All types of athletes benefit most from interval training.
Used of second-hand items may be demaged making them less effective and putting you at higher risk for injury.
A mental illness such as anorexia.
All of the above
*apex*
Hike
outdoor exercise is cheap!
snorkeling
helps stamina
Water Polo
Hiking
Healthier Skin
(Apex)
risky because you can sick or hurt
All of the above