Compulsive Exercise Predicts Poorer Mental Health in Pregnancy: A One-Month Longitudinal Investigation

Abstract

Introduction: While exercise is often recommended as beneficial for mental health, its role during pregnancy is less clear. The aim of this study was to examine the role of exercise behaviour and compulsive exercise attitudes in relation to perinatal anxiety and depression.

Method: Pregnant women answered an online battery of psychometric questionnaires assessing perinatal depression (Edinburgh Postnatal Depression Scale, EPDS), anxiety (Perinatal Anxiety Screening Scale, PASS), compulsive exercise (Compulsive Exercise Test, CET), social support (Multidimensional Scale of Perceived Social Support, MSPSS), as well as reporting exercise frequency and intensity, sleep, stressors and pregnancy. Depression screening was repeated one month later.

Results: Eighty-eight pregnant women participated, with a mean age of 31.4 years (SD = 4.50). All identified as women, 50% had one child, 23% none and the remainder two or more. Sixty-two percent were NZ European, 13% Māori and 3% of Pacific ethnicity. Median baseline gestation was 24 weeks (SE = 1.1), with 9% less than 10 weeks pregnant, 29% between 11-20 weeks, 33% between 21-30 weeks and 28% over 31 weeks gestation. A large number of participants reported substantial perinatal mental health symptoms. At baseline, 28.1% met clinical criteria for depression (EPDS M=7.93, SD=4.10), increasing to 37.3% at one month; 20.7% met clinical anxiety thresholds (PASS M=17.99, SD=12.20). Both were predicted by poor sleep, stress, and low social support, though exercise was not significant in these regression models. Most participants (70%) reduced their exercise during pregnancy and reported low-moderate weekly exercise. Exercise frequency showed trend-level associations with baseline depression and anxiety (η²=.06–.07), but not follow-up depression. Compulsive exercise was uncommon (4.5%), while 85.2% reported high social support. Most participants experienced ≥1 stressor (59%) and nearly half reported sleep problems (47%). Multivariate models indicated that lower social support and greater stress predicted anxiety (R²=.42), while baseline depression was associated with lower social support and higher compulsive exercise attitudes (R²=.35). Depression at one month was predicted solely by baseline depression and anxiety (R²=.47). Compulsive exercise motivations were associated both with more high-intensity exercise during pregnancy, and with depressive symptoms. A focus on weight control was associated with more high-intensity exercise, and avoidance and rule-driven exercise attitudes predicted higher depression. Those in the highest-range exercise group reported the highest depressive symptoms, and the lowest group had higher anxiety scores. Moderate exercise was not associated with either depression or anxiety.

Conclusions: During pregnancy, mental health appeared more closely tied to compulsive exercise motivations than to exercise behaviour. While moderate exercise would seem to be linked with positive mental health, the reasons behind exercise are important considerations. These pilot findings support holistic perinatal care approaches, including emotional support, lifestyle, and screening for maladaptive exercise attitudes.