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ObjectiveThe objective of this brief literature review was to identify and summarize the research on exercise’s effects on breastmilk composition and supply and report the implications of these findings.MethodAn online database search was conducted; sixteen articles met the inclusion criteria and were included within the review.ResultsBreastfeeding mothers were observed to have higher total milk volume, IgA, and lactic acid concentrations after maximal exercising. Exercising does not seem to affect lipid or major micronutrient content in breastmilk. These changes in supply and composition do not seem to affect lactation performance or infant acceptance.ConclusionDue to the limited evidence available, further research needs to be conducted to draw stronger conclusions on how exercise affects breastmilk composition and supply. Research is also warranted to clarify exercise/physical activity guidelines for women who are breastfeeding.

Background: Exercise has been shown to improve heart rate variability (HRV) at rest in healthy subjects. HRV response during and immediately after acute exercise in obese individuals following aerobic exercise training has not been evaluated. The purpose of this study was to examine the effect of 12 weeks of moderate intensity aerobic exercise training on HRV during acute exercise and active postexercise recovery in obese individuals. Methods: Eleven obese individuals (5 men, 6 women; body mass index = 39.2 ± 6.3 kg·m−2] underwent 12 weeks of exercise training at 60% of predicted VO2max, determined via a submaximal treadmill test. Body composition was assessed with dual-energy x-ray absorptiometry. HRV was measured during the final minute in each exercise stage and in recovery and analyzed with Kubios HRV software. Results: Predicted VO2max (baseline: 28.2 ± 3.5 mL·kg−1·min−1 and posttraining: 27.4 mL·kg−1·min−1, P > 0.05) was unchanged and body fat % decreased (46.2% ± 2.2 vs 45.5% ± 7.2, respectively). Initial stage heart rate and postexercise recovery heart rate was lower after training. The high frequency component was greater during the initial exercise stage after training. The low frequency component and the standard deviation of instantaneous beat-to-beat variability were greater during the final exercise stage after training. During cooldown, the root-mean-square of differences between adjacent RR intervals and high frequency normalized units were greater after training. Conclusion: HRV markers were improved during acute exercise stage and active recovery in obese individuals following 12 weeks of moderate intensity exercise training. These results suggest improvements in autonomic function can be seen with reductions in adiposity, independent of cardiorespiratory fitness changes in obese adults.

Obstructive sleep apnea (OSA) is a prevalent form of sleep disordered breathing that increases ones risk for numerous chronic health conditions such as cardiovascular disease and diabetes mellitus. A limited number of studies have suggested that exercise training, mostly focusing on light-to-moderate intensities, may positively impact OSA severity and other health outcomes. This case study describes a moderately active man who was diagnosed as pre-diabetic through his physician and found to likely have moderate severity OSA through at-home screening device. He underwent eight of aerobic training at vigorous intensity.

This study investigated the effects of coffee ingestion with supplemental caffeine (CAF) on serum testosterone (T) responses to exercise in recreationally strength-trained males.Subjects ingested 6 mg/kg body weight of caffeine via 12 ounces of coffee (CAF) supplemented with anhydrous caffeine or decaffeinated (DEC) coffee prior to exercise in a randomized, within-subject, crossover design. The exercise session consisted of 21 minutes of high-intensity interval cycling (alternating intensities at power outputs associated with 2.0 mmol/L lactate for two minutes and 4.0 mmol/L lactate for one minute) followed by resistance exercise (seven exercises, three sets of ten repetitions, 65% 1RM, one-minute rest periods). Subjects also completed repetitions to fatigue tests and soreness scales to determine muscle recovery 24 hours following the exercise.T was elevated immediately and 30-minutes post-exercise by 20.5% and 14.3% respectively (P0.05). There was no main effect for treatment and no exercise x treatment interaction. There were no differences in repetitions to fatigue or soreness between treatments (P0.05). No relationships were observed between T and any proxy of recovery.While past literature suggests caffeine may enhance T post-exercise, data from the current study suggest that augmented T response is not evident following anhydrous caffeine added to coffee. The duration of T elevation indicates that this protocol is beneficial to creating long-lasting increases in serum testosterone.

