frequency

I have always read that you should only work a muscle once a week. I'd like to increase my chin-ups though. I know a lot of people that do them every morning, or every other morning.

is the once a week rule only for maximizing size?

:huh: The rule I've heard was 48 hours.

muscle requires 48 hours of rest

once a week is for increasing overall body muscle mass, not an individual muscle group

I have always read that you should only work a muscle once a week. I'd like to increase my chin-ups though. I know a lot of people that do them every morning, or every other morning.

is the once a week rule only for maximizing size?

I increased pullups dramatically by doing them everyday, multiple times a day.

It depends on how you work that muscle among many other factors.

I increased pullups dramatically by doing them everyday, multiple times a day.

Yup. As long as you get plenty of sleep, food and water, you can bypass the 48 hour rule.