Safety guidelines when using MTB clipless pedals on a road bike Yesterday, I went for a ride and my legs felt really great (hadn't been cycling for about 2 weeks) so when I was climbing on a hill, I decided to go on a full blown sprint and unfortunately... somehow my leg got released from the pedal and on the push down, my foot hit the ground and that was enough to get myself flying over the bars.

I got used to the regular road bike clipless pedals and that never would've happened with them, what should I do in order to not fly over the bars again on my next sprint?

I use the clipless MTB pedals on my road because the extra I had really helped me with my knee.

Solution:
It's quite apparent that the springs were just too loose.

I can now lift the bike with the shoe on it easily.
This answer is for SPD pedals, which are the most common MTB pedals. Other systems do not have multi release cleat, and some don't even have adjustable springs.

First: make sure you do not have multi-release cleats. They are designed to release when pulled up hard enough, and can be distinguished by letter "M" stamped to them. If the cleats are too worn to tell whether they have the marking, it's probably best to replace them anyway.

Second: Adjust the release spring tension so that the pedals are easy to unclip but not any looser. Too loose pedals may release unintentionally.

Third: If these do not help, it's probably time for new pedals.