The purpose of this study is to explore a possible relationship between breakfast consumption and basketball shooting performance. Eighteen male subjects (height=191.5±10.1 cm, mass=93.8±12.1 kg, age=27.5±10.6 years) with considerable amount of basketball playing experience were divided into two groups, with (BF) and without (No-BF) four-day breakfast consumption in a three-week cross-over study design. Subjects completed free throw, 2-point, and 3-point shooting drills on the fourth day of each week. Food intake records were collected during each treatment phase. Paired sample t-tests were used to examine the difference in basketball shooting performance (free throw, 2-point, and 3-point drills) and dietary intake patterns (calories, carbohydrates, proteins, and fats) between BF and No-BF testing weeks. Cohen’s D effect sizes were calculated to determine the magnitude of the breakfast consumption as an experimental factor. The average amount of calories, carbohydrates, proteins, and fats that the subjects consumed during the breakfast omission week was significantly lower when compared to the breakfast consumption week. Even though the overall basketball shooting performance was improved during the breakfast consumption week, only the average free throw shooting accuracy revealed statistically significant results. However, the effect sizes for almost all the dependent variables exhibited small to moderate magnitudes. Considering that basketball players are always looking for ways to improve their shooting performance, a well-balanced diet with habitual breakfast consumption may be a beneficial method for individual and team performance enhancement, which can ultimately lead to increased chances of a successful game outcome.

The present study was designed to evaluate the 16 weeks diabetes prevention program (DPP) combined with instructed run sprint interval training (INT) or moderate-intensity continuous training (MICT) on glycemic control, body composition, fitness, exercise adherence, and perceived exercise enjoyment in sedentary, adults with prediabetes. Participants completed three weekly supervised sessions of INT (4–10 bouts of 30 s maximal sprints followed by a 4 min active recovery) or MICT (30–60 min at 45–55% HRR) exercise coupled with the DPP for 16 weeks. At baseline, 8 and 16 weeks, participants completed fitness and clinical assessments as well as questionnaires to assess group and time differences. Twenty-nine study participants (INT n = 17, MICT n = 12) were randomized, however, significantly (p = 0.024) more participants withdrew from the INT (n = 11) than MICT (n = 4) treatment. There was no significant difference between groups in perceived exercise enjoyment, but, the MICT group significantly improved their perceived exercise enjoyment (10.8 ± 14.2; p = 0.021) from baseline to 16 weeks. Both INT and MICT groups decreased their body weight (2.0 ± 0.8 vs. − 5.5 ± 1.4 kg; p

The effects of protein supplementation on cycling performance, skeletal muscle function, and heart rate responses to exercise were examined following intensified (ICT) and reduced-volume training (RVT). Seven cyclists performed consecutive periods of normal training (NT), ICT (10 days; average training duration 220% of NT), and RVT (10 days; training duration 66% of NT). In a crossover design, subjects consumed supplemental carbohydrate (CHO) or an equal amount of carbohydrate with added protein (CP) during and following each exercise session (CP = +0.94 g/kg/day protein during ICT; +0.39 g/kg/day during RVT). A 30-kilometer time trial performance (following 120 min at 50% Wmax) was modestly impaired following ICT (+2.4 ± 6.4% versus NT) and returned to baseline levels following RVT (−0.7 ± 4.5% versus NT), with similar responses between CHO and CP. Skeletal muscle torque at 120 deg/s benefited from CP, compared to CHO, following ICT. However, this effect was no longer present at RVT. Following ICT, muscle fiber cross-sectional area was increased with CP, while there were no clear changes with CHO. Reductions in constant-load heart rates (at 50% Wmax) following RVT were likely greater with CP than CHO (−9 ± 9 bpm). Overall it appears that CP supplementation impacted skeletal muscle and heart rate responses during a period of heavy training and recovery, but this did not result in meaningful changes in time trial performance.

