VAN DUSER, B. L. and P. B. RAVEN. The effects of oral smokeless tobacco on the cardiorespiratory response to exercise. Med. Sci. Sports Exerc., Vol. 24, No. 3, pp. 389-395, 1992. The purpose of this investigation was to determine the effects of oral smokeless tobacco (OST) usage on oxygen uptake ([latin capital V with dot above]O2), cardiac output ([Latin capital letter Q with dot above]c), stroke volume (SV), heart rate (HR), and plasma lactate concentration (Lc) during rest and exercise. Fifteen asymptomatic subjects were recruited from 18 to 33-yr-old male users of OST. Comparisons of the responses of [latin capital V with dot above]O2, [Latin capital letter Q with dot above]c, SV, HR, and Lc were made between 2.5-g OST and placebo experimental conditions during rest and at 60% and 85% maximal [latin capital V with dot above]O2 treadmill exercise. Plasma nicotine concentrations (Nc) were determined by radioimmunoassay. There were significant increases in HR and Lc and a decrease in SV during rest and at 60% and 85% maximal exercise (P < 0.05). Furthermore, there were no significant differences in maximal HR, Lc, and [latin capital V with dot above]O2 (P > 0.05). In conclusion, these data indicate that the increased Nc incurred by OST usage increases anaerobic energy production and produces an increased tachycardiac response to a given relative submaximal workload.
(C)1992The American College of Sports Medicine