"Doing more" doesn't always necessarily mean that we are physically active. We also can do more by understanding or connecting our activities to pleasing Krsna. We can chant more, we can remember Krsna more, we can pray more. There are many things that one can increase that will be pleasing to Srila Prabhupada and ultimately will be pleasing to Krsna. It's not necessarily a fact that just by doing more physically that we will be able to obtain the result of all of these efforts together.