Recovery from exercise-induced desaturation in the quadriceps muscles of elite competitive rowers

B. Chance, M. T. Dait, C. Zhang, T. Hamaoka and F. Hagerman Department of Biochemistry and Biophysics, Johnson Research Foundation, University of Pennsylvania, Philadelphia 19104. A simple muscle tissue spectrophotometer is adapted to measure the recovery time (TR) for hemoglobin/myoglobin (Hb/Mb) desaturation in the capillary bed of exercising muscle, termed a deoxygenation meter. The use of the instrument for measuring the extent of deoxygenation is presented, but the use of TR avoids difficulties of quantifying Hb/Mb saturation changes. The TR reflects the balance of oxygen delivery and oxygen demand in the localized muscles of the quadriceps following work near maximum voluntary contraction (MVC) in elite male and female rowers (a total of 22) on two occasions, 1 yr apart. TR ranged from 10 to 80 s and was interpreted as a measure of the time for repayment of oxygen and energy deficits accumulated during intense exercise by tissue respiration under ADP control. The Hb/Mb resaturation times provide a noninvasive localized indication of the degree of O2 delivery stress as evoked by rowing ergometry and may provide directions for localized muscle power output improvement for particular individuals in rowing competitions.