title: Manipulation of step height and its effect on lactate metabolism during a one-minute anaerobic step test.
abstract: 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.
authors.affiliation: Department of Kinesiology, Exercise Physiology Laboratory, Exercise Science, California Baptist University, Riverside, California.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Nguyen
authors.forename: Trevor L
authors.initials: TL
authors.lastname: Gillum
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D019415:Torque; D055815:Young Adult
chemical_list: D019344:Lactic Acid