EXPLORING THE EFFECTS OF VIGOROUS INTERVAL TRAINING, MODERATE RESISTANCE TRAINING AND PILATES ON ARTERIAL STIFFNESS AND BLOOD PRESSURE DURING PREGNANCY: A RANDOMISED CROSS-OVER TRIAL

Abstract

INTRODUCTION Regular moderate intensity exercise throughout pregnancy provides significant benefits to both maternal and foetal cardiovascular health outcomes. Current exercise guidelines recommend a combination of moderate intensity aerobic and resistance training (RT). However, there is limited research exploring the cardiovascular effects of higher intensities (vigorous/high) in comparison to common pregnancy exercise modalities such as RT and Pilates (PIL). AIM: To investigate the acute effects of three modes of exercise (resistance, vigorous aerobic intervals and Pilates) during trimester two (T2) and three (T3) of pregnancy on measures of arterial stiffness (pulse wave velocity [PWV]) and blood pressure (BP). METHODS Eleven women with uncomplicated pregnancies (age 32 ± 3 years, pre-pregnancy BMI 23.9 ± 3.5 kg/m2) completed testing in T2 (average 20 ± 1.6 weeks gestation) and T3 (average 29 ± 2.5 weeks gestation). Participants performed one each of vigorous intensity interval training (VIIT) (∼33 min), resistance training (RT) (∼35 min) and Pilates (PIL) (∼35 min) in T2 and T3 in randomised order approximately 1 week apart each trimester. Resting outcome measures of PWV, BP and foetal heart rate (FHR) were obtained following 5 minutes of rest and again immediately and 10 minutes post exercise session. BP, maternal heart rate (MHR), and rating of perceived exertion (RPE) were monitored throughout. RESULTS There was no difference in the acute PWV response to each type of exercise across the trimesters (1 min VIIT: T2 = 5.53 ± 0.85m/s, T3 = 5.26 ± 0.67m/s, 95%CI[-1.36-0.67]; RT: T2 = 5.4 ± 0.80m/s, T3 = 5.48 ± 0.56m/s, 95%CI[-0.88-1.10]; PIL: T2 = 5.44 ± 0.68m/s, T3 = 5.44 ± 0.68m/s, 95%CI[-0.93-1.01]). There was no significant difference in the acute response in SBP to VIIT (T2 = 116 ± 12.1mmHg, T3 = 122 ± 7.2mmHg, 95%CI[-0.42 - 1.65]. SBP was significantly higher in T3 than T2 1 minute following PIL (T2 = 110 ± 5.8mmHg, T3 = 121 ± 11.7mmHg, 95%CI[0.04-2.1]) and 10 minutes following RT (T2 = 105 ± 10.1mmHg, T3 = 116 ± 5.0mmHg, 95%CI[0.27 - 2.46]. CONCLUSION VIIT, RT and PIL appear to elicit similar post-exercise haemodynamic and arterial stiffness responses in both the mother and foetus. As such, VIIT may be a suitable addition to standard moderate intensity and RT prescription during an uncomplicated pregnancy.