivalent to 2.5% attendance) demonstrated significant gain in weight, fat, and trunk fat over 6 yr (P < 0.004), whereas the highest tertile SQ (equivalent to 64% attendance) was able to maintain their weight, total, and regional fat.

CONCLUSIONS

We conclude that resistance training is a viable long-term method to prevent weight gain and deleterious changes in body composition in postmenopausal women.

Relative changes in resting energy expenditure during weight loss: a systematic review

A more comprehensive understanding of the effects of weight loss on the changes in resting energy expenditure (EE) is relevant. A MEDLINE search was performed to identify studies with information relevant to this systematic review. From this search, the mean rate of resting EE decrease relative to weight loss was calculated from 90 available publications. A decrease of resting EE relative to weight loss of -15.4 +/- 8.7 kcal kg(-1) was observed from 2977 [corrected] subjects. No sex differences were noted in the overall resting EE decrease relative to weight loss. However, a significant sex differences was seen with pharmacological interventions, which seemed to depress the resting EE relative to weight loss to a greater extent in men than in women (P < 0.05). A greater drop in resting EE relative to weight loss was observed for short interventions (more than 2 but less than 6 weeks) when compared with long interventions (<6 weeks) (-27.7 +/- 6.7 vs. -12.8 +/- 7.1 kcal kg(-1)) (P < 0.001). Men and women have a similar decrease in resting EE relative to weight loss except in the case of pharmacological interventions. Short interventions also produced greater resting EE losses relative to weight loss.

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.

Effects of mild calorie restriction and high-intensity interval walking in middle-aged and older overweight Japanese

We investigated whether a combination of mild calorie restriction (MCR) and high-intensity interval walking (HIW) improved physical fitness more than HIW alone in middle-aged and older overweight Japanese (40-69years old, BMI23.6kg/m(2)). Forty-seven women and 16 men were divided into MCR+HIW and HIW groups. All subjects performed HIW: 5 sets of 3-min low-intensity walking (40% peak aerobic capacity for walking, VO(2peak)) and 3-min high-intensity walking (70% VO(2peak)) per day, 4days per week, for 16weeks while energy expenditure was monitored with a tri-axial accelerometer. The MCR+HIW group consumed meal replacement formula (240kcal): a mixture of low-carbohydrates and -fat and high-protein, for either lunch or dinner everyday and therefore, had approximately 87% of the energy intake of the HIW group during the intervention period. Although the HIW group showed improvements in BMI, blood pressure, and several blood chemicals, the MCR+HIW group had greater improvement. Moreover, the medical expenditure for the 6months including the intervention period was 59% lower in the MCR+HIW group than in the HIW group. Our strategy of a short-term combination of MCR and HIW may thus prevent lifestyle-associated diseases and improve health in middle-aged and older overweight Japanese.

Effects of caloric restriction and overnight fasting on cycling endurance performance

In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

Effect of dietary adherence with or without exercise on weight loss: a mechanistic approach to a global problem

CONTEXT

Weight loss using low-calorie diets produces variable results, presumably due to a wide range of energy deficits and low-dietary adherence.

OBJECTIVE

Our objective was to quantify the relationship between dietary adherence, weight loss, and severity of caloric restriction.

DESIGN AND SETTING

Participants were randomized to diet only, diet-endurance training, or diet-resistance training until body mass index (BMI) was less than 25 kg/m(2).

PARTICIPANTS

Healthy overweight (BMI 27-30) premenopausal women (n = 141) were included in the study.

INTERVENTIONS

An 800-kcal/d(-1) diet was provided, and the exercise groups were engaged in three sessions per week.

MAIN OUTCOMES

Dietary adherence, calculated from total energy expenditure determined by doubly labeled water measurements and dual-energy x-ray absorptiometry body composition changes, and degree of caloric restriction were determined.

RESULTS

All groups had similar weight loss (approximately 12.1 +/- 2.5 kg) and length of time to reach target BMI (approximately 158 +/- 70 d). Caloric restriction averaged 59 +/- 9%, and adherence to diet was 73 +/- 34%. Adherence to diet was inversely associated to days to reach target BMI (r = -0.687; P < 0.01) and caloric restriction (r = -0.349; P < 0.01). Association between adherence to diet and percent weight lost as fat was positive for the diet-endurance training (r = 0.364; P < 0.05) but negatively correlated for the diet-only group (r = -0.387; P < 0.05).

