We measured maximal O2 uptake (V̇O(2 max)) during stationary cycling in 40 pregnant women [aged 29.2 ± 3.9 (SD) yr, gestational age 25.9 ± 3.3 wk]. Data from 30 of these women were used to develop an equation to predict the percent V̇O(2 max) from submaximal heart rates. This equation and the submaximal V̇O2 were used to predict V̇O(2 max) in the remaining 10 women. The accuracy of V̇O(2 max) values estimated by this procedure was compared with values predicted by two popular methods: the Astrand nomogram and the V̇O2 vs. heart rate (V̇O2-HR) curve. V̇O(2 max) values estimated by the derived equation method in the 10 validation subjects were only 3.7 ± 12.2% higher than actual values (P > 0.05). The Astrand method overestimated V̇O(2 max) by 9.0 ± 19.4% (P > 0.05), whereas the V̇O2-HR curve method underestimated V̇O(2 max) by only 1.6 ± 10.3% in the same 10 subjects (P > 0.05). Both the Astrand and the V̇O2-HR curve methods correlated well with the actual values when all 40 subjects were considered (r = 0.77 and 0.85, respectively), but the V̇O2-HR curve method had a lower SE of prediction than the Astrand method (8.7 vs. 10.4%). In a comparison group of 10 nonpregnant sedentary women (29.9 ± 4.5 yr), an equation relating %V̇O(2 max) to HR nearly identical to that obtained in the pregnant women was found, suggesting that pregnancy does not alter this relationship. We conclude that extrapolating the V̇O2-HR curve to an estimated maximal HR is the most accurate method of predicing V̇O2(max) in pregnant women.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Applied Physiology|
|State||Published - 1988|
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation