A limited body of knowledge exists concerning exercise tolerance in treated patients with hypothyroidism, and there is an insufficient amount of quantitative studies on the effects of a physical training program. To enhance exercise and sports participation for this specific group, more research in this forgotten area is warranted.

Awareness of physical activity (PA) constraints in patients with primary hypothyroidism on thyroid hormone replacement therapy (THR) is important. Hence, this cross-sectional matched case-control study aimed to determine PA and sports participation (SP) in patients with hypothyroidism on THR in comparison to control subjects. Accordingly, survey questions were selected from the National Survey on Injuries and Physical Activity in the Netherlands (IPAN), supplemented with questions related to selfreported clinical characteristics and exercise-related constraints (ERC) of patients. In total, 1,724 female patients (mean age 53.0 years ±11.6) and 1,802 controls (mean age 52.6 ± 13.2) were included. Compared to controls, patients were less likely to comply with the moderate-intensity PA guideline (OR 0.70; 95% CI: 0.611-0.803), although patients were more actively participating in sports (OR 1.40; 95% CI: 1.156-1.706). Two-thirds of patients reported that hypothyroidism was limiting their PA performance. These limitations were more pronounced in patients with autoimmune thyroiditis (AIT) than in patients with hypothyroidism from other aetiology (OR 1.93; 95% CI: 1.518-2.457), representing disease-specific exercise intolerance. In order to establish effective intervention programmes to encourage regular PA in hypothyroid patients on THR with exercise intolerance, further research is warranted to better understand PA barriers.

Background: The purpose of this study was to analyze factors associated with physical activity (PA) and to identify perceived barriers and benefits of PA among patients with hypothyroidism on thyroid hormone therapy. Methods: This survey-based cross-sectional study was conducted among members of the Dutch thyroid patient organization. Self-reported data on respondents’ PA levels and demographic, clinical, and physical health variables were collected. Moreover, perceived barriers and benefits to PA were identified. Respondents were categorized as physically active when meeting the recommended Dutch PA guidelines and physically inactive otherwise. To compare physically active and inactive respondents, potential confounders were entered into univariate analyses. Factors showing significant correlations (P < .20) were added to a multivariate model to determine the associated factors of PA. Results: About 1724 female respondents (mean age 53.0 [11.6] y) were included; 16.1% reported meeting the PA recommendations. Multivariate analysis showed that factors associated with PA included levothyroxine/liothyronine therapy, comorbidities, self-perceived physical fitness, and diminished physical endurance. Overall, physically related barriers to PA were rated highest. Conclusions: The vast majority of treated hypothyroid respondents are physically inactive and experience long-term exercise intolerance. Considering the health implications of physical inactivity, promotion of regular PA is of key importance in this population.