Compression clothing has many functions, but one goal: to improve athletic performance. Compression sleeves are designed to aid blood flow, reduce lactate build up and to stop muscle oscillation and vibration that would otherwise lead to premature fatigue. Calf sleeves can also reduce the shock of impact over long distance and uneven terrain meaning your legs can stay fresher for longer and recovery time will be reduced. Arm sleeves both reduce shock and also help in postural maintenance, which is especially crucial in 'tuck' positions for time-trial or triathalon races.