Paul Fadel, associate professor of medical pharmacology and physiology, and John Thyfault, associate professor of nutrition and exercise physiology, also found that the vascular dysfunction induced by five days of inactivity requires more than one day of returning to physical activity and taking at least 10,000 steps a day to improve.
"We know the negative consequences from not engaging in physical activity can be reversed," said Fadel. "There is much data to indicate that at any stage of a disease, and at any time in your life, you can get active and prolong your life.
"However, we found that skipping just five days of physical activity causes damage to blood vessels in the legs that can take a prolonged period of time to repair," said Fadel.
The researchers studied the early effects on the body's blood vessels when someone transitions from high daily physical activity - 10,000 or more steps per day - to low daily physical activity, less than 5,000 steps per day. The researchers found going from high to low levels of daily physical activity for just five days decreases the function of the inner lining of the blood vessels in the legs.
"The impairment we saw in just five days was quite striking. It shows just how susceptible the vascular system is to physical inactivity," Fadel said.The research was published in the Journal of Applied Physiology.