ECSS Paris 2023: OP-PN19
INTRODUCTION: Metabolic dysfunction–associated steatotic liver disease (MASLD) affects ~30% of the global population and is strongly associated with obesity and metabolic syndrome (MetS). Time-restricted eating (TRE) and resistance training (RT) independently improve metabolic health, but their combined effects on hepatic fat content (HFC) and glycemic control remain unclear. This study investigates the synergistic impact of TRE and RT on HFC and glycemic markers in patients with MetS, independent of weight loss. METHODS: The TERA study, a 10-week randomized controlled trial (RCT), included 76 overweight/obese adults (40-60 years) with MetS, who were randomized into TRE alone (n=26), RT with a normal diet (ND+RT, n=25), and TRE combined with RT (TRE+RT, n=25). The TRE diet limited food intake between 12:00 PM and 8:00 PM, whereas the ND group adhered to a standard eating pattern without time restrictions. All groups adhered to iso-caloric diets with a protein intake of 1.5 g/kg/day. RT sessions were conducted with up to three participants and supervised three times per week. Each 60-minute session included a full-body workout consisting of nine exercises targeting major muscle groups. HFC, measured by magnetic resonance spectroscopy, and glycemic markers were assessed pre- and post-intervention. Data were analyzed using ANCOVA, with baseline values as covariates, and logistic regression was applied for dichotomous variables. RESULTS: Of the initial 76 participants, 68 completed the study: 22 in the TRE alone, 22 in the ND+RT, and 23 in the TRE+RT groups. Following the 10-week intervention, although weight loss was minimal in all groups (0-1.6 kg), significant differences were observed between ND+RT and both TRE alone (1.8 kg, p = 0.01) and TRE+RT (1.57 kg, p = 0.01), with no difference between TRE alone and TRE+RT (0.25 kg, p = 0.57). Compared to TRE alone (-4.6%±6.4, relative change -24.3%±29.6), HFC reductions was significantly greater for the TRE+RT group (-7.1% ± 7.7, relative change -41.1% ± 31.6, p<0.05 for both), but not for the ND+RT (-5.5% ± 6.8, relative change -32.6% ± 27.6). A >30% reduction in HFC was achieved by 73.9% of participants in the TRE+RT group compared to 59.1% in the ND+RT group (p=0.23) and 40.9% in the TRE group (p = 0.028). The TRE+RT achieved the largest reductions in insulin (-5.2 ± 10.2 µU/ml) and HbA1c (-0.07 ± 0.12%), followed by moderate reductions in the ND+RT group (insulin: -2.6 ± 12.7 µU/ml; HbA1c: -0.07 ± 0.27%), and minimal changes with TRE alone (insulin: -0.97 ± 9.5 µU/ml; HbA1c: -0.03 ± 0.24%). However, none of these differences reached statistical significance compared to TRE alone. CONCLUSION: In overweight/obese adults with MetS, TRE+RT demonstrated significantly greater reductions in HFC compared to TRE alone, independent of substantial weight loss. These findings highlight the distinct advantages of combining TRE with RT for managing MASLD and emphasize the role of RT in HFC reduction, potentially mediated by improved insulin sensitivity.
