rollerskating vs rollerblading

jodigrengs

I have been roller skating my entire life. I usually can skate down the highway fast enough to get my heart rate up and keep it there. I usually do about 45 minutes. MFP under rollerblading, 45 minutes it's 621 calories. Under skating, roller(rollerblading) 45 minutes is 362. Why is there such a difference? Who do I believe? When I rollerskating...I'm not just going for a leisure scoot.