This study examined the effects of beetroot juice (BTJ) on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA) (2 × 250 mL) for 3 days after an initial repeated sprint test (20 × 30 m; RST1) and after a second repeated sprint test (RST2), performed 72 h later. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), reactive strength index (RI), pressure-pain threshold (PPT), creatine kinase (CK), C-reactive protein (hs-CRP), protein carbonyls (PC), lipid hydroperoxides (LOOH) and the ascorbyl free radical (A•−) were measured before, after, and at set times between RST1 and RST2. CMJ and RI recovered quicker in BTJ compared to PLA after RST1: at 72 h post, CMJ and RI were 7.6% and 13.8% higher in BTJ vs. PLA, respectively (p < 0.05). PPT was 10.4% higher in BTJ compared to PLA 24 h post RST2 (p = 0.012) but similar at other time points. No group differences were detected for mean and fastest sprint time or fatigue index. MIVC, or the biochemical markers measured (p > 0.05). BTJ reduced the decrement in CMJ and RI following and RST but had no effect on sprint performance or oxidative stress.

This study aims to investigate (i) how monozygotic (MZ) twin pairs who are discordant for body mass index (BMI) differ for objectively and subjectively measured physical activity (PA) and cardiorespiratory fitness (VO max) and (ii) associations of PA and VO max with adiposity and measures of metabolic health, in individual twins and independent of genetic and shared environmental effects within twin pairs. We examined 27 BMI-discordant and 14 BMI-concordant MZ twin pairs. Fat and fat-free mass (ffm) were measured by dual-energy X-ray absorptiometry and VO max by spiroergometry. PA was measured objectively by accelerometers using ActiGraph GT1M for daytime activity and Actiwatch AW7 for 24 h/d. Self-reported PA was obtained through the Baecke and IPAQ long-form questionnaires. Objectively measured moderate-to-vigorous PA (MVPA, min/d), steps/d, and VO max/kg were significantly lower, by 30%, 21%, and 14%, respectively, in the heavier compared with the leaner co-twins of the BMI-discordant twin pairs. There were no significant differences in self-reported PA or VO max/ffm. As expected, PA and VO max/ffm were similar in the BMI-concordant co-twins. Furthermore, the 24-h recording of activity suggested that the heavier co-twins had more restless sleep during the night, whereas the leaner co-twins were more active during the day. Within all twin pairs, higher MVPA and steps per day were associated with lower fat percentage and improved metabolic health measures. Objectively, but not subjectively measured PA is associated with lower fat percentage and better metabolic health, independent of genetic and shared environmental factors.

22 33 particular. No significant behavioural differences emerged in BMI-concordant twin 34 pairs. Overeating -measured by "frequent overeating", "disinhibited eating", and 35 "binge-eating score" -was the main behavioural trait associated with higher BMI, 36 independent of genotype and shared environment.37 38

Background and aims: Plasma apolipoprotein C3 (ApoC3) is associated with higher plasma triglyceride and type 2 diabetes incidence. We evaluated whether body mass index (BMI) or glucose metabolism were associated with ApoC3 in healthy monozygotic (MZ) twins. Methods and Results: Forty-seven MZ twin-pairs (20 man, 27 women), aged 23e42 years, were divided in subgroups according to discordance or concordance for (a) BMI (within-pair difference (D) in BMI!3.0 or<3.0 kg/m 2 ), or (b) 2-h glucose iAUC, during oral glucose tolerance test (DGlucose iAUC !97.5 or<97.5 mmol  120 minutes). Within these discordant or concordant subgroups, we tested (Wilcoxon signed-rank test) co-twin differences in ApoC3, adiposity measures, insulin-resistance and beta-cell function indices, and plasma and lipoprotein lipids.In BMI-Discordant (p Z 0.92) or BMI-Concordant (p Z 0.99) subgroups, ApoC3 did not differ between leaner and heavier co-twins. In the GlucoseeDiscordant subgroup, ApoC3 was significantly higher in twins with higher Glucose iAUC than in their co-twins with the lower Glucose iAUC (10.03 AE 0.78 vs. 8.48 AE 0.52 mg/dl; M AE SE; p Z 0.032). Co-twins with higher Glucose iAUC also had higher waist circumference, body fat percentage, liver fat content, worse insulin-sensitivity and beta-cell function and higher cholesterol and triglyceride in plasma VLDL, IDL, and LDL. In GlucoseeConcordant twin-pairs, no significant differences were observed in the explored variables. In all twin-pairs, DApoC3 correlated with D in lipids and glucose metabolism variables, the closest relationship being between DApoC3 and DVLDL triglyceride (r Z 0.74, p < 0.0001). Conclusions: While ApoC3 was not related to acquired differences in BMI, it associated with early dysregulation of glucose metabolism independently of obesity and genetic background.

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ObjectiveWe investigated 36-year body mass index (BMI) trajectories in twins whose BMI in young adulthood was below, within, or above their genetically expected BMI, with a focus on twin pairs with large intrapair BMI differences (within-pair ΔBMI ≥ 3 kg/m2).MethodsTogether, 3227 like-sexed twin pairs (34% monozygotic [MZ]) were examined at age ∼30 in 1975 and followed up in 1981, 1990, and 2011. In 1975, the observed BMI of an individual was considered either within (±2.0 kg/m2), below (<-2.0 kg/m2), or above (>+2.0 kg/m2) genetically expected BMI, measured by a polygenic risk score of 996,919 single nucleotide polymorphisms.ResultsIn MZ and DZ twin pairs with large intrapair BMI differences, the co-twin with a higher observed BMI in 1975 deviated above expected BMI more frequently (∼2/3rd) than the co-twin with a lower BMI deviated below expectation (∼1/3rd). Individuals below, within, and above expectation in 1975 reached, respectively, normal weight, overweight, and obesity by 2011, with a mean BMI increase of 4.5 (95% confidence interval 4.3 to 4.8) kg/m2.ConclusionCategorizing BMI as below, within, or above PRS-predicted BMI helps identifying individuals who have been resistant or susceptible to weight gain. This may provide new insights into determinants and consequences of obesity.

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