What's more effective, biking for 5 kilos, or 30 mins?

[Renniee]

I'm gonna go biking around my neighborhood (when the snow melts), it has a lot of hills.
What would be more effective?

Please and thanks<3
-Renniee.ox
I'm going to go biking, 5-6 times a week, btw o_o

hopping to loose atlease... 30 lbs before summer. (yes, I will be eating healthy too).

 

[marcoG]

30 mins. Start out nice and easy for the first 5 minutes, then you need to adjust your speed to the terrain so that your heart rate goes up higher than 120 bpm. Your heart should not be racing too much though, and your breathing should be faster but controlled. Your goal is to continue like that for at least 20 more minutes. Then ease up for 5 minutes. That will give you Maximum burn.