is it the same thing/?

Something is better than nothing but in 5 minutes I wouldn't imagine you would build up enough intensity or increase your HR enough to matter much. 5 mins doesn't really give you enough time to increase your HR and really get in a decent workout even if the total time for the day is 60 mins. Your calorie burn for that 60 mins spread throughout the day in 5 min sections would be much lower than if you spent 60 mins at once on the bike or even 30 mins.

If you can take a 30 min block of time to exercise I would imagine it would be better than 5 minutes every hour. Personally I would find it much easier to do a block of time...even if it's 20 mins than trying to do 5 mins every hour

I will say, as the above person stated - 5 minutes is still better than nothing! If you are only capable of doing 5 minutes at a time due to health/lack of health than go with the 5 minutes! 5 minutes will build to 6 minutes, to 7, 8, 9,10, 20, 30 over time. Your breathing will slowly get better, and you will be able to do more. If it's just a "I don't have time" then you need to try and set time aside for yourself to get more than 5 minutes in. ok?