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Background: The prevalence of excessive gestation weight gain, extended postpartum weight retention and pregravid obese women is increasing and is associated with numerous adverse health outcomes.Objective: To review the evidence from studies employing exercise-only interventions for weight management among pregnant and postpartum women.Search Strategy: Ten databases were searched for randomised controlled trials conducted during pregnancy or within the 12 months following childbirth and published between 1990 and 2013.Selection Criteria: There were no restrictions to the type, frequency, duration or intensity of exercise intervention. Interventions not specifically designed to target weight were excluded. The outcomes were a change in body weight (kg) or body mass index (BMI; kg/m(2)).Data Collection and Analysis: All data were continuous and were reported as weighted mean differences (WMD), with 95% CIs. Data were analysed with a fixed-effect model and heterogeneity was determined using the I(2) statistic.Results: Five studies were included in this review. Exercise significantly reduced gestational weight gain (WMD=-2.22 kg, CI -3.14 to -1.3, p≤0.00001) and had no significant effect on postpartum weight loss (WMD=-1.74 kg, CI -3.59 to 0.10, p=0.06) or BMI during pregnancy (WMD=-2.8 kg/m(2), CI -5.60 to 0.00, p=0.05) or postpartum (WMD=-0.54 kg/m(2), CI -1.17 to 0.08, p=0.09).Conclusions: There is currently limited evidence to suggest that exercise can be used to limit maternal gestational weight gain. [ABSTRACT FROM AUTHOR]

Objectives: To study the effects of eight weeks of supervised, Iow intensity resistance training (80% of 10 repetition maximum (10RM)) and eight weeks of detraining on muscle strength and blood lipid profiles in healthy, sedentary postmenopausal women. Subjects: Fifteen postmenopausal women, aged 49-62 years, took part in the study. Subjects were assigned to either a control (n = 7) or training (n = 8) group. The training regimen consisted of three sets of eight repetitions of leg press, bench press, knee extension, knee flexion, and lat pull-down, three days a week at 80% of 10RM. Dynamic leg strength, 10RM, and blood lipid profiles (total cholesterol (TC), Iow and high density lipoprotein cholesterol (LDL-C, HDL-C), triglycerides, and very Iow density lipoprotein cholesterol (VLDL-C)) were measured at baseline, after eight weeks of training, and after a further eight weeks of detraining. Results: Eight weeks of resistance training produced significant increases in knee extension (F[sub 1,13] = 12.60; p<0.01), bench press (F[sub 1,13] = 13.79; p<0.01), leg press (F[sub 1,13] = 15.65; p<0.01), and lat pulldown (F[sub 1,13] = 16.60; p<0.005) 10RM strength tests. Although 10RM strength decreased after eight weeks of detraining, the results remained significantly elevated from baseline measures. Eight weeks of training did not result in any significant alterations in blood lipid profiles, body composition, or dynamic isokinetic leg strength. There were no significant differences in any of the variables investigated over the 16 week period in the control group. Conclusions: These data suggest that a short, Iow intensity resistance training programme produces substantial improvements in muscle strength. Training of this intensity and duration was not sufficient to produce significant alterations in blood lipid concentrations. [ABSTRACT FROM AUTHOR]

Competing Interests: Competing interests: BS has previously received financial support from Natural Alternatives International (NAI), a company that produces β-alanine, to undertake a study unrelated to this review. NAI have also provided β-alanine supplements free of charge for further experimental investigations and supported open access page charges for several of the author’s manuscripts. NAI have not had any input (financial, intellectual or otherwise) into this review.

Objective: To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance., Design: This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data., Data Sources: 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms ('β-alanine' and 'Beta-alanine' combined with 'supplementation', 'exercise', 'training', 'athlete', 'performance' and 'carnosine')., Eligibility Criteria for Selecting Studies: Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses., Results: 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI -0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64))., Summary/conclusions: β-alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-alanine supplementation based on their chosen exercise modality., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)