Your thyroid secretes hormones that play a key role in energy use, protein manufacture and your body's sensitivity to other hormones, including reproductive hormones. Its proper function is essential to your overall health and well-being, so if you have thyroid problems, such as underactive thyroid, or other hormone-related health issues, you may wonder about the effect of exercise on your thyroid. Exercise actually has beneficial effects on your thyroid, though if you have specific health concerns, you should consult your doctor before beginning or changing your exercise routine.
Hormone Levels
A study published in 2005 in the journal "Neuroendocrinology Letters" shows that aerobic exercise has a significant temporary effect on your body's hormone levels, including the thyroid. Despite the increase in levels, there is no evidence that exercise causes hyperthyroidism. Therefore, exercise alone won't put you at risk of an overactive thyroid. The mechanism for this is not completely understood, but researchers think it is due to specific individual adaptations. This also means that exercise alone will not reverse an underactive thyroid, which requires medical treatment.
Use
While exercise increases the overall level of hormones, it also increases the use of a specific thyroid hormone, called thyroxine. According to "Sports Nutrition: Vitamins and Trace Elements," studies show that athletes can use up nearly twice as much thyroxine as sedentary subjects. This mimics the rate of use seen in hyperthyroidism, but there are no reports to show that athletes suffer from hyperthyroidism as a result. This appears to be because the thyroid-secreting hormone sends the body signals to compensate for the increased use during exercise.
Oxygen Uptake
The book "Adaptive Effects of Hormones in Exercise" notes that the thyroid plays a role in oxygen uptake, thanks to its regulatory effect on other hormones. In studies, adrenaline and cortisol were shown to influence the uptake of oxygen, and also the development of lactic acid -- the substance that causes the burning, tired sensation in your muscles during heavy exercise. Regular exercise appears to enhance the efficiency of the hormonal interactions, helping your body adapt to the demands of heavy training.
Benefits of Exercise
While exercise has a benign effect on normal thyroid function, it has definite benefits for patients who are being treated for a thyroid condition, according to "The Thyroid Solution." Major symptoms of underactive thyroid are fatigue, feelings of weakness, weight-gain and depression. These require medical treatment, but once that treatment is in place, a regular exercise program can combat these symptoms. Recommended exercises include endurance activities such as walking, jogging or swimming, as well as practices such as yoga and tai chi that emphasize total body wellness.
