Exercise-induced arterial hypoxemia is not different during cycling and running in triathletes
- Authors: Laursen, Paul , Rhodes, Edward , Langill, Robert , Taunton, Jack , McKenzie, Donald
- Date: 2005
- Type: Text , Journal article
- Relation: Scandinavian Journal of Medicine and Science in Sports Vol. 15, no. 2 (2005), p. 113-117
- Full Text: false
- Reviewed:
- Description: This study examined the effect of running and cycling on exercise-induced arterial hypoxemia (EIAH) in individuals well trained in each modality. Thirteen male triathletes (x̄ ± SD: age = 36 ± 5 years, mass = 69 ± 8 kg, body fat = 12 ± 1%) performed progressive exercise to exhaustion during cycle ergometry and treadmill running. Gas exchange was determined, while oxyhemoglobin saturation (SaO2) was measured with an ear oximeter. At maximal exercise, the respiratory exchange ratio (1.15 ± 0.06 vs. 1.10 ± 0.05) and the ventilatory equivalent for oxygen uptake (37.6 ± 3.8 vs. 34.2 ± 2.7) were greater during cycling vs. running (P < 0.05). However, there were no differences at maximal exercise in oxygen uptake (64.4 ± 3.2 vs. 67.0 ± 4.6 mL kg-1 min-1), SaO2 (93.4 ± 2.8% vs. 92.6 ± 2.2%), or the ventilatory equivalent for carbon dioxide (V̇E/ V̇CO2; 33.1 ± 3.1 vs. 31.0 ± 3.1), during cycling vs. running, respectively. During submaximal exercise, the V̇E/ V̇CO2 was less for cycling (26.0 ± 1.0) compared with running (29.1 ± 0.4; P < 0.05), but this had no apparent effect on the SaO2 response. In conclusion, EIAH was not significantly different during cycling and running in athletes who were well trained in both exercise modalities. Copyright © Blackwell Munksgaard 2004.
- Description: C1
Relationship between laboratory-measured variables and heart rate during an ultra-endurance triathlon
- Authors: Laursen, Paul , Knez, Wade , Shing, Cecilia , Langill, Robert , Rhodes, Edward , Jenkins, David
- Date: 2005
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 23, no. 10 (2005), p. 1111-1120
- Full Text: false
- Reviewed:
- Description: The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean ± s: age 35 ± 6 years, height 1.77 ± 0.05 m, mass 74.0 ± 6.9 kg, V̇O2peak = 4.75 ± 0.42 l · min-1) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (V̇O 2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 ± 9 and 143 ± 13 beats · min-1 respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 ± 13 and 165 ± 14 beats · min-1 respectively) and heart rate deflection points (170 ± 13 and 179 ± 9 beats · min-1 respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 ± 12 and 148 ± 15 beats · min-1 respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold. © 2005 Taylor & Francis.
- Description: C1