Physiological Characteristics Of Elite Irish Junior Middle and Long Distance Runners

Abstract

PURPOSE To characterize and compare the physiological profiles of elite male and female junior middle distance (MD) and long distance (LD) runners. METHODS Maximal oxygen consumption (VO2max) and running economy (RE) were determined in 18 male (18.0 ± 1.6 y) and 14 female (17.1 ± 1.4 y) elite Irish junior MD and LD runners. A series of 6–9 submaximal runs (3 min duration with 1 min recovery) were performed on a treadmill with a 1% inclination, to determine RE and blood lactate levels. The treadmill velocity was increased by 0.5 miles.hr−1 at the beginning of each exercise stage. Following a 1-h recovery period, subjects performed a maximal treadmill test (ramp protocol) to determine VO2max. Expired oxygen, CO2, ventilatory volume (Ve) heart rate (HR) and rating or perceived exertion (RPE) were measured throughout each test. Velocity at VO2max (vVO2max) was calculated by simple linear regression using VO2max and RE. Blood samples were taken during the recovery period following each submaximal run. This was used to determine lactate threshold (LT,) and the onset of blood lactate accumulation at 2 mmol.l−1 (OBLA), the %VO2 at LT (%VO2LT), the %HR at LT (%HRLT), the velocity at LT (Vel-LT). The ventilatory threshold (VT) was determined using the Vslope and Vebreak methods. RESULTS VO2max and vVO2max was higher (p<0.01) in males than females. RE expressed as ml.kg−I·min−I and ml.kg−I.km−I was similar in males and females at 7.0, 7.5, 8.0, 8.5 and 9.0 miles.hr−I and at 60%, 70% and 80%VO2. The %VO2 was lower (P <0.01) in males than females at each treadmill velocity. Males and females were most economical when running at 9.0 miles.hr−I (189.2 ml.kg−I.km−I) and 8.0 miles.hr−I (189.3 ml.kg−I.km−I) respectively. The VO2LT, VO2OBLA, and the VO2 at VT (VO2VT) were greater (p<0.05) in males than females. The Vel-LT, Vel-OBLA, and the treadmill velocity at VT (Vel-VT) were greater (p<0.05) in males than females. The %VO2VT and %HR at the ventilatory threshold (%HRVT) were similar in men and women. In the male athletes, the %VO2LT, %HRLT, and the Vel-LT were lower (P <0.01) than the %VO2VT, %HRVT and the Vel-VT. Females had a lower (P <0.05) %VO2 at LT than at VT. CONCLUSIONS Elite male junior MD and LD runners have a higher VO2max, and greater vVO2max than their female counterparts. The most economical running speed for elite junior female and male MD and LD runners is 8.0 miles.hr−I and 9.0 miles.hr−I respectively. The VO2LT is higher in males that females. In contrast, the %VO2LT was higher in female than male athletes.