CONCLUSIONS

Dietary adherence is strongly associated with rates of weight loss and adversely affected by the severity of caloric restriction. Weight loss programs should consider moderate caloric restriction relative to estimates of energy requirements, rather than generic low-calorie diets.

Increased strength and decreased flexibility are related to reduced oxygen cost of walking

Purpose was to determine effects resistance training/weight loss induced changes in muscular strength and flexibility have on net walking oxygen uptake (netVO(2)). Sixty-seven premenopausal women lost 12 kg. Before weight loss subjects were assigned to diet (WL) or diet/3 days per week resistance training (WLRT). Resting energy expenditure, oxygen uptake while walking at 4.84 km h(-1) on the flat and up 2.5% grade, isometric knee extension strength, and flexibility of the knee extensors and plantar flexors were measured. Strength increased in WLRT (+36 N) but not in WL (-24 N). NetVO(2) decreased significantly while flat walking (7.3%) and 2.5% grade walking (5.7%) in WLRT, but not in WL. Delta strength was negatively while delta knee extensor and plantar flexor flexibility were positively related to delta netVO(2). Decreases in walking and grade netVO(2) were independently and positively related to increased knee extension strength and decreased knee extensor and plantar flexor flexibility.

The effect of a hypocaloric diet with and without exercise training on body composition, cardiometabolic risk profile, and reproductive function in overweight and obese women with polycystic ovary syndrome

CONTEXT

In overweight women with polycystic ovary syndrome (PCOS), the benefits of the addition of exercise to an energy-restricted diet in further improving cardiometabolic risk factors and reproductive function has not been extensively studied.

OBJECTIVE

The objective was to evaluate the effects of aerobic and aerobic-resistance exercise when combined with an energy-restricted high protein diet (5000-6000 kJ/d) on metabolic risk factors and reproductive function in women with PCOS.

DESIGN AND SETTING

A 20-wk outpatient, randomized, parallel study was conducted in a metropolitan research clinic.

PATIENTS AND INTERVENTION

Ninety-four overweight and obese women with PCOS (age 29.3 +/- 0.7 yr; body mass index 36.1 +/- 0.5 kg/m2) were randomized to diet only (DO; n = 30), diet and aerobic exercise (DA; n = 31), or diet and combined aerobic-resistance exercise (DC; n = 33).

MAIN OUTCOME MEASURES

Weight, body composition, cardiometabolic risk factors, hormonal status, menstrual cyclicity, and ovulatory function were assessed.

RESULTS

All interventions reduced weight (DO 8.9 +/- 1.6%, DA 10.6 +/- 1.7%, and DC 8.7 +/- 1.7%; P < 0.001) with no difference between treatments (P = 0.7, time x treatment). Fat mass decreased more (3 kg) and fat-free mass decreased less (2 kg) in DA and DC compared with DO (P < or = 0.03). Reductions in blood pressure (5.6/2.7 mm Hg), triglycerides (0.4 mmol/liter), total cholesterol (0.5 mmol/liter), low-density lipoprotein cholesterol (0.1 mmol/liter), glucose (0.2 mmol/liter), fasting insulin (4.3 mIU/liter), testosterone (0.4 nmol/liter), and free androgen index (2.8) (P < 0.001) and improvements in SHBG (7.0 nmol/liter) and reproductive function occurred in all groups, with no difference between treatments.

CONCLUSION

In overweight and obese women with PCOS, the addition of aerobic or combined aerobic-resistance exercise to an energy-restricted diet improved body composition but had no additional effect on improvements in cardiometabolic, hormonal, and reproductive outcomes relative to diet alone.

A comparison of aerobic exercise and resistance training in patients with and without chronic kidney disease

