Approximately how many calories would this exercise burn?

Break this session into circuits with a few minutes between circuits. Reduce the numbers accordingly:

For 50 use 20 each circuit

for 40 use 20

for 30 use 15

for 20 use 10

for 5 use 10.

Keep track of your heart rate and keep it between these numbers-- 220- your age x .55 and 220- your age x .65

Example- 220-50= 170 170 x .55 = 93 and 170 x .65 = 110 so this person would keep their heart rate between 93 and 110 to promote energy being used from fat cells instead of carbs. Find the values for you using your age.

i don't know how you would do 40 push ups in rapid succession, maybe you're just that good, but you are looking at quite a lot of cals here. you're looking at anything between 200 and 400 cals depending on your height at shape