Those things would likely be very easy for a competitive gymnast. The former D1 gymnasts I have worked with have flown right through all the exercise progressions, and we're talking out of shape 30-somethings with kids. They're just built to be athletes.

Not really sure about the rationale for putting you on a spin bike for 20 min. From what you said, your quads weren't the issue.

Another suggestion: Try the Thomas test. Depending on what it tells you, you may need to stretch your hip flexors. Via the same reciprocal inhibition mechanism I mentioned before, tight hip flexors lead to underactive glutes, which lead to overactive hamstrings and adductor magnus.