Effects of exercise on bone marrow adipose tissue in children with overweight/obesity: role of liver fat.

CONTEXT: Exercise reduces adiposity, but its influence on bone marrow fat fraction (BMFF) is unknown; nor is it known whether a reduction in liver fat content mediates this reduction. OBJECTIVES: (i) To determine whether incorporating exercise into a lifestyle program reduces the lumbar spine (LS)-BMFF, and (ii), to investigate whether changes in liver fat mediate any such effect. DESIGN: Ancillary analysis of a two-arm, parallel, non-randomized clinical trial. SETTING: Primary care centres in Vitoria-Gasteiz (Spain). PARTICIPANTS: A total of 116 children with overweight/obesity were assigned to a 22-week family-based lifestyle program (control group [n=57]) or the same program plus an exercise intervention (exercise group [n=59]. INTERVENTIONS: The compared interventions consisted of a family-based lifestyle program (two 90-minute sessions/month) and the same program plus supervised exercise (three 90-minute sessions/week). MAIN OUTCOMES AND MEASURES: The primary outcome examined was the change in LS-BMFF between baseline and 22 weeks, as estimated by MRI. The effect of changes in hepatic fat on LS-BMFF were also recorded. RESULTS: Mean weight loss difference between groups was 1.4±0.5 kg favour of the exercise group. Only the children in the exercise group experienced a reduction in LS-BMFF (effect size [Cohen d] -0.42, CI: -0.86, -0.01). Importantly, 40.9% of the reductions in LS-BMFF were mediated by changes in percentage hepatic fat (indirect effect: ß=-0.104, 95%CI=-0.213, -0.019). The impact of changes in hepatic fat on LS-BMFF was independent of weight loss. CONCLUSIONS AND RELEVANCE: The addition of exercise to a family-based lifestyle program designed to reduce cardiometabolic risk improves bone health by reducing LS-BMFF in children with overweight or obesity. This beneficial effect on bone marrow appears to be mediated by reductions in liver fat.

Efficacy of different 8 h time-restricted eating schedules on visceral adipose tissue and cardiometabolic health: A study protocol.

BACKGROUND AND AIMS: To investigate the efficacy and feasibility of three different 8 h time-restricted eating (TRE) schedules (i.e., early, late, and self-selected) compared to each other and to a usual-care (UC) intervention on visceral adipose tissue (VAT) and cardiometabolic health in men and women. METHODS AND RESULTS: Anticipated 208 adults (50% women) aged 30-60 years, with overweight/obesity (25 ≤ BMI<40 kg/m2) and with mild metabolic impairments will be recruited for this parallel-group, multicenter randomized controlled trial. Participants will be randomly allocated (1:1:1:1) to one of four groups for 12 weeks: UC, early TRE, late TRE or self-selected TRE. The UC group will maintain their habitual eating window and receive, as well as the TRE groups, healthy lifestyle education for weight management. The early TRE group will start eating not later than 10:00, and the late TRE group not before 13:00. The self-selected TRE group will select an 8 h eating window before the intervention and maintain it over the intervention. The primary outcome is changes in VAT, whereas secondary outcomes include body composition and cardiometabolic risk factors. CONCLUSION: This study will determine whether the timing of the eating window during TRE impacts its efficacy on VAT, body composition and cardiometabolic risk factors and provide insights about its feasibility.

Does the Combined Effect of Resistance Training with EPO and Iron Sulfate Improve Iron Metabolism in Older Individuals with End-Stage Renal Disease?

We sought to investigate the effects of resistance training (RT) combined with erythropoietin (EPO) and iron sulfate on the hemoglobin, hepcidin, ferritin, iron status, and inflammatory profile in older individuals with end-stage renal disease (ESRD). ESRD patients (n: 157; age: 66.8 ± 3.6; body mass: 73 ± 15; body mass index: 27 ± 3), were assigned to control (CTL; n: 76) and exercise groups (RT; n: 81). The CTL group was divided according to the iron treatment received: without iron treatment (CTL-none; n = 19), treated only with iron sulfate or EPO (CTL-EPO or IRON; n = 19), and treated with both iron sulfate and EPO (CTL-EPO + IRON; n = 76). The RT group followed the same pattern: (RT-none; n = 20), (RT-EPO or IRON; n = 18), and (RT-EPO + IRON; n = 86). RT consisted of 24 weeks/3 days per week at moderate intensity of full-body resistance exercises prior to the hemodialysis section. The RT group, regardless of the iron treatment, improved iron metabolism in older individuals with ESRD. These results provide some clues on the effects of RT and its combination with EPO and iron sulfate in this population, highlighting RT as an important coadjutant in ESRD-iron deficiency.

Indirect Markers of Muscle Damage Throughout the Menstrual Cycle.

CONTEXT: The indirect markers of muscle damage have been previously studied in females. However, inconclusive results have been found, possibly explained by the heterogeneity regarding monitoring and verification of menstrual-cycle phase. PURPOSE: To determine whether the fluctuations in sex hormones during the menstrual cycle influence muscle damage. METHODS: A total of 19 well-trained eumenorrheic women (age 28.6 [5.9] y; height 163.4 [6.1] cm; weight 59.6 [5.8] kg body mass) performed an eccentric-based resistance protocol consisting of 10 × 10 back squats at 60% of their 1-repetition maximum on the early follicular phase (EFP), late follicular phase, and midluteal phase of the menstrual cycle. Range of motion, muscle soreness, countermovement jump, and limb circumferences were evaluated prior to 24 and 48 hours postexercise. Perceived exertion was evaluated after each set. RESULTS: Differences in sex hormones indicated that tests were adequately performed in the different menstrual-cycle phases. Prior to exercise, muscle soreness was higher in the EFP (4.7 [7.7]) than in the late follicular phase (1.1 [3.2]; P = .045). No other variables showed significant differences between phases. Time-point differences (baseline, 24, and 48 h) were observed in knee range of motion (P = .02), muscle soreness, countermovement jump, and between sets for perceived exertion (P < .001). CONCLUSION: Although the protocol elicited muscle damage, hormonal fluctuations over the menstrual cycle did not seem to affect indirect markers of muscle damage, except for perceived muscle soreness. Muscle soreness was perceived to be more severe before exercise performed in EFP, when estrogen concentrations are relatively low. This may impair women's predisposition to perform strenuous exercise during EFP.