Manipulation of step height and its effect on lactate metabolism during a one-minute anaerobic step test

• Published in: Journal of strength and conditioning research Vol. 29; no. 6; p. 1578
• Main Authors: Nguyen, Brian D, Gillum, Trevor L
• Format: Journal Article
• Language: English
• Published: United States 01.06.2015
• Subjects: Adult; Anaerobic Threshold - physiology; Biomechanical Phenomena; Cross-Sectional Studies; Exercise Test - methods; Female; Gait - physiology; Humans; Knee Joint - physiology; Lactic Acid - blood; Male; Torque; Young Adult
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/JSC.0000000000000789

The purpose of this study was to observe the effects of the 1-minute anaerobic step test on lactate production. In addition, a comparison of postexercise lactate levels between the traditional 40-cm step height and a modified 20-cm step height was tested along with multiple biomechanical components such as torque, knee angle, and power. A convenience sample of 9 healthy moderately trained individuals were recruited for this experiment. Each subject performed the 1-minute anaerobic step test in a counterbalanced, crossover, and repeated-measures design. They performed 2 trials, 1 with a 40-cm step height and another with a 20-cm step height. Results showed statistical significance in terms of the postexercise lactate concentration (40 cm: 8.04 ± 2.13 mmol·L(-1); 20 cm: 6.18 ± 2.62 mmol·L(-1)) and lactate production (40 cm: 5.36 ± 2.73 mmol·L(-1); 20 cm: 3.06 ± 2.96 mmol·L(-1)) between the 2 step heights (p ≤ 0.05). With a lowered step height, the moment arm decreased significantly, which lowered the torque placed on the knee joint. Knee angle and power both decreased with a lowered step height of 20 cm. These results suggest that the 1-minute anaerobic step test is effective at eliciting lactate and can be used as an anaerobic exercise modality to train the anaerobic energy system. Furthermore, a step height of 40 cm seemed to be more effective at taxing the anaerobic energy system and eliciting lactate compared with a step height of 20 cm.