Gejl Kasper Degn, Andersson Erik P, Nielsen Joachim, Holmberg Hans-Christer, Ørtenblad Niels
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
Front Physiol. 2020 Jul 7;11:810. doi: 10.3389/fphys.2020.00810. eCollection 2020.
Little is presently known about the effects of acute high-intensity exercise or training on release and uptake of Ca by the sarcoplasmic reticulum (SR). The aims here were to characterize this regulation in highly trained athletes following (1) repeated bouts of high-intensity exercise and (2) a period of endurance training including high-intensity sessions. Eleven cross-country skiers (25 ± 4 years, 65 ± 4 mL O⋅kg⋅min) performed four self-paced sprint time-trials (STT 1-4) lasting ≈ 4 min each (STT 1-4) and separated by 45 min of recovery; while 19 triathletes and road cyclists (25 ± 4 years, 65 ± 5 mL O⋅kg⋅min) completed 4 weeks of endurance training in combination with three sessions of high-intensity interval cycling per week. Release (μmol⋅g prot⋅min) and uptake [tau (s)] of Ca by SR vesicles isolated from m. and m. were determined before and after STT 1 and 4 in the skiers and in m. before and after the 4 weeks of training in the endurance athletes. The Ca release rate was reduced by 17-18% in both limbs already after STT 1 (arms: 2.52 ± 0.74 to 2.08 ± 0.60; legs: 2.41 ± 0.45 to 1.98 ± 0.51, < 0.0001) and attenuated further following STT 4 (arms: 2.24 ± 0.67 to 1.95 ± 0.45; legs: 2.13 ± 0.51 to 1.83 ± 0.36, < 0.0001). Also, there was a tendency toward an impairment in the SR Ca uptake from pre STT1 to post STT4 in both arms and legs (arms: from 22.0 ± 3.7 s to 25.3 ± 6.0 s; legs: from 22.5 ± 4.7 s to 25.5 ± 7.7 s, = 0.05). Endurance training combined with high-intensity exercise increased the Ca release rate by 9% (1.76 ± 0.38 to 1.91 ± 0.44, = 0.009), without altering the Ca uptake (29.6 ± 7.0 to 29.1 ± 8.7 s; = 0.98). In conclusion, the Ca release and uptake rates by SR in exercising limbs of highly trained athletes declines gradually by repetitive bouts of high-intensity exercise. We also demonstrate, for the first time, that the SR Ca release rate can be enhanced by a specific program of training in highly trained athletes, which may have important implications for performance parameters.
目前，关于急性高强度运动或训练对肌浆网（SR）钙释放和摄取的影响，人们知之甚少。本研究的目的是在高水平运动员中，对（1）重复进行高强度运动和（2）包括高强度训练阶段的耐力训练后的这种调节进行表征。11名越野滑雪运动员（25±4岁，65±4 mL O₂·kg⁻¹·min⁻¹）进行了4次自定节奏的短距离冲刺计时赛（STT 1 - 4），每次持续约4分钟（STT 1 - 4），中间间隔45分钟恢复时间；而19名铁人三项运动员和公路自行车运动员（25±4岁，65±5 mL O₂·kg⁻¹·min⁻¹）完成了4周的耐力训练，并每周进行3次高强度间歇骑行。在滑雪运动员的STT 1和4前后，以及耐力运动员训练4周前后，分别测定从肱二头肌和股外侧肌分离的SR囊泡对钙的释放（μmol·g蛋白⁻¹·min⁻¹）和摄取[时间常数（τ，s）]。在STT 1后，双臂和双腿的钙释放率均降低了17 - 18%（手臂：从2.52±0.74降至2.08±0.60；腿部：从2.41±0.45降至1.98±0.51，P < 0.0001），在STT 4后进一步降低（手臂：从2.24±0.67降至1.95±0.45；腿部：从2.13±0.51降至1.83±0.36，P < 0.0001）。此外，从STT 1前到STT 4后，双臂和双腿的SR钙摄取均有受损趋势（手臂：从22.0±3.7秒增至25.3±6.0秒；腿部：从22.5±4.7秒增至25.5±7.7秒；P = 0.05）。耐力训练与高强度运动相结合使钙释放率提高了9%（从1.76±0.38增至1.91±0.44，P = 0.009），而钙摄取未改变（从29.6±7.0秒降至29.1±8.7秒；P = 0.98）。总之，高水平运动员运动肢体中SR的钙释放和摄取率会因重复进行高强度运动而逐渐下降。我们还首次证明，通过特定的训练方案可以提高高水平运动员的SR钙释放率，这可能对运动表现参数具有重要意义。
