Department of Physical Performance, The Norwegian School of Sport Sciences, Ullevål Stadion, Post box 4014, 0806, Oslo, Norway.
The Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway.
Eur J Appl Physiol. 2019 Dec;119(11-12):2579-2587. doi: 10.1007/s00421-019-04237-z. Epub 2019 Sep 30.
Previous studies have found an acute performance improvement with longer pole lengths in double poling (DP) at low-to-moderate speeds. We investigated the influence of pole lengths (PL) on O-cost, 3D kinematics, and performance in DP at moderate-to-high speeds before (Pre) and after (Post) eight training sessions with long poles on a rollerski treadmill.
Seven male and four female skiers completed tests with two different PLs (84 and 90% of body height). Submaximal O-cost (1º; 4.5 [females] or 6 m s [males]) and a peak velocity test (1º; ∼ 7.3 m s) were assessed before and after a six week training period. The training sessions consisted of 50 min of low-moderate intensity training and 4 × 10 s maximal sprints with PL.
On average for all tests, PL induced 1.0 ± 1.0% higher peak velocity compared to PL (mean ± CI) with no difference in vertical displacement of center of mass (COM). From Pre to Post, peak velocity and cycle time were increased and the displacement of COM were reduced similarly for both PLs. At moderate speed, PL induced less displacement of COM with subsequent 1.1 ± 0.7% lower O-cost compared to PL. From Pre to Post, the O-cost and COM were reduced similarly for both PLs.
Longer PL than skiers self-selected lengths reduce O-cost at moderate speeds, but induced lower peak velocity. Eight sessions of training with PL90% did not influence the difference between PL and PL on O-cost, kinematics or peak velocity.
先前的研究发现,在低至中等速度下,双支撑(DP)的撑杆长度越长,急性表现会提高。我们研究了在使用滚轴式跑步机上的长杆进行 8 次训练后,撑杆长度(PL)对 DP 中中高速下的 O 成本、3D 运动学和性能的影响。
7 名男性和 4 名女性滑雪者使用两种不同的 PL(身高的 84%和 90%)完成了测试。在 6 周的训练期前后,评估了 1 度的亚最大 O 成本(1º;4.5 [女性]或 6 m s [男性])和峰值速度测试(1º;约 7.3 m s)。训练课程包括 50 分钟的低强度训练和 4 次 10 秒的最大冲刺,使用 PL。
在所有测试中,平均而言,PL 比 PL 高出 1.0±1.0%的峰值速度,但质心(COM)的垂直位移没有差异。从 Pre 到 Post,峰值速度和周期时间增加,COM 的位移减少,两种 PL 都有相似的变化。在中等速度下,PL 诱导 COM 的位移较小,随后 O 成本降低 1.1±0.7%。从 Pre 到 Post,两种 PL 的 O 成本和 COM 都有相似的降低。
比滑雪者自我选择长度更长的 PL 可以降低中等速度下的 O 成本,但会降低峰值速度。8 次使用 PL90%的训练不会影响 PL 与 PL 之间的 O 成本、运动学或峰值速度的差异。