Blood cells more then any other factor notice water doesn't have any cells in it and it flows freely and quickly.
I believe the answer is a mutation.
Answer:Hiking uphill.
Cycling more than 10 miles per hour or steeply uphill.
Swimming fast or lap swimming.
Dancing, fast dancing, and step aerobics.
Strength training.
Heavy gardening with digging, hoeing
Explanation:
For an activity to be vigorous, you need to work at 70 to 85 percent of your maximum heart rate, according to the American Heart Association. Examples of vigorous exercise include: running. cycling at 10 mph or faster