Sports that emphasize low body weight for optimal performance, such as ballet, are associated with an increased prevalence of the female athlete triad (FT). Previous research in this area that involves dancers has been limited; the majority of studies have been performed on adolescents training in classical ballet, and not professional adult dancers. The purpose of this study is to compare the physical and behavioral characteristics of female elite ballet dancers to sedentary, recreation-ally active non-dancing controls, with regard to characteristics of the FT and energetic efficiency. Women aged 18 to 35 years were recruited as participants. The dancers (N =15) and non-dancing controls (N =15) were pair-matched via age (dancers: 24.3 ±1.3 years; controls: 23.7 ± 0.9 years), body mass index (dancers: 18.9 ± 0.2; controls: 19.4 ± 0.2 kg/m2), and fat-free mass (dancers: 44.3 ± 0.8; controls: 44.1 ± 0.9 kg). Assessments included habitual dietary intake using 4-day food records, self-reported physical activity, psychometric measures of eating behaviors, health and menstrual history, body composition and bone density (dual energy x-ray absorptiometry), and resting metabolic rate (RMR) assessed by indirect calorimetry. Characteristics of the FT, specifically menstrual irregularities (6 of 15 dancers reported irregular or no menses; 1 of 15 controls reported irregular menses) and low energy availability, were more prevalent in dancers than in pair-matched controls. Despite having a similar fat-free mass (FFM), dancers had a significantly lower absolute RMR (dancers: 1367 ± 27; controls: 1454 ± 34 kcal/d; p ≤ 0.05) and significantly lower RMR relative to FFM (dancers: 30.9 ± 0.6; controls: 33.1 ± 0.8 kcal/kg fat-free mass/d; p ≤ 0.05). Energy intake between dancers (1577 ± 89 kcal/d) and pair-matched controls (2075 ± 163 kcal/d) also differed significantly (p ≤ 0.01). Six of the 15 dancers met the criteria for the FT (including low bone mineral density, menstrual irregularities, and eating pathology accompanied by low energy availability) and, therefore, represent a population of individuals afflicted with this disorder. These findings provide insight as to the metabolic impact of chronic energy restriction, and suggest that alterations in RMR (i.e., energetic efficiency) may be an indicator of low energy availability. Future larger-scale studies are warranted to address this possibility. Interventions aimed at increasing energy availability in elite female ballet dancers may be needed to promote optimal health status.

Individuals successful at weight loss maintenance (WTLM) utilize similar behaviors but in varying amounts and combinations. Research identifying characteristics which predict WTLM success could be used to develop effective WTLM treatment programs. The purpose of this retrospective analysis was to determine behavioral (e.g., self monitoring of dietary intake) and biological factors (e.g., sex) which may influence WTLM success. Methods: In a previously conducted 12-month WTLM study, weight-reduced middle-aged and older men and women (n = 39) were assigned behavioral goals and asked to daily self-monitor body weight, fruit and vegetable intake, water consumption, and physical activity. This investigation utilized a crisp set qualitative comparative analysis (QCA) to characterize individuals’ weight changes and behaviors. Sex difference in clinically significant weight loss (WL) (≥5% WL) at 12 months was investigated, and growth curve models estimated interaction effects between sex and WTLM predictors. Results: QCA findings suggest patterns of weight change during the initial three months of WTLM treatment may dictate 12-month weight outcomes. No sex difference was found in clinically significant WL or in the interaction of sex and behaviors on weight change. Conclusions: WTLM treatments should provide more intensive support during transition from WL to WTLM, particularly during the first three months.

Maintenance of weight loss remains a challenge for most individuals. Thus, practical and effective weight-loss maintenance (WTLM) strategies are needed. A two-group 12-month WTLM intervention trial was conducted from June 2007 to February 2010 to determine the feasibility and effectiveness of a WTLM intervention for older adults using daily self-monitoring of body weight, step count, fruit/vegetable (F/V) intake, and water consumption. Forty weight-reduced individuals (mean weight lost=6.7±0.6 kg; body mass index [calculated as kg/m²] 29.2±1.1), age 63±1 years, who had previously participated in a 12-week randomized controlled weight-loss intervention trial, were instructed to record daily body weight, step count, and F/V intake (WEV [defined as weight, exercise, and F/V]). Experimental group (WEV+) participants were also instructed to consume 16 fl oz of water before each main meal (ie, three times daily), and to record daily water intake. Outcome measures included weight change, diet/physical activity behaviors, theoretical constructs related to health behaviors, and other clinical measures. Statistical analyses included growth curve analyses and repeated measures analysis of variance. Over 12 months, there was a linear decrease in weight (β=-0.32, P0.001) and a quadratic trend (β=0.02, P0.01) over time, but no group difference (β=-0.23, P=0.08). Analysis of the 365 days of self-reported body weight for each participant determined that weight loss was greater over the study period in the WEV+ group than in the WEV group, corresponding to weight changes of -0.67 kg and 1.00 kg, respectively, and an 87% greater weight loss (β=-0.01, P0.01). Overall compliance to daily tracking was 76%±5%. Daily self-monitoring of weight, physical activity, and F/V consumption is a feasible and effective approach for maintaining weight loss for 12 months, and daily self-monitoring of increased water consumption may provide additional WTLM benefits.

