Blood Lactate and Hormonal Responses to Prototype Flywheel Ergometer Workouts

Abstract

The purpose of the study was to compare blood lactate and hormonal responses with flywheel ergometer (FERG) leg presses for preliminary assessment of workouts best suited for future in-flight resistance exercise. Comprised of 10 repetition sets, the workouts entailed 3 sets of concentric and eccentric (CE3) actions, or concentric-only actions done for 3 (CO3) or 6 (CO6) sets. Methods employed included assessment of blood lactate concentrations ([BLa-]) before and 5 minutes postexercise. Venous blood was also collected before and at 1 and 30 minutes postexercise to assess growth hormone, testosterone, cortisol concentrations ([GH], [T], [C]) and [T/C] ratios. [BLa-] were compared with 2 (time) x 3 (workout) analysis of variance. Hormones were assessed with 2 (gender) x 3 (time) x 3 (workout) analysis of covariances. Results showed [BLa-] had a time effect. Growth hormone concentration showed gender x workout, gender x time, and workout x time interactions, whereas [T] had a 3-way interaction. [C] had gender, time, and workout effects. [T/C] yielded a gender x time interaction. It was concluded that, because CO6 and CE3 yielded similar anabolic hormonal data but the latter had a lower [C] 30 minutes postexercise, CE3 served as the best workout. Although the FERG was originally designed for microgravity, the effort put forth by current subjects was like that for workouts aimed at greater athletic performance and conditioning. Practical applications suggest that eccentric actions should be used for FERG workouts geared toward muscle mass and strength improvement.

Lactate, cortisol and testosterone values from high-speed resistive exercise workouts done by women

“…Yet like our study, the running trial did see significant [C] changes [23]. For an ACTH-mediated [C] increase it appears a larger sample size, more intense workouts and/or a longer length of time (∼ 30 minutes) before post-exercise collection is required to evoke significant temporal changes when cortisol is measured from saliva [6,16,23,24].…”

“…Other studies also saw greater [C] in highly trained subjects [25], or those whom preceded such measurements with larger volumes of exercise [6,24]. With a within-subjects design, subjects [C] were measured before and after various leg press workouts [24].…”

“…With a within-subjects design, subjects [C] were measured before and after various leg press workouts [24]. Results showed workouts with the most concentric activity had significantly higher [C] values versus the other exercise bouts [24].…”

Endocrine alterations from concentric vs. eccentric muscle actions: A brief review

“…Finally, Carruso et al [60] used a flywheel device to determine anabolic hormone responses to male and females subjects performing 6 sets/10reps of flywheel activity for CON or 3 sets/10reps of flywheel activity CON + ECC actions, with equal total work performed for both groups. A third group performed 3 sets of CON only with approximately half the total work.…”

Human Testosterone and Lactate Values from Flywheel Ergometry: Effect of Contractile Mode and Work Volume

“…Yet exercise suppressed [T] during bed rest, a µg analog (Wade et al, 2005). Nonetheless, changes to [BLa -] foretell the workout's merits, as well as subsequent [T], and thus warrant inquiry (Caruso et al, 2010). Some believe exercise-induced increases in [T] are related to concurrent lactate production (Liu et al, 2009), while others imply the two operate independently (Kraemer et al, 1991).…”