Blood lactate responses to leg presses performed against inertial resistance.
BACKGROUND
A flywheel ergometer has been devised which employs gravity-independent inertial resistance. Concentric and eccentric actions, which are integral to weight-bearing and ambulation activities, may be done on this ergometer. However, blood lactate responses to exercise on the ergometer by contractile mode and training volume are unknown.


METHODS
Workout order was balanced so that subjects performed each type of ergometer leg press workout twice in a nonsequential manner. Per workout, 10 repetitions were performed per set. Workouts were as follows: three sets with concentric and eccentric (CE3) actions, three sets with concentric-only (CO3) actions, and six sets with concentric-only (CO6) actions. Pre- and 5-min post-exercise lactate was measured from a fingertip blood drop. Lactate means were compared with a 2 x 3 (time X workout) ANOVA with repeated measures applied to both independent variables and Scheffe's post hoc test. With body mass and performance measures as predictor variables, multivariate regression attempted to explain post-exercise and delta (post-pre) lactate variance.


RESULTS
Post-exercise blood lactate values (mmol x L(-1), mean +/- SEM) were as follows: CE3, 8.08 +/- 0.44; CO3, 7.57 +/- 0.49; and CO6, 6.96 +/- 0.43. CE3 and CO6 workouts produced comparable volumes of work. Though several CE3 performance measures were significantly correlated to post-exercise and delta lactate values, power indices had the strongest relationship.


CONCLUSIONS
Factors related to lactate production and clearance caused CE3 values to be highest. Power indices were most correlated to lactate as they denote a higher work rate and reliance on glycolysis.
Caruso
John F
JF
Exercise and Sports Science Program, The University of Tulsa, Tulsa, OK 74104, USA. john-caruso@utulsa.edu
Herron
Jacquelyn C
JC
Capps
Landon B
LB
Coday
Michael A
MA
Ramsey
Charles A
CA
Drummond
Jan L
JL
D000328:Adult; D016552:Ergometry; D015444:Exercise / Q000502:physiology*; D005260:Female; D006019:Glycolysis / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D015999:Multivariate Analysis; D009119:Muscle Contraction / Q000502:physiology
D019344:Lactic Acid