If you can squeeze your workout into half an hour, even better.
But whatever you do, make it count. When you work out, work hard. Keep the intensity up. Get sweaty.
Watching films, making casual phone calls to friends or leg pressing 11kg are nothing that should ever be witnessed at the gym - and if you are guilty of these you might has well have stayed at home.
WORK HARD OR GO (/STAY AT) HOME.