Your dumbbell exercise belongs to strength training. Do strength training first, and then go by bike. Because you are doing small weight dumbbell exercises for the purpose of reducing fat, one group does 0 to 0 times. Do several groups. Spinning bike It is recognized that the effect of reducing fat is better, just look at the amount of sweat. A cycling lesson plus a brisk walk for a while is enough. Just stick to it. The key is to control diet.