Do you know that your upper body muscles are easier to build than your lower body muscles?
It is always a hard game for bodybuilders to develop their legs. When you train your legs hard, you are already training 80% of your muscles including your heart and lungs. This helps to build up your stamina.
Based on experience, sprinting is better than jogging and lunges are better than squats. 30-45 minutes of smart workout works better than 2 hours.