Durability is the toughness, strength, and soundness of your joints. The best way to become a more durable rider is to ride more! As you are strengthening your knees and ankles give them an occasional break by riding at a walk with your feet out of the stirrups or get off and lead.
Glucosamine, Chondroitin, MSM – they’re not just for your horse!
Vet supply and drug store shelves are packed with glucosamine hydrochloride and chondroitin sulfate supplements which claim the ability to repair joint cartilage and/or slow degeneration. MSM (methylsulfonylmethane) is marketed as an anti-inflammatory especially helpful in pain relief of soft tissue injury. While studies on the effectiveness of these products have various conclusions, their margin of safety is high. And first-hand testimonies abound from folks with previously frozen or creaky joints who can now use their arms and knees in a full range of motion. Such nutraceuticals may be well worth a personal look and test. (Note that some folks have an allergy to shark cartilage which is the source of some MSM.)