The effect of Hypothyrodism on the heart rate response during submaximal exercise on cycle ergometer. (2010) Biology of Exercise vol (15) p:103-110.
The effect of Hypothyrodism on the heart rate response during submaximal exercise on cycle ergometer. (2010) Biology of Exercise vol (15) p:103-110.
The aim of the present study was to evaluate the heart rate response during constant-load submaximal exercise in patient with hypothyroidism treated with medication. The present study was conducted on 5 women with known hypothyroidism controlled with medication (HYPO group) and 5 women with normal thyroid function (CONTROL group). All subjects were college students, physically active and aged between 19 and 28 years. Exercise testing on Monark cycle ergometer was performed for 6 minutes with constant load of 50 watts at 50 RPM (repetitions per min). Although the results from the present study revealed no statistical significant difference in the response of the heart rate at any point of time between the two groups, the repeated measures one-way ANOVA for the CONTROL group showed there was significant difference (p=0.002) only between HRrest vs HR6-min, while for the HYPO group there were significant differences between the HRrest, HR1-min, HR2-min vs the HR6-min (p=0.000, p=0.007, and p=0.003 respectively). Thus, revealed the slower kinetics of heart rate in HYPO group compared to the heart rate of CONTROL group (steady-state HR for HYPO group was reached at the 3rd minute vs for the CONTROL group was reached from the 1st minute of exercise during constant-load submaximal exercise on cycle ergometer). This study demonstrates that women with hypothyroidism had slower kinetics in the increase of heart rate during submaximal exercise with constant-load and suggests that although the HYPO group was under medication, the impairment on the cardiovascular system by the disease of hypothyroidism still exists.
