Metabolic effects of menopause: a cross-sectional characterization of body composition and exercise metabolism.

OBJECTIVES: To evaluate body composition, fat distribution, and metabolism at rest and during exercise in premenopausal, perimenopausal, and postmenopausal women. METHODS: This cross-sectional study in 72 women ages 35 to 60 years evaluated body composition via a fourcompartment model, fat distribution using dual-energy x-ray absorptiometry-derived android to gynoid ratio, metabolic measures via indirect calorimetry, and lifestyle factors using surveys. One-way analyses of variance and one-way analyses of covariance covaried for age and hormone levels (estrogen and progesterone) were used to compare groups. RESULTS: Body fat percent was significantly lower in premenopausal than perimenopausal women (mean difference ± standard error: - 10.29 ± 2.73%, P = 0.026) despite similarities in fat mass and fat-free mass between groups (P≥0.217). Android to gynoid ratio was significantly lower in premenopausal than perimenopausal women (MD ± SE: -0.16 ± 0.05 a.u., P = 0.031). Resting energy expenditure was similar between groups (P = 0.999). Fat oxidation during moderate intensity cycle ergometer exercise was significantly greater in premenopausal than postmenopausal women (MD ± SE: 0.09 ± 0.03 g/min, P = 0.045). The change in respiratory exchange ratio between rest and moderate intensity exercise was significantly lower in premenopausal women than peri- (MD ± SE: -0.05 ± 0.03 a.u., P = 0.035) and postmenopausal women (MD ± SE: -0.06 ± 0.03 a.u., P = 0.040). Premenopausal women reported significantly fewer menopause symptoms than peri- (MD ± SE: -6.58 ± 1.52 symptoms, P = 0.002) and postmenopausal participants (MD ± SE: -4.63 ± 1.52 symptoms, P = 0.044), while similarities between groups were observed for lifestyle factors including diet and physical activity (P>0.999). CONCLUSIONS: Perimenopause may be the most opportune window for lifestyle intervention, as this group experienced the onset of unfavorable body composition and metabolic characteristics. VIDEO SUMMARY: http://links.lww.com/MENO/A932.

Postexercise Inflammasome Activation and IL-1ß Production Mitigated by Flavonoid Supplementation in Cyclists.

Inflammasomes are multiprotein signaling platforms of the innate immune system that detect markers of physiological stress and promote the maturation of caspase-1 and interleukin 1 beta (IL-1ß), IL-18, and gasdermin D. This randomized, cross-over trial investigated the influence of 2-week mixed flavonoid (FLAV) versus placebo (PL) supplementation on inflammasome activation and IL-1ß and IL-18 production after 75-km cycling in 22 cyclists (42 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr postexercise (176 ± 5.4 min, 73.4 ± 2.0 %VO2max). The supplement (678 mg FLAVs) included quercetin, green tea catechins, and bilberry anthocyanins. The pattern of change in the plasma levels of the inflammasome adaptor oligomer ASC (apoptosis-associated speck-like protein containing caspase recruitment domain) was different between the FLAV and PL trials, with the FLAV ASC levels 52% lower (Cohen's d = 1.06) than PL immediately following 75-km cycling (interaction effect, p = .012). The plasma IL-1ß levels in FLAV were significantly lower than PL (23-42%; Cohen's d = 0.293-0.644) throughout 21 hr of recovery (interaction effect, p = .004). The change in plasma gasdermin D levels were lower immediately postexercise in FLAV versus PL (15% contrast, p = .023; Cohen's d = 0.450). The patterns of change in plasma IL-18 and IL-37 did not differ between the FLAV and PL trials (interaction effects, p = .388, .716, respectively). These data indicate that 2-week FLAV ingestion mitigated inflammasome activation, with a corresponding decrease in IL-1ß release in cyclists after a 75-km cycling time trial. The data from this study support the strategy of ingesting high amounts of FLAV to mitigate postexercise inflammation.

Effects of Whey and Pea Protein Supplementation on Post-Eccentric Exercise Muscle Damage: A Randomized Trial.

This randomized trial compared pea protein, whey protein, and water-only supplementation on muscle damage, inflammation, delayed onset of muscle soreness (DOMS), and physical fitness test performance during a 5-day period after a 90-min eccentric exercise bout in non-athletic non-obese males (n = 92, ages 18-55 years). The two protein sources (0.9 g protein/kg divided into three doses/day) were administered under double blind procedures. The eccentric exercise protocol induced significant muscle damage and soreness, and reduced bench press and 30-s Wingate performance. Whey protein supplementation significantly attenuated post-exercise blood levels for biomarkers of muscle damage compared to water-only, with large effect sizes for creatine kinase and myoglobin during the fourth and fifth days of recovery (Cohen's d > 0.80); pea protein versus water supplementation had an intermediate non-significant effect (Cohen's d < 0.50); and no significant differences between whey and pea protein were found. Whey and pea protein compared to water supplementation had no significant effects on post-exercise DOMS and the fitness tests. In conclusion, high intake of whey protein for 5 days after intensive eccentric exercise mitigated the efflux of muscle damage biomarkers, with the intake of pea protein having an intermediate effect.