Training-Related Changes in Force-Power Profiles: Implications for the Skeleton Start

Int J Sports Physiol Perform. 2018 Apr 1;13(4):412-419. doi: 10.1123/ijspp.2017-0110. Epub 2018 May 9.

Abstract

Purpose: Athletes' force-power characteristics influence sled velocity during the skeleton start, which is a crucial determinant of performance. This study characterized force-power profile changes across an 18-month period and investigated the associations between these changes and start performance.

Methods: Seven elite- and 5 talent-squad skeleton athletes' (representing 80% of registered athletes in the country) force-power profiles and dry-land push-track performances were assessed at multiple time points over two 6-month training periods and one 5-month competition season. Force-power profiles were evaluated using an incremental leg-press test (Keiser A420), and 15-m sled velocity was recorded using photocells.

Results: Across the initial maximum strength development phases, increases in maximum force (Fmax) and decreases in maximum velocity (Vmax) were typically observed. These changes were greater for talent (23.6% and -12.5%, respectively) compared with elite (6.1% and -7.6%, respectively) athletes. Conversely, decreases in Fmax (elite -6.7% and talent -10.3%) and increases in Vmax (elite 8.1% and talent 7.7%) were observed across the winter period, regardless of whether athletes were competing (elite) or accumulating sliding experience (talent). When the training emphasis shifted toward higher-velocity, sprint-based exercises in the second training season, force-power profiles seemed to become more velocity oriented (higher Vmax and more negative force-velocity gradient), which was associated with greater improvements in sled velocity (r = .42 and -.45, respectively).

Conclusions: These unique findings demonstrate the scope to influence force-power-generating capabilities in well-trained skeleton athletes across different training phases. To enhance start performance, it seems important to place particular emphasis on increasing maximum muscle-contraction velocity.

Keywords: athletes; ice track; leg press; neuromuscular adaptation.

MeSH terms

  • Adaptation, Physiological
  • Adult
  • Athletic Performance / physiology*
  • Competitive Behavior / physiology
  • Female
  • Humans
  • Leg / physiology
  • Male
  • Muscle Strength / physiology
  • Physical Conditioning, Human / methods*
  • Resistance Training / methods*
  • Running / physiology
  • Sports / physiology*
  • Young Adult