Int J Sports Physiol Perform. 2021 Dec 1;16(12):1786-1793. doi: 10.1123/ijspp.2020-0881. Epub 2021 May 21.
We tested whether a single session of heavy-load resistance priming conducted in the morning improved double-poling (DP) performance in the afternoon.
Eight national-level male cross-country skiers (mean [SD]: 23 [3] y, 184 [6] cm, 73 [7] kg, maximum oxygen consumption = 69 [6] mL·kg-1·min-1) carried out 2 days of afternoon performance tests. In the morning, 5 hours before tests, subjects were counterbalanced to either a session of 3 × 3 repetitions (approximately 85%-90% 1-repetition maximum) of squat and sitting pullover exercises or no exercise. The performance was evaluated in DP as time to exhaustion (TTE) (approximately 3 min) on a treadmill and 30-m indoor sprints before and after TTE (30-m DP pre/post). Furthermore, submaximal DP oxygen cost, countermovement jump, and isometric knee-extension force during electrical stimulation were conducted. Participants reported perceived readiness on test days.
Resistance exercise session versus no exercise did not differ for TTE (approximately 3 min above) (mean ± 95% confidence interval = 3.6% ± 6.0%; P = .29; effect size [ES], Cohen d = 0.27), 30-m DP pre (-0.56% ± 0.80%; P = .21; ES = 0.20), 30-m DP post (-0.18% ± 1.13%; P = .76; ES = 0.03), countermovement jump (-2.0% ± 2.8%; P = .21; ES = 0.12), DP oxygen cost (-0.13% ± 2.04%; P = .91; ES = 0.02), or perceived readiness (P ≥ .11). Electrical stimulation force was not different in contraction or relaxation time but revealed low-frequency fatigue in the afternoon for the resistance exercise session only (-12% [7%]; P = .01; ES = 1.3).
A single session of heavy-load, low-volume resistance exercise in the morning did not increase afternoon DP performance of short duration in high-level skiers. However, leg low-frequency fatigue after resistance priming, together with the presence of small positive effects in 2 out of 3 DP tests, may indicate that the preconditioning was too strenuous.
我们测试了在上午进行一次大负荷阻力预训练是否能提高下午的双支撑（DP）表现。
8 名国家级男子越野滑雪运动员（平均[标准差]：23[3]岁，184[6]厘米，73[7]公斤，最大摄氧量=69[6]毫升·千克-1·分钟-1）进行了 2 天的下午表现测试。在上午，测试前 5 小时，受试者平衡到 3 组 3 次重复（约 85%-90%1 次重复最大）的深蹲和坐姿过顶练习或无练习。表现通过在跑步机上的耐力测试（大约 3 分钟）和耐力测试前后的 30 米室内短跑（30 米 DP 前/后）进行评估。此外，还进行了亚最大 DP 耗氧量、深蹲跳和电刺激下的等长膝关节伸展力。参与者在测试日报告了准备情况。
阻力运动组与无运动组的耐力测试（大约 3 分钟以上）（平均[95%置信区间] = 3.6%[6.0%]；P =.29；效应量[ES]，Cohen d = 0.27）、30 米 DP 前（-0.56%[0.80%]；P =.21；ES = 0.20）、30 米 DP 后（-0.18%[1.13%]；P =.76；ES = 0.03）、深蹲跳（-2.0%[2.8%]；P =.21；ES = 0.12）、DP 耗氧量（-0.13%[2.04%]；P =.91；ES = 0.02）或准备情况（P ≥.11）没有差异。电刺激力在收缩或放松时间上没有差异，但仅在阻力运动组中下午出现低频疲劳（-12%[7%]；P =.01；ES = 1.3）。
上午进行一次大负荷、低容量的阻力运动训练并没有提高高水平滑雪运动员下午短时间 DP 的表现。然而，阻力预训练后的腿部低频疲劳，加上 3 项 DP 测试中有 2 项出现小的正效应，可能表明预处理过于剧烈。
