Exercise

The bow was invented in the late Paleolithic Era, about 10,000 to 9,000 BCE.

Apex - about 50,000

Building muscle tissue through anaerobic exercise is the best way to ensure a high calorie-burning metabolic rate.

The Great Depression of the 1930's ended when the U.S entered World War II. Entering war helps get out of an economic depression because it takes men out of the work force and puts them in the military, causing the rest of the U.S to enter the job market. Then they mass produce many products which causes the economy to boom.

Thinning of the blood

Hiking

Uphill and downhill hiking use different sets of muscles. Hiking uses your leg and bike muscles, due to the climbing that is involved.

Talk to a coach

Steel ball bearings.

wrestling
the marathon, and wrestling. Both (or variations of both) were played at the ancient olympics.

It is the only raquet and ball sport that is known to many people across the world, and the only ball and raquet sport aired on popular TV.

They tended to be fitter and leaner

The X Games have gained world wide television coverage and popularity - APEX

Can be done anywhere outside

They are safe substitutes for