Sports that emphasize low body weight for optimal performance, such as ballet, are associated with an increased prevalence of the female athlete triad (FT). Previous research in this area that involves dancers has been limited; the majority of studies have been performed on adolescents training in classical ballet, and not professional adult dancers. The purpose of this study is to compare the physical and behavioral characteristics of female elite ballet dancers to sedentary, recreationally active non-dancing controls, with regard to characteristics of the FT and energetic efficiency. Women aged 18 to 35 years were recruited as participants. The dancers (N = 15) and non-dancing controls (N = 15) were pair-matched via age (dancers: 24.3 ± 1.3 years; controls: 23.7 ± 0.9 years), body mass index (dancers: 18.9 ± 0.2; controls: 19.4 ± 0.2 kg/m 2 ), and fat-free mass (dancers: 44.3 ± 0.8; controls: 44.1 ± 0.9 kg). Assessments included habitual dietary intake using 4-day food records, self-reported physical activity, psychometric measures of eating behaviors, health and menstrual history, body composition and bone density (dual energy x-ray absorptiometry), and resting metabolic rate (RMR) assessed by indirect calorimetry. Characteristics of the FT, specifically menstrual irregularities (6 of 15 dancers reported irregular or no menses; 1 of 15 controls reported irregular menses) and low energy availability, were more prevalent in dancers than in pair-matched controls. Despite having a similar fat-free mass (FFM), dancers had a significantly lower absolute RMR (dancers: 1367 ± 27; controls: 1454 ± 34 kcal/d; p ≤ 0.05) and significantly lower RMR relative to FFM (dancers: 30.9 ± 0.6; controls: 33.1 ± 0.8 kcal/kg fat-free mass/d; p ≤ 0.05). Energy intake between dancers (1577 ± 89 kcal/d) and pair-matched controls (2075 ± 163 kcal/d) also differed significantly (p ≤ 0.01). Six of the 15 dancers met the criteria for the FT (including low bone mineral density, menstrual irregularities, and eating pathology accompanied by low energy availability) and, therefore, represent a population of individuals afflicted with this disorder. These findings provide insight as to the metabolic impact of chronic energy restriction, and suggest that alterations in RMR (i.e., energetic efficiency) may be an indicator of low energy availability. Future larger-scale studies are warranted to address this possibility. Interventions aimed at increasing energy availability in elite female ballet dancers may be needed to promote optimal health status.

The number of US adults classified as overweight or obese has dramatically increased in the past 25 years, resulting in a significant body of research addressing weight loss and weight loss maintenance. However, little is known about the potential of weight loss maintenance interventions to be translated into actual practice settings. Thus, the purpose of this article is to determine the translation potential of published weight loss maintenance intervention studies by determining the extent to which they report information across the reach, efficacy/effectiveness, adoption, implementation, and maintenance (RE-AIM) framework. A secondary purpose is to provide recommendations for research based on these findings. To identify relevant research articles, a literature search was conducted using four databases; 19 weight loss maintenance intervention studies were identified for inclusion. Each article was evaluated using the RE-AIM Coding Sheet for Publications to determine the extent to which dimensions related to internal and external validity were reported. Approximately half of the articles provided information addressing three RE-AIM dimensions, yet only a quarter provided information addressing adoption and maintenance. Significant gaps were identified in understanding external validity, and metrics that could facilitate the translation of these interventions from research to practice are presented. Based upon this review, it is unknown how effective weight loss maintenance interventions could be in real-world situations, such as clinical or community practice settings. Future studies should be planned to address how weight loss maintenance intervention programs will be adopted and maintained, with special attention to costs for participants and for program implementation.