My amstaff is 24mo. Is he at the right age to start training for weight pulling?

I have a mentor, whose well versed in the field. He's teaching me everything I need to know. I'm very excited about training my dog for something I know he'll excel in. The thing is, I love my dog and want him to live to a ripe old age, so I don't want to start him out to young. I also don't want to overwork him. My trainer says he's at the right age to condition him for training. Is 24mo the right age to train a dog for such a grueling sport?