Author(s): COTE, A., RICHARD, N., FENUTA, A.M., Institution: TRINITY WESTERN UNIVERSITY, Country: CANADA, Abstract-ID: 1872

INTRODUCTION:
Hypertensive disorders of pregnancy (HDP; e.g. preeclampsia, gestational hypertension) affect up to 15% of pregnancies worldwide. Substantial evidence links HDP to increased future cardiovascular risk, with cardiac dysfunction shown to persist for more than a decade postpartum. Exercise has been shown to improve cardiovascular health outcomes for individuals with adverse pregnancy outcomes, including HDP, although many report time as a major barrier to exercise. Recently, we showed that 6 weeks of sprint-interval training (SIT) was effective for increasing fitness and was well tolerated (high compliance; no adverse events) by active females without HDP in the early postpartum period. However, there are no reports of a postpartum SIT intervention for individuals with HDP. As such, we sought to explore the feasibility of a 12-week SIT intervention and changes in aerobic capacity and cardiovascular function following HDP.
METHODS:
A 35-year-old recreationally active female who had gestational hypertension (i.e., blood pressure >140/90) visited the lab on three occasions: 6-weeks postpartum (pre), following 6 (post-1) and 12 weeks of SIT (post-2). At each visit, resting cardiovascular function (blood pressure, ECG, echocardiogram) and aerobic capacity were assessed. An incremental cycling protocol was used to assess VO2max and peak power output (PP). Training was designed as a progressive, home-based SIT cycling program at 130% PP (3/wk, 4-8 30-second all-out sprints, 1:2 work-to-rest ratio; session length 20-30 minutes). Training occurred on a smart-trainer, and the virtual Zwift platform was used to track workouts. The participant also recorded heart rate, RPE and comments for each session.
RESULTS:
Blood pressure was normal throughout the study (pre: 99/58, post-1: 108/65, post-2: 102/60 mm Hg), and she was not taking any medication. Body mass decreased by ~1 kg at post-1 and post-2. After 6 weeks of SIT, VO2max and PP both increased by 20% (VO2max: pre: 32 vs. post-1: 37.4 ml/kg/min). Increases were also seen for left ventricular mass (66.9 vs. 70.4 g/m2), resting stroke volume (71 vs. 82 mL) and cardiac output (4.5 vs. 4.7 L/min). At post-2, VO2max and PP remained the same as post-1. Resting myocardial function using global longitudinal strain was similar at each time point (-20.8, -19.8, -19.5%). The participant reported enjoying the workouts and that the short duration of each session made 100% compliance possible. She reported no issues with breastfeeding or onset of injuries/adverse events.
CONCLUSION:
This study illustrates the feasibility of a 12-week home-based SIT cycling intervention in early postpartum for an active individual following HDP. While compliance was high throughout, VO2max, PP, and cardiovascular function improved predominantly in the first 6 weeks. This pilot will inform a clinical trial designed to assess the effects of high-intensity, short-duration exercise on cardiovascular health and fitness after HDP.