Endurance training improves heart rate on-kinetics in women with subclinical hypothyroidism: a preliminary study

• Published in: Journal of endocrinological investigation 2023-01, Vol.46 (1), p.51-57
• Main Authors: Almas, S. P., Werneck, F. Z., Coelho, E. F., Teixeira, P. F. S., Vaisman, M.
• Format: Article
• Language: English
• Subjects: Body Mass Index; Endocrinology; Endurance Training; Female; Heart rate; Heart Rate - physiology; Humans; Hypothyroidism; Hypothyroidism - therapy; Infant; Internal Medicine; Kinetics; Medicine; Medicine & Public Health; Metabolic Diseases; Original Article; Physical activity; Physical Endurance - physiology; Physical training; Statistical analysis
• ISSN: 1720-8386; 0391-4097; 1720-8386
• DOI: 10.1007/s40618-022-01882-8

Purpose The aim of the study was to evaluate the effect of endurance training on heart rate (HR) on-kinetics in patients with subclinical hypothyroidism (SH). Methods Eighteen women were randomly assigned to trained group (TG) or control group (CG). Both groups performed three tests at 50 W in a cycle ergometer for 6 min. HR kinetics was obtained during the tests and the mean response time (MRT), which is equivalent to the time taken to reach 63% of the HR at steady state, was extracted. The TG was then submitted to 12 weeks of endurance training (50 min, 3x/week, intensity between 70 and 85% of the maximum HR predicted for the age). Statistical analysis was performed by the mixed analysis of variance. Results At baseline, TG and CG were similar for TSH (7.7 ± 3.1 vs. 6.9 ± 3.3 mUI/L, p  = 0.602, respectively) and FT4 (12.31 ± 1.51 vs. 12.20 ± 1.89 pmol/L, p  = 0.889, respectively). After adjustment for body mass index and age, interactions between moment (baseline or after 12 weeks) and group (trained or control) were only significant for MRT (TG: 39.6 ± 10 to 28.9 ± 8.4 s, CG: 53.6 ± 20.3 to 55 ± 19.7 s, p  = 0.001) and physical activity level (CG: 7.3 ± 0.7 to 8 ± 0.9, CG: 6.8 ± 0.8 in both moments, p  = 0.005). Conclusion The preliminary results suggest that 12 weeks of endurance training improve HR on-kinetics and physical activity level in SH.