Prediction of VO2max during cycle exercise in pregnant women

Abstract

We measured maximal O2 uptake (VO2max) 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 VO2max from submaximal heart rates. This equation and the submaximal VO2 were used to predict VO2max in the remaining 10 women. The accuracy of VO2max values estimated by this procedure was compared with values predicted by two popular methods: the Astrand nomogram and the VO2 vs. heart rate (VO2-HR) curve. VO2max values estimated by the derived equation method in the 10 validation subjects were only 3.7 +/- 12.2% higher than actual values (P greater than 0.05). The Astrand method overestimated VO2max by 9.0 +/- 19.4% (P greater than 0.05), whereas the VO2-HR curve method underestimated VO2max by only 1.6 +/- 10.3% in the same 10 subjects (P greater than 0.05). Both the Astrand and the VO2-HR curve methods correlated well with the actual values when all 40 subjects were considered (r = 0.77 and 0.85, respectively), but the VO2-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 %VO2max 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 VO2-HR curve to an estimated maximal HR is the most accurate method of predicting VO2max in pregnant women.

Moderate impact of full‐term pregnancy on estimated peak oxygen uptake, physical activity and perceived health

“…The strengths of the study were the prospective approach, use of validated methods and a more than 10‐fold higher number of women included as compared with previous experimental studies of oxygen uptake in pregnancy (22–24). The number of non‐participants was a limitation.…”

“…In early pregnancy, resting heart rate increases more than oxygen consumption followed by further increase as pregnancy advances to about 15–20 beats/minute over non‐pregnant values. Also, maximum heart rate is attenuated during maximal exercise testing (12,22,25,26). These changes might affect the heart rate based method of estimation of , such as by the åstrand nomogram used in this study.…”

Maternal inflammation during late pregnancy is lower in physically active compared with inactive obese women

“…Cardiorespiratory fitness levels were assessed using the YMCA submaximal multistage cycle ergometer test as previously described (Beekley et al 2004) using a Lode Corvial Recumbent cycle ergometer (Lode B.V., The Netherlands). Results were used to predict participant’s VO 2peak via the VO 2 -Heart Rate extraction method, which is considered more accurate for pregnant women than the Astrand-Ryhming test (Sady et al 1988; Thorell and Kristiansson 2012; Thorell et al 2015). A three-lead electrocardiogram was applied to monitor heart rate throughout the duration of the exercise test.…”

Pregnancy related back pain, is it related to aerobic fitness? A longitudinal cohort study

“…Prospective research on healthy subjects has not identified low activity or fitness levels as significant risk factors for developing chronic low back pain [12]. Physical fitness levels can be assessed by submaximal incremental exercise methods, such as cycle ergometer test, which have shown good agreement with oxygen uptake measured with gas analyses as gold standard [13-15]. …”