题目内容：

Whenever I hear a recording of John Denver singing “Sunshine on My Shoulders,” I find myself smiling, drawn to a love of the sun and outdoors I’ve had for decades as a Michigan native. Walking barefoot to the lake, playing shiftless in the sunlight, and breathing fresh air feel good. 1.

Studies have found higher rates of high blood pressure among people with the lowest sun exposure. One reason may be due to nitric oxide, a gas whose production is stimulated when your skin is exposed to the sun’s rays. 2. Vitamin D, which sunlight helps your body produce, is also linked to better heart health. So walk outdoors for 15 to 30 minutes daily.

3.Research on 280 volunteers there found that people had a reduced heart rate, and lower blood pressure when they walked through a forest than when they spent time in an urban area.

One of the consequences of modem society is that rarely is our body in direct contact with the ground. The earth has an electrical current. 4. Although “earthing” or “grounding” is considered alternative by mainstream medicine, research shows that the practice seems to be able to reduce heart disease risk. So, walk around barefoot whenever possible, let your backyard grass tickle your feet, and dig your toes into sandy beaches.

5. A 2011 British review of 11 studies found that people who exercised outside generally reported more energy and less anger, tension, and depression—all factors contributing to heart attack—than those who worked out indoors.

A. Exercising indoors is another option.

B. It reduces both heart attack and stroke risks.

C. As a doctor, I can tell you they are also very good for your heart.

D. Direct contact with it may be a stabilizing force for good health.

E. In Japan, walking through forests for healing has become a popular practice.

F. Exercising outdoors may be more beneficial than working out indoors.

G. You’ll get greater health benefits exercising where it’s green.