Question: what are the quick exercises?
Answer: Sit-Ups. Basic, but effective. ... 
Crunches. These bite-size versions of the whole enchilada isolate smaller, deeper abdominal muscles in their motion. ... 
Bicycles. Lie on your back feet in the air, knees bent. ... 
Planks. ... 
Jumping Jacks. ... 
Burpees. ... 
Squats. ... 
Lunges.