Ensuring that your bones and cartilage stay healthy is extremely important for anyone embarking on a serious training regime. PhD Nutrition Reinforce - joint health supplement contains glucosamine, chondroitin and hyaluronic acid, along with Vitamin C and MSM to supplement an intense training plan and active lifestyle. Ensuring that your bones and cartilage stay healthy is extremely important for anyone embarking on a serious training regime. PhD Nutrition Reinforce - joint health supplement contains glucosamine, chondroitin and hyaluronic acid, along with Vitamin C and MSM to supplement an intense training plan and active lifestyle.