The morbidity and mortality associated with chronic kidney disease (CKD) are primarily caused by atherosclerosis and cardiovascular disease, which may be in part caused by inflammation and oxidative stress. Aerobic exercise and resistance training have been proposed as measures to combat obesity, inflammation, endothelial dysfunction, oxidative stress, insulin resistance, and progression of CKD. In non-CKD patients, aerobic exercise reduces inflammation, increases insulin sensitivity, decreases microalbuminuria, facilitates weight loss, decreases leptins, and protects against oxidative injury. In nondialysis CKD, aerobic exercise decreases microalbuminuria, protects from oxidative stress, and may increase the glomerular filtration rate (GFR). Aerobic exercise in hemodialysis patients has been reported to enhance insulin sensitivity, improve lipid profile, increase hemoglobin, increase strength, decrease blood pressure, and improve quality of life. Resistance training, in the general population, decreases C-reactive protein, increases insulin sensitivity, decreases body fat content, increases insulin-like growth factor-1 (IGF-1), and decreases microalbuminuria. In the nondialysis CKD population, resistance training has been reported to reduce inflammation, increase serum albumin, maintain body weight, increase muscle strength, increase IGF-1, and increase GFR. Resistance training in hemodialysis increases muscle strength, increases physical functionality, and improves IGF-1 status. Combined aerobic exercise and resistance training during dialysis improves muscle strength, work output, cardiac fitness, and possibly dialysis adequacy. There is a need for more investigation on the role of exercise in CKD. If the benefits of aerobic exercise and strength training in non-CKD populations can be shown to apply to CKD patients as well, renal rehabilitation will begin to play an important role in the approach to the treatment, prevention, and slowed progression of CKD.

The effects of dietary energy restriction on overloaded skeletal muscle in rats

We evaluated the effects of three levels of energy intake, 73 % (CON73), 81 % (CON81) and 100 % (CON100) of the ad libitum intake of the control diet, on skeletal muscle growth induced by functional overload in male rats. Unlike most previous studies which have employed chronic or acute food restriction where all nutrients are reduced in the diet, the present study tested the effects of energy deprivation as a single factor without inducing other nutritional deficiencies. Muscular growth of plantaris and soleus muscles was induced by removal of synergist gastrocnemius muscles in one hindlimb; muscles in the other leg were used as sham-operated intra-animal controls. After 30 d, rats on the energy-restricted CON73 and CON81 diets gained less weight and had smaller livers, kidneys, hearts and fat pads (epididymal, retroperitoneal and omental) than CON100 rats (P<0·05). They also had smaller sham-operated plantaris muscles (CON73 -13 %, CON81 -9 %) containing less total protein (CON73 -14 %; CON81 -10 %) than CON100 rats (P<0·05). However, the same measurements in overloaded plantaris muscles were similar among groups. Soleus muscle mass and protein contents were not significantly affected by energy restriction in our study. Percentage distributions of myosin heavy-chain isoforms (types I, IIa, IIx and IIb) were similar among rats in CON100, CON81 and CON73 groups for both plantaris and soleus muscles. We conclude that the growth reduction of plantaris muscle induced by energy restriction at 73 % and 81 % for 30 d was prevented by functional overload in male rats.

The effects of aerobic and resistance exercises in obese women

OBJECTIVE

To compare the effects of aerobic and resistance exercise on weight, muscle strength, cardiovascular fitness, blood pressure and mood in obese women who were not on an energy-restricted diet.

DESIGN

Randomized, prospective, controlled trial.

SETTING

Department of Physical Medicine and Rehabilitation, University Hospital.

SUBJECTS

Sixty obese women were assigned to one of three groups: aerobic exercise (n = 20), resistance exercise (n = 20) and control group (n = 20).

INTERVENTIONS

The aerobic exercise group performed both walking and leg cycle exercise with increasing duration and frequency. The resistance exercise group performed progressive weight-resistance exercises for the upper and lower body.

MAIN OUTCOME MEASURES

Before and after a 12-week period, all subjects were evaluated by anthropometric measurement, rating of mood, cardiorespiratory capacity and maximum strength of trained muscles.

RESULTS

After a 12-week training period, subjects in the resistance group showed significant improvement in one-repetition maximum test of hip abductors (7.95+/-3.58 kg), quadriceps (14+/-7.18 kg), biceps (3.37+/- 2.84 kg) and pectorals (8.75+/-5.09 kg) compared with those in the control group (P < 0.001). VO2 max increased (0.51+/-0.40) and Beck Depression Scale scores decreased (-5.40+/-4.27) in the aerobic exercise group compared with the control group, significantly (P < 0.001). Only in hip abductor muscle strength was there a significant increase in the resistance exercise group compared with the aerobic exercise group (P < 0.05).

CONCLUSION

Both aerobic exercise and resistance exercise resulted in improved performance and exercise capacity in obese women. While aerobic exercise appeared to be beneficial with regard to improving depressive symptoms and maximum oxygen consumption, resistance exercise was beneficial in increasing muscle strength.