We asked Dr Joseph Ciccolo, an exercise scientist and assistant professor at Brown University, to outline how weight, health, and running performance are linked. If you’re unsure if you’re at a healthy weight, ask your doctor or use our BMI calculator.
Carrying excess weight puts pressure on your joints and can lead to hip, knee, and ankle injuries, says Ciccolo. Gradually increase weekly mileage to avoid excess strain on your joints.
You may not be able to chase down a PB if you’re carrying extra weight, but you’ll certainly have the energy to run hard and are at little risk of injury.
For most runners, this is the best place to be. With proper training, your risk of injury is low and you should feel energetic, fast, and emotionally balanced.
Stress fractures become more likely because your bones suffer from being under-nourished. Also, you’ll fatigue earlier during runs and may suffer uncomfortable post-exercise symptoms such as headaches and lethargy.
If you’re under-nourished, your pace suffers as your body breaks down muscle for energy instead of using food as fuel. Loss of muscle also disrupts hormone function.
If you’ve basically stopped eating, you tax your heart so much that you’re at risk of a heart attack or stroke. Eating disorders are also considered psychiatric illnesses.