Answer:
In birth I spring forth, in life I unfold. In death I wilt and die, but rebirth restores all.
What you become during a workout?
What is it that no man ever saw, which never was, but always will be?
What can be white and yellow at the same time?
What has many keys but cannot open a single lock or door?
People take me on walks and I run and have fun. What am I?