New York: Exposure to sunlight may be a factor in lowering blood pressure. Studies have shown that in people with mild hypertension, blood pressure tends to be lower in the summer than in the winter, and that both average blood pressure and the incidence of cardiovascular disease tend to increase with distance from the equator.
Researchers exposed 24 healthy volunteers to ultraviolet A radiation for 30 minutes with an intensity comparable to noon on a sunny day in Southern Europe. The exposure caused a small but significant drop in blood pressure compared with when the same people were exposed to sham UVA radiation. Blood tests showed that UVA exposure caused a release of nitric oxide from the skin into the bloodstream. Nitric oxide causes arteries to dilate, and this, scientists believe, accounts for the effect.
How to reduce knee pain while climbing
New York: Most people with knee arthritis — meaning some degeneration of the cushioning cartilage in the joint — experience pain when they go down stairs, even if their arthritis is otherwise mild, said Dr. Kevin J. Bozic, an orthopaedic surgeon at the University of California, San Francisco. More so than climbing stairs, descending them places great force on the knee and, in particular, the patello-femoral joint, the portion of the knee beneath the kneecap, he said.
So to strengthen your quadriceps, try straight leg raises, Dr. Bozic said. Simply lie on your back with one leg bent. Lift the other leg, straightened, at least six inches off the ground; tighten the thigh muscles and hold for a few seconds. Lower and repeat several times. Then do the same exercise with the other leg. Your physician or an athletic trainer can suggest other safe exercises that target those muscles.