I'm a retired senior with a vintage ('90ish) cross bike in good condition trying to learn how to road bike.
I can pedal pretty well (15-20 mph) on the flats with the big chain ring for long durations but have less strength and little stamina when spinning in the granny gears on grades and hills. I do not run out of breath before my legs give out.
Is there an efficient way to develop improved spinning performance in terms of stamina and strength? Should I be performing leg exercises in terms of lunges, squats, step ups, etc emphasizing quads and knees in addition to biking? I am small of stature, not overweight, and was a marathon wilderness day hiker and habitual daily walker before starting with biking. I believe my cardio capacity is good and I have a low resting heart rate.
Any advice from you experts would be appreciated. I posted a thread in the Training and Nuitrition section but did not get any responses. My thread there may have been too long winded.