Ankle weights are bands that fasten around the ankles, often with Velcro, that contain a heavy material, such as sand, metal bars or pellets, for the purpose of adding weight to the legs to build strength during exercise. Using ankle weights can increase the effectiveness of workouts by providing additional resistance to the legs.
The main advantage of using ankle weights is that they increase the intensity of exercise involving the legs so that a workout can be shorter in duration and still achieve the same or greater impact on strengthening the legs. Ankle weights focus on building strength and tone over aerobic endurance. For instance wearing ankle weights while running or walking is likely to make the legs fatigue before the heart and lungs begin to tire, which is useful for building leg strength, but not as useful for building up the strength of the heart and lungs.
Because the weight is placed toward the end of the leg, the leverage that the weight places on the leg is high whenever the legs are extended. This means that a relatively light ankle weight can have a large impact on the difficulty of an exercise. For instance, wearing two 0.907kg. ankle weights will increase the difficulty of walking much more than wearing a 1.81kg, backpack, because the backpack only exerts pressure on the body. The ankle weights exert pressure on each leg at a point away from the body's centre of mass.
Another benefit of ankle weights is that adding resistance to the legs allows for new strengthening exercises. Normally simple actions such as moving a leg out to one side or straight ahead would not be an efficient exercise for a fit athlete, but adding a little weight to the legs can transform simple motions into difficult exercises. They are also very useful for increasing the difficulty of body weight resistance exercises such as pull ups and dips.
Ankle weights are generally comfortable to use. The material is soft on the skin and weights attach securely so you can focus on exercise instead of the weights. Ankle weights made of granular materials like sand or pellets are also much safer than solid free weights when dropped; a 1.13kg. ankle weight filled with sand can be dropped on the foot without significant damage, while an iron dumbbell of the same weight can easily break a bone.
Despite their advantages, ankle weights can also have some significant drawbacks. Ankle weights cause more impact on joints which can increase the chance of injury. Ankle weights are not recommended for running or walking. Extended use of ankle weights can cause hyper extension in joints after the weights are removed.