Is running the best way to lose weight?

Running. Running is a good form of exercise and can definitely help you lose weight. However, it is a high impact exercise and can damage your knees. Any form of cardio exercise that gets your heart rate up is good. Biking (or stationary bike), elliptical machine, rowing, swimming are all great forms of cardio. Maintain your target hr for 30+min to burn fat. Running is fine if your knees can take it.