I'm a bigger fan of guys gaining weight naturally with age. Hit the weights, eat right, the strength will come. I'd hate to see him pack weight on and lose some of his agility/spring.
The rest of the NBA is already screwed. Rudy has completely changed the fortunes of the Jazz. I agree with those who are saying to just let Rudy do what he's done in the past, he'll get gradually better and that's enough. Just don't get seriously injured - at this point that would be the only thing preventing Rudy from being a star - perhaps superstar - in this league for the next 10 years.
Why does everyone think Karl Malone is some sort of athletic training genius? He worked his *** off and had insanely superior genetics. I'd much rather have him working with a professional trainer than lifting pigs and running through mud bogs with malone.