Another fact I came across while reading about Greasing the Groove was that the strongest predictor of muscle growth was total weight lifted over time. So, you lift 5lbs 100 times over a week, or 25lbs 4 times a week, and you get similar growth. I’m sure that there are limits here, but this is the basic idea. If you take longer rests, you can usually do more reps in a day, and lift more weight in a week. I’ve put on around 10-12lbs of muscle this way, from doing light body weight movements somewhat often. I’ve also started taking 5-10 minute breaks between climbs and I’m climbing harder than ever.