Read CV Ron SternfeldECSS Paris 2023: OP-PN19
INTRODUCTION: Problematic Low Energy Availability (LEA) can result in Relative Energy Deficiency in Sport (REDs) which has multiple adverse health effects. Research investigating its impact on cardiovascular health is limited and conflicting, but suggests problematic LEA is associated with unfavourable lipid profiles and endothelial dysfunction. To date no studies have investigated the cardiovascular effects amongst elite team sport players. METHODS: Eighteen players of Māori or Pacifica descent who were part of the Olympic women’s 7s squad participated in this study. The Low Energy in Females Questionnaire (LEAF-Q) was used to group players as at risk or not at risk of LEA. Blood samples were collected and measured for plasma lipids, and inflammatory markers. Arterial stiffness was measured by pulse wave velocity (PWV) (SphygmoCor Xcel PWV and PWA system, AtCor, Medical Pty Ltd). Energy intakes were obtained via three day diet records, which were analysed via Foodworks using the New Zealand database. Independent sample t-tests were performed, significance set at p≤0.05. Results are presented as mean ±standard deviation, mean difference(95% confidence intervals). RESULTS: Similar to other research ten (55%) players were classed as at risk of LEA. Those at risk of LEA had a significantly lower energy intake (8053±1,999 kJ vs 11,072±1,951 kJ, p=0.05). Low-density lipoprotein was moderately higher by 11.3% in those at risk (2.42± 0.75 mmol.L-1 vs 2.14±0.45 mmol.L-1, 0.15 (95%CI: 0.73, -0.43)mmol.L-1) p=0.19. Whereas high-density lipoprotein concentrations were 10.7% lower, but not statistically different between groups (1.50±1.31 vs 1.64± 0.44 mmol.L-1, 0.29 (95% CI: 0.07, -0.65) mmol.L-1 p=0.31). There was no statistically significant differences for ApoA nor ApoB, p>0.05. There was a small elevation pulse wave velocity (6.55 ± 1.54) ms-1 for those at risk compared to not at risk 5.69 ± 1.11 ms-1 (0.86 ms-1 (2.40, -0.68) p=0.22). CONCLUSION: There is a small body of literature suggesting athletes at risk of LEA have different blood lipid profiles compared to those not at risk. It is plausible that decreases in estrogen seen with REDs are responsible for changes in plasma lipids. However, not all studies have shown differences in lipid profiles. The results from the current study were not significantly different, but may have some clinical relevance. The large standard deviations and small sample size likely contribute to the lack of statistical findings, but this study does reflect the small pool of elite female 7s players. This study shows female 7s players at risk of LEA which may impact their cardiovascular health. Therefore, all involved in Rugby 7s should be aware of REDs. Further, specialist medical teams should lead diagnosis and treatment, as signs of REDs can also signify other health conditions.
Read CV Katherine BlackECSS Paris 2023: OP-PN19
INTRODUCTION: Obesity and reduced physical activity are closely associated with impaired insulin sensitivity and glucose regulation. High intensity interval training (HIIT) increases reliance on muscle glycogen, and consequently results in improved insulin sensitivity. Consequently, HIIT in hypoxia may enhance these effects. Accordingly, the aim of this research was to investigate the chronic effects of a 10-week HIIT intervention in hypoxia on insulin sensitivity and glucose regulation in sedentary individuals with overweight and obesity. METHODS: 30 sedentary individuals with overweight or obesity (36±7 yrs, BMI 33.9±6.5, body fat percentage: 40.2±7.0%) underwent 10 weeks (3 session/week) of exercise training which consisted of 2 weeks of standardised training in normoxia followed by 8 weeks of HIIT training with (HYP) or without hypoxia (NOR). Each session consists of four to six, 1-min cycling bouts performed at a rating of perceived exertion (RPE) of 16 interspersed with 4-min of recovery at RPE 10, and resistance exercise (comprising 4 different exercises, always performed in normoxic conditions). Body composition and glucose tolerance (via an oral glucose tolerance test; OGTT) was examined before and after the 10-week training program. The primary analyses included all data irrespective of dropouts and completeness of outcome measures (intention to treat). Linear mixed method models were used with condition, time, and interaction defined as the fixed effects and participants as random effects. RESULTS: Results There was no significant effect on glucose area under the curve (AUC) during the OGTT in either condition (pre-post diff: HYP: -47±131mmol/L/120min; NOR: +31±92mmol/L/120min, p=.55). Within-group differences in insulin AUC was reduced after training in HYP (-1346±2209mU/L/120min, p=.03, g=0.26) but not NOR (-270±1165 mU/L/120min, p=.28, g=0.11) with no difference between groups (p=.73). Insulin AUC normalised for glucose AUC was not significantly different in either condition. There was no difference in insulin resistance (HOMA2-IR) following training in both groups (HYP: 1.34 vs 1.38; NOR: 1.12 vs 1.06, p=.41, g=0.03). Within group differences in fat mass (FM) and fat free mass (FFM) were reduced and increased, respectively in HYP (FM: -0.97±1.89kg, p=.03; FFM: +1.89±2.6kg, p=.04) but not NOR (-0.51±2.85kg, p=.29; FFM: +0.21±1.76kg, p=.36). CONCLUSION: Perceptually regulated HIIT performed in hypoxia demonstrated a tendency for improvement in body composition compared to matched training in normoxia. Additionally, reductions in insulin AUC suggest an improvement in insulin sensitivity, although this did not reach statistical significance. Participants were however, normoglycemic at baseline, possibly limiting substantial changes in metabolic outcomes. Future studies are needed to investigate the efficacy of HIIT in hypoxia on glycemic control in individuals with impaired glycemic function.
Read CV Jacky SooECSS Paris 2023: OP-PN19