Ankle weights are wearable resistance devices, typically ranging from one to five pounds, that strap around the lower legs. They are a popular tool for individuals seeking to make routine movements, such as walking, more challenging. The central question for many users is whether this added resistance translates into a meaningful increase in energy expenditure. This article examines the impact of these weights on the body’s energy demands, reviewing the underlying science and practical effectiveness.
The Physiological Mechanism of Calorie Increase
The body’s energy expenditure is directly related to the amount of work performed, and adding mass to the limbs fundamentally increases this workload. When ankle weights are worn, the body must expend more energy to lift and swing the weighted limb with each step. This increase in physical work requires a measurable rise in oxygen consumption.
The added resistance forces the lower body muscles to recruit more fibers to stabilize and propel the legs forward. Specifically, the hip flexors, quadriceps, and calf muscles must work harder against the downward pull and the momentum of the weight. This heightened muscle recruitment and cardiovascular demand elevates the metabolic rate. Studies have shown that the magnitude of this physiological response is significantly greater when weights are placed distally, like at the ankles, compared to placing the same weight closer to the body’s center of mass.
Practical Calorie Burn: Effectiveness During Movement
While the weights technically increase the work done, the actual increase in calorie burn during typical activities is often modest. Research indicates that wearing ankle weights can increase oxygen consumption and energy expenditure by approximately 5 to 15 percent during steady walking. For example, a 150-pound person engaging in a 45-minute walk might burn up to 48 additional calories by using ankle weights.
This marginal percentage increase means that the weights serve more as a way to enhance muscle activation than as a primary tool for caloric change. The effectiveness is highly dependent on the activity and the weight used. During low-impact activities like walking, a light weight (one to three pounds) can increase the effort without severely compromising form.
The impact of ankle weights on energy expenditure can be complicated by changes in movement patterns. Some studies have found that when people wear ankle weights while running, they naturally slow their self-selected pace, which can negate the increase in the rate of oxygen consumption. While the total energy expenditure over a fixed distance may still be higher due to the load, the intensity of the workout does not necessarily increase. For the average person, the small boost in caloric expenditure may not justify the potential for injury, especially when using weights heavier than a few pounds.
Risks of Improper Use and Joint Strain
The distal placement of the weights, far from the body’s core, creates a mechanical disadvantage that can stress the joints. Wearing ankle weights during movement, particularly walking, alters the natural gait mechanics and stride rhythm. This unnatural change in movement pattern can lead to compensatory movements, which may reinforce inefficient habits that persist even after the weights are removed.
The added momentum from a swinging weighted limb places a disproportionate load on the joints of the lower extremity. The repetitive stress can lead to strain on the ankle, knee, and hip joints. Over time, this stress increases the risk of overuse injuries such as tendonitis and ligament strain, particularly in the knees. Health experts caution against using ankle weights during high-speed activities like running or jumping, as the amplified impact forces can accelerate wear and tear on the joints.
Contextualizing Results: Better Ways to Increase Energy Output
Considering the moderate caloric benefit and the orthopedic risk, ankle weights are often an inefficient choice for increasing energy output during cardio. A safer and more effective strategy is to increase the intensity or duration of the activity itself. For instance, walking at a faster pace or incorporating an incline will raise the heart rate and oxygen consumption more effectively.
Alternatively, adding resistance closer to the body’s center of mass provides a similar caloric boost with less joint compromise. A weighted vest, for example, distributes the load evenly across the torso, which helps maintain a more natural movement pattern. Weighted vests can increase caloric output by a comparable 5 to 10 percent but are safer for the joints and more effective for building overall functional strength. For individuals seeking to increase their energy expenditure, these alternatives offer a better balance of effectiveness and injury prevention.