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A Journal on Applied Physiology, Biomechanics, Preventive Medicine,
Sports Medicine and Traumatology, Sports Psychology

Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,111

Frequency: Monthly

ISSN 0022-4707

Online ISSN 1827-1928


The Journal of Sports Medicine and Physical Fitness 1998 June;38(2):116-23


Effect of lac­tate con­sump­tion on exer­cise per­for­mance

Bryner R. W., Hornsby W. G., Chetlin R., Ullrch I. H., Yeater R. A.

Departments of Exercise Physiology and Medicine, School of Medicine, West Virginia University, Morgantown, WV, USA

Background. Maintenance of plas­ma glu­cose is impor­tant in endu­rance per­for­mance. Gluconeogenesis or car­bo­hy­drate inges­tion main­tain glu­cose ­after hepat­ic gly­co­gen deple­tion. Lactate may ­also ­serve as a glu­co­ne­o­gen­ic pre­cur­sor as ­well as a ­blood buf­fer.
Methods. To deter­mine if an 8% car­bo­hy­drate (CHO) ­sports ­drink ­with and with­out a 2% lac­tate (L) solu­tion ­increased endu­rance per­for­mance, ­peak pow­er, and ­delayed ­blood aci­do­sis, sev­en ­trained ­cyclists par­tic­i­pat­ed in a dou­ble-­blind ran­dom­ized ­study (6 ­males and 1 ­female) per­formed a bicy­cle ­test to deter­mine max V.O2max HR and the HR asso­ciat­ed ­with the ­first res­pir­a­to­ry ­exchange ­ratio (RER) val­ue great­er ­than 1.0 (tar­get HR). Four bicy­cle ­rides to exhaus­tion, sep­ar­at­ed by one ­week, ­were ­done at a con­stant work­load at a HR 10 ­beats ­below ­each ­subject’s tar­get HR. After a 12-­hour ­fast, sub­jects ­received 100 g CHO 2-3 hrs ­before ­each ­test. Mean exer­cise ­heart ­rate was 86-87% max HR. During the ­final 30 s of ­each ­ride the Wingate pow­er ­test was per­formed. Subjects con­sumed ­either (pla­ce­bo, 2% L, 8% CHO or 8% CHO ­plus 2% L) eve­ry 20 min. Blood sam­ples ­were col­lect­ed ­before, eve­ry 30 min dur­ing and imme­di­ate­ly fol­low­ing the ­test.
Results. No sig­nif­i­cant dif­fer­enc­es ­were ­observed in ­total ­time (pla­ce­bo: 95.3±25.8, 2% lac­tate: 95.7±30.0, 8% CHO: 105.2±37.2, 8% CHO+2% lac­tate: 89.0±28.1 min) or ­peak pow­er (pla­ce­bo: 798.2±241.1, 2% L: 750.1±279.2, 8% CHO: 789.4±353.5, 8% CHO+2% L: 716.3±331.3 Watts) ­among ­drinks. There ­were no dif­fer­enc­es in insu­lin, glu­cose, pH and HCO3- ­after the pow­er ­tests ­among the ­drinks.
Conclusion. Exercise per­for­mance is unaf­fect­ed by ­oral sup­ple­men­ta­tion ­with lac­tate.

language: English


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