Kinematic alterations after two high-intensity intermittent training protocols in endurance runners

Abstract

PurposeThis study aimed to evaluate running kinematic characteristics during the early and late stages of 2 high-intensity intermittent training (HIIT) protocols with similar external load but different average running pace, as well as to compare the fatigue-induced changes during both HIIT protocols at a kinematic level.MethodsEighteen endurance runners were tested on a track on 2 occasions: 10 runs of 400 m with 90–120 s recovery between running bouts (10 × 400 m), and 40 runs of 100 m with 25–30 s recovery between running bouts (40 × 100 m). Heart rate was monitored during both protocols; blood lactate accumulation and rate of perceived exertion were recorded after both exercises. A high-speed camera was used to measure sagittal-plane kinematics at the first and last runs during both HIIT protocols. The dependent variables were spatial-temporal parameters (step length and contact and flight time), joint angles during support (relative angles of the hip, knee, and ankle), and foot strike pattern.ResultsHigh levels of exhaustion were reached by the athletes during both workouts (blood lactate accumulation >12 mmol/L, rate of perceived exertion >15; peak heart rate (HRpeak) > 176 bpm). A within-protocol paired t test (first vs. last run) revealed no significant changes (p ≥ 0.05) in kinematic variables during any of the HIIT sessions. A between-protocol comparison with the first run of each protocol revealed the effect of running speed on kinematics: +2.44 km/h during the 40 × 100 m: shorter contact and flight time (p ≤ 0.01) and longer step length (p = 0.001); greater hip flexion (p = 0.031) and ankle extension (p = 0.001) at initial contact; smaller knee and ankle flexion (p < 0.001) at midstance; and greater hip extension at toe-off (p < 0.001).ConclusionHIIT sessions including runs for 15–90 s and performed at intensity above the velocity associated with maximal oxygen uptake did not consistently perturb the running kinematics of trained endurance runners.

Running mechanics adjustments to perceptually-regulated interval runs in hypoxia and normoxia

“…In general, running mechanics pattern remained largely unaffected between early and late stages (i.e., from first to last interval) of our proposed HIIE, a finding also reported elsewhere. 4,22,23 For instance, intense interval training session consisting of either 10 runs of 400 m (rest = 60-180 s) or 40 runs of 100 m (rest = 25-30 s) did not modify the running kinematics of well-trained male runners. 4,23 However, having individuals constrained to run at a set velocity during fatigued running lacks ecological validity.…”

“…4,22,23 For instance, intense interval training session consisting of either 10 runs of 400 m (rest = 60-180 s) or 40 runs of 100 m (rest = 25-30 s) did not modify the running kinematics of well-trained male runners. 4,23 However, having individuals constrained to run at a set velocity during fatigued running lacks ecological validity. 10 Our spring-mass model results are partially in accordance with previous observation of modified mechanical behaviour towards lower vertical stiffness but constant leg stiffness during intervaltraining treadmill runs.…”

Validity and Reliability of 2-Dimensional Video-Based Assessment to Analyze Foot Strike Pattern and Step Rate During Running: A Systematic Review

“…Only 2 studies 10,18 reported adequately the inclusion and exclusion criteria used. One study 6 did not use adequate statistical analysis and 6 studies 4,6,12,13,19,29 omitted information on inclusion and exclusion criteria.…”

“…Despite the methodological rigor of our systematic review, we recognize several limitations of this study. First, 62.5% of the studies included in this systematic review 6,12,13,18,19 reported the psychometric properties of the 2D video analysis as a secondary objective. Therefore, relevant discussions on the psychometric properties of the 2D video analysis were not provided.…”

Relationships between Foot Morphology and Foot Muscle Strength in Healthy Adults

“…About five million years ago, humans further evolved and developed complex foot morphological characteristics (e.g., heel, arch, and enlarged first metatarsal bone) to adapt to the needs of various activities, such as upright standing, walking, and endurance running [1]. As the direct complex contact area between the lower extremities and the ground/interface, the human foot plays an important role in supporting body mass in both static and dynamic upright locomotion [2,3] and is controlled by intrinsic and extrinsic foot muscles [4]. On account of the complexity of the foot structure, morphological parameters (e.g., foot length, foot width, foot arch height) have been utilized to simplify the anatomical complexities of the foot and describe foot type in the clinical field [5,6].…”