<span>Proteins are the main building blocks for tissues including muscle, hair, nails, skin, eyes, internal organs, nerves, ligaments, tendons, cartilage and membranes. They are also the building blocks of cells, cellular membranes, organelles--all the way to the level of DNA and genes.</span>
Since someone would be performing wind sprint activities, it is guaranteed when performing any activity is to get better overtime so I would say to "work above your target heart rate"
