Radiographic evidence of pulmonary edema during high-intensity interval training in women

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Abstract

The purpose was to determine if an intense interval training session could produce transient pulmonary edema in women. Fourteen females [(27 ± 4 years; body mass index of 21.6 ± 1.5 kg/m2); maximal oxygen consumption = 3.12 ± 0.42 L/min] performed three sets of 5 min sea-level cycling exercise with 10-min recovery between each set. Average oxygen consumption at minute 5 of each set was 96 ± 5% of maximum and arterial plasma lactate concentration at minute 5 of each set was 16.0 ± 3.3 mmol/L. Chest radiographs were obtained before and 33.2 ± 6.1 min after exercise. Four different chest radiologists independently reviewed the radiographs for edema, and scored seven validated radiographic characteristics on a three-point scale (0–2). The overall edema score increased from 1.3 ± 1.6 before exercise to 1.9 ± 2.0 after exercise [P < 0.05; Δ = +0.7 ± 1.8, 95% CI, 0.2 to +1.1]. This study shows that an intense interval training session can cause mild, detectable pulmonary edema in some women.

Introduction

The question of whether pulmonary edema can occur in humans from heavy endurance exercise remains controversial. A decrease in lung diffusion capacity for carbon monoxide (DLCO) post-exercise along with simultaneous increase in lung density from computed tomography (CT) measurements points to a mild acute pulmonary edema (Caillaud et al., 1995). Specifically, a decrease in lung diffusion capacity for nitric oxide (DLNO) indicates that alveolar capillary membrane diffusional conductance – and thus the blood–gas barrier – can be structurally/functionally impaired post-exercise (Zavorsky and Lands, 2005). However, other studies using CT (Manier et al., 1999), and visual inspection of chest radiographs (Gallagher et al., 1988) fail to show any significant increases in pulmonary extravascular lung water from exercise. Indeed, the differences in intensity and duration of the exercise protocol may be partly responsible for the varied findings. For example, there is radiographic evidence that cycling for more than 3 h at altitude or running for 9 h can result in pulmonary edema (Anholm et al., 1999, McKechnie et al., 1979), while a 20 min ramped cycling protocol or 2 h of running at 75% maximal oxygen consumption (V˙O2max) does not (Gallagher et al., 1988, Manier et al., 1999). Furthermore, most of the radiographic, CT, and magnetic resonance imaging (MRI) studies have focused exercise protocols using only male subjects (Caillaud et al., 1995, Gallagher et al., 1988, Manier et al., 1999, McKechnie et al., 1979, McKenzie et al., 2005). It would be interesting to examine the effects of intense exercise on the development of pulmonary edema in women because relative to body size, women have a lower DLCO, smaller airway diameter, and smaller lung volumes than men (Hopkins and Harms, 2004). Therefore, the lung may be more prone to imposed stresses of exercise in fit women compared to fit men. Therefore, the aim of this study was to determine through visual inspection of chest radiographs if pulmonary edema can occur from an intense interval training session at sea level in women cyclists. Our hypothesis was that mild acute pulmonary edema would occur in women from interval training due to the relatively smaller lungs in women compared to men, even when normalized to body size.

Section snippets

Subjects

Fourteen female subjects (27 ± 4 years; body mass index of 21.6 ± 1.5 kg/m2; maximal oxygen consumption = 3.12 ± 0.42 L/min or 50.2 ± 5.8 mL/kg/min) were recruited to participate on two different days. All females were nonsmokers and were either competitive (4) or recreational (10) cyclists. These females had been regularly training 5× per week for at least the previous 6 months. Subjects gave informed consent and completed a Physical Activity Readiness Questionnaire (PAR-Q). This study was approved by the

Results

All subjects reported fatigue by the end of the 3× 5 min strenuous interval training session. All subjects completed the workout. The V˙O2 averaged over minutes 1–5 of all three sets was 91 ± 4% of maximum (Table 1). This is much higher than average workload sustained for all three sets. We initially thought that the cyclists could sustain 90% of the maximum workload achieved for their V˙O2max test for all three sets, but in fact, we had to reduce the workload during each set so that the subject

Discussion

To our knowledge, this is the first study that examines whether pulmonary edema occurs in fit women from an interval training session. We have shown that an interval training session consisting of a total of 15 min of strenuous exercise can cause mild acute clinically significant pulmonary edema in women which was not related to performance, body size or lung volume. Sixty-four percent of our women studied showed signs of pulmonary edema, which is similar to the 70% reported in other cyclists (

Acknowledgements

The authors would like to thank the chest radiologists Genèvieve Belley, Marie-Lucie Doyon, Joseph Casullo, and Robert Hidvegi for their interpretation of the radiographs. The authors would also like to thank Juan Manuel Murias for his help in this study and the x-ray technicians John Douglas and Claire Duquette.

References (27)

  • B. Hanel et al.

    Maximal rowing has an acute effect on the blood–gas barrier in elite athletes

    J. Appl. Physiol.

    (2003)
  • J.L. Hankinson et al.

    Spirometric reference values from a sample of the general US population

    Am. J. Respir. Crit. Care Med.

    (1999)
  • S.R. Hopkins et al.

    Gender and pulmonary gas exchange during exercise

    Exerc. Sport Sci. Rev.

    (2004)
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