"To be prudent, I'd recommend cutting exercise duration and intensity when symptoms are present, " says Woods.

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Although several studies have looked at exercise for diabetes, the current investigation is unique for its long duration, as well as the fact that it included an ethnically diverse group of patients, says Ronald J.

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In heart disease studies, for example, subjective outcomes might include the duration and severity of chest pain, shortness of breath, or ability to exercise without pain.

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