For best results workouts should be intense and short. Whatever method you use it should keep your heart rate elevated and breathing increased whilst resting between sets or circuits. Workouts should also be structured and have a purpose.
Rest outside the gym is just as important as the workouts in order to progress and reach your goal. Rushing around all day stressed and going to bed late will dig into your energy reserves. This will diminish energy levels and compromise your workouts and recovery time. This could eventually lead to stress on your immune system and make you more prone to illness. From this a vicious circle presents itself and a future of slow progression begins.