Is it harder for ladies to stay fit than men?

Yes, as they age: Research shows it is harder for women to stay fit than men as they age but there is no gender difference among younger adults. Menopause involves hormonal change that makes it more difficult for women to maintain muscle mass. Women tend to carry less muscle & more fat than men. Protein-rich diets and resistance exercises are recommended.

Likely, no: Never heard of this reported. I think many women are better at sticking with a plan, but easier/harder to stay fit ? Fitness is a way of life, and depends upon the person. If one has free time (i.e. Retired) it may be easier to keep with a program, whether male / female.