Following the advice from Joe Cross in The Joe Show, I immediately purchased a mini-trampoline on January 4, and started short exercise during a break at home. It made me tired so quickly (probably after 50 jumps for 1-2 minutes) on the first day, but the number of my jump within my comfort zone increased to about 120-150 for 3-5 minutes. As I stay in my comfort zone, I do not sweat, and my heart rate increase only slightly, but it is so fun like a low-intensity aerobic exercise or dancing.
Actually I have been just dancing on the trampoline like a young dancer in music PV, by singing a song in my head and improvising the cleography all by myself. It was a lot of fun and a great stress-reliever.
5-minute-long exercise on trampoline is equivalent to 20 minutes of jogging. So it is a great way to get active in the winter time while staying at home. Joe Cross recommends to do trampoline exercise during the commercial break of TV. When the commercial ends, you can enjoy lazing yourself for so long without worrying about getting excessive fat or losing muscles.