Please take a look at Gus, a woman in her 90s who has recently started to train at Rip's gym and has improved