I'd recommend beginners sprint on a hill surfaceAlpha Shred of around 30 degrees. This will reduce the risk of injuries and give you better Sprint as fast as you can for up to 15 seconds, then give yourself at least 60 seconds recovery. Repeat for 5 rounds and slowly build up your amount of sprints each week.Be careful not to sprint at full intensity for longer than 15 seconds as hamstring pulls tend to occur after this point due to muscle fatigue.