The first kind is used for endurance activities, the second is for strength activities. (fitnessandpower.com)
Originally invented by Russians for strength and flexibility, now kettlebells are used for a wide range of strength activities, from Muscle and Strength Training to losing Weight. (exercisegoals.com)
A recent study at the Johns Hopkins Center on Aging and Health found a clear link between carotenoids, such as astaxanthin, and improved muscle strength activity levels. (liveinthenow.com)