ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1998 September;38(3):215-20

Copyright © 1999 EDIZIONI MINERVA MEDICA

language: English

Lactate production in response to maximal and submaximal StairMaster PT4000 and treadmill exercise

Schuler P. B. ¹, Martino M. ², Abadie B. R. ³, Stout T. W. ³, Conn P. T. ³, Wang M. Q. ⁴

¹ Department of Health Leisure and Sport, The University of West Florida, Pensacola, USA; ² Human Performance Laboratory, University of Southern Mississippi, Hattiesburg, USA; ³ Human Performance Laboratory, Mississippi State University, Mississippi State, USA; ⁴ Health Studies, The University of Alabama, Tuscaloosa, USA

Back­ground. The pur­pose of ­this ­study was to ­measure the ­amount of lac­tate pro­duced, as an indi­ca­tion of ­fatigue, in ­response to max­imal and submax­imal stair­stepper (SM) and tread­mill (TM) exer­cise.
­Methods. ­Thirty vol­un­teers (15 ­males, ­mean age 23 yrs; 15 ­females, ­mean age 22 yrs) com­pleted max­imal and submax­imal SM and TM pro­to­cols on ­four sep­arate ­visits to the labor­a­tory to deter­mine max­imal ­oxygen con­sump­tion (V.O2max), and ­blood lac­tate con­cen­tra­tions. Max­imal TM ­testing con­sisted of the ­Bruce pro­tocol, ­while the max­imal SM pro­tocol ­involved pro­gressing in incre­ments of 2 ­levels ­every 2 min­utes. ­Eight min­utes of sub­max­imal TM and SM exer­cise was per­formed at an inten­sity of 65% of V.O2max, as meas­ured ­during max­imal TM and SM ­testing. ­Fifty micro­li­ters of ­blood was col­lected via fin­ger­prick of the ­index ­finger ­prior to, and imme­di­ately ­post max­imal and submax­imal TM and SM exer­cise, and ­during min­utes 3, 5, and 7 of ­active ­recovery. Red ­blood ­cells ­were ­lysed and ana­lyzed imme­di­ately ­using the YSI #1500 ­Sport lac­tate ana­lyzer.
­Results. TM-VO2max, was sig­nif­i­cantly ­higher for ­both, ­males and ­females, com­pared to SM-V.O2max. ­Repeated meas­ured anal­yses of var­i­ance ­revealed sig­nif­i­cantly ­higher ­blood lac­tate ­levels ­during the ­same rel­a­tive submax­imal work­loads for SM com­pared to TM exer­cise.
Con­clu­sions. ­These find­ings sug­gest ­that an ­increased lac­tate pro­duc­tion ­during submax­imal SM exer­cise may ­result in ­early ­fatigue and, ­thereby, ­limit max­imal per­for­mance on the SM.