Muscle transcriptome at rest and during recovery from running in elite male ultra-endurance athletes acclimated to a high-carbohydrate versus low-carbohydrate diet

Low-carbohydrate diets enhance lipid metabolism and decrease reliance on glucose oxidation in athletes, but the associated gene expression patterns remain unclear. To provide mechanistic insight, we investigated the skeletal muscle transcriptome in elite ultra-endurance athletes habitually consuming a high-carbohydrate (HC, n=10, 33±6y, VO2max=63.4±6.2 mL O2•kg-1•min-1) or low-carbohydrate (LC, n=10, 34±7y, VO2max=64.7±3.7 mL O2•kg-1•min-1) diet. Skeletal muscle gene expression was measured at baseline (BL), immediately-post (H0), and 2h (H2) after 3h submaximal treadmill running. Exercise induced a coordinated but divergent expression pattern. LC had higher expression of genes associated with lipid metabolism, particularly at BL. At H2, gene expression patterns were associated with differential pathway activity, including inflammation/immunity, suggesting a diet-specific influence on early muscle recovery. These results indicate that a habitual ketogenic diet leads to differences in resting and exercise-induced skeletal muscle gene expression patterns, underlying our previous findings of differential fuel utilization during exercise in elite male ultra-endurance athletes. Highly trained male ultra-endurance athletes acclimated to either high-carbohydrate or low-carbohydrate (ketogenic) diet performed a 3h treadmill run. Skeletal muscle gene expression was measured via RNA-seq on muscle biopsies collected at rest (baseline, BL), immediately post-exercise (h0), and two hours into early recovery (h2).

低碳水化合物饮食可提升运动员的脂质代谢水平，降低其对葡萄糖氧化的依赖，但相关基因表达模式仍不明晰。为阐明其潜在机制，本研究对习惯性采用高碳水化合物（HC，n=10，年龄33±6岁，最大摄氧量VO₂max=63.4±6.2 mL O₂·kg⁻¹·min⁻¹）或低碳水化合物（LC，n=10，年龄34±7岁，最大摄氧量VO₂max=64.7±3.7 mL O₂·kg⁻¹·min⁻¹）饮食的优秀超耐力运动员的骨骼肌转录组（transcriptome）进行了分析。分别在基线（BL）、3小时次极量跑台运动后即刻（H0）以及运动后2小时（H2）三个时间点检测骨骼肌基因表达水平。运动可诱导协调但具有分化特征的基因表达模式；LC组在脂质代谢相关基因的表达水平更高，尤其是在基线状态下。运动后2小时，基因表达模式与炎症/免疫等通路的差异化活化相关，提示饮食类型对骨骼肌早期恢复具有特异性影响。上述结果表明，习惯性生酮饮食会导致静息状态及运动诱导的骨骼肌基因表达模式产生差异，这也为我们此前在优秀男性超耐力运动员中观察到的运动过程中燃料利用差异化的研究结果提供了机制支撑。本研究中，适应高碳水化合物或低碳水化合物（生酮）饮食的高水平男性超耐力运动员完成了3小时次极量跑台运动；通过对静息时（基线，BL）、运动后即刻（h0）以及早期恢复阶段2小时（h2）采集的肌肉活检样本进行RNA测序（RNA-seq），检测骨骼肌基因表达水平。