When P and S waves hit the surface they transform into surface waves. P and S waves are signatures of fracture rock or earthquake. When a fracture occurs it sends energy out i â¦ n all directions. P, or primary wave is the initial large shock of the earthquake. This travels through anything.
Weekly Cardio Minimum. The Centers for Disease Control and Prevention recommend that all adults engage in at least 2 1/2 hours of moderate aerobic activity per week. If you do intense cardio, you can get away with half that time. You may spread your exercise over as many days of the week as you like, as long as each session lasts at least 10 minutes. In addition, the CDC recommends that all adults engage in some physical activity for 30 minutes a day, at least five days a week.
Aerobic Exercise. The CDC suggests that adults get at least two hours and 30 minutes of moderate aerobic activity per week, or one hour and 15 minutes of vigorous exercise per week. This breaks down to about 30 minutes of exercise per day for at least five days per week. While two hours and 30 minutes of exercise may seem like a lot of time, it's fine to break up your physical activity into more manageable chunks of time, such as three sets of 10-minute intervals during the day.