Can't afford or don't want to pay for a gym membership? Make your own frugal workout circuit using things around your house. I lift a cinder block (wearing gloves). I also use 2 resistance bands at the same time wrapped around a pole.
Put on a fast paced workout song and do as many reps of stretches, pumps and lifts as you can. Let the song play twice for a 5-6 minute high intensity workout. Guarantee you'll be sweating. Don't forget proper form and do some air squats to work your legs. You can also lean on the brick to do push-ups. Try it tonight when you get home or in the morning before you leave for work. Be safe. (You can only hold your stomach in for so many years - Burt Reynolds)