Cardio on a excerise bike?

Question

Is it better to do 15 minutes all out (balls to the wall) or 30 minutes relaxed?

5'7 158lbs 27 years old
My exercise bike sucks, it has no resistance. It's like biking down hill. I have to go balls to the wall just to feel like I'm getting a workout but it's really hard to go all out for long periods of time. I'm going to by ankle weights to help.

I'm just starting out, I plan to get to 45 minutes every other day but right now I'm just taking baby steps to get there.

Answer 1

A combination...for the same reason competitive distance cyclists and runners do some shorter workouts to boost speed.

1. 15-20 minute interval-type workouts (pretty much balls-to-the-wall...think 160-170bpm heart rate, I know from experience it is possible to do up to about 182, but proceed at your own risk) will help you build muscle and a stronger heart, giving you ability to hold a higher pace more comfortably during longer workouts. Also note, just having larger muscles alone helps you burn fat (your heart burns fat pumping blood through them). Hill/high-resistance workouts are great for this kind of "speed-building".

2. Also do ideally 45 minute+ workouts (140-160bpm) to burn fat (these obviously must be over 20 minutes, that's when your body starts burning fat and not carbs for fuel).
Note your pace at these will naturally become better if you alternate 15 minute workouts on days in between your 45 minute workouts.

BTW, I am 26 and I am using my own heart rates as a guide...I'm not just making these figures up.

Answer 2

i do like an hour and a half a day up to 16 miles a day..already i am liking what i see when i am naked and that is what counts right! its better for fat burning to go a long distance at a low incline for best results for fat burning u need to get heart rate up to at least 130 though that depends on ur age weight and height