Im not sure if this is the case for other people but for me nothing beats a good cardio session to get the sweat dripping.. Either a good hard run or HIIT/circuit i just walk away (completely stuffed) feeling alive and well.. Dont get me wrong i love a good weight session aswell but i feel that cardio gets my mind and body in the zone!! Even the next day i still feel good about myself after it. Does it help release serotonin in our brains??