just 10-15 minutes: get up and stand the window, breath deeply, you do 10 jumping jacks, 10 pushups, 10 squats-> your heart starts to beat faster, you stretch your arms. touch your toes, roll your shoulder, it can fosten you so much, -> YOU FEEL LIGHT, YOU FEEL AWAKE, YOU FEEL ALIVE AND YOU CAN DO EVERYTHING MORE PRODUCTIVE AND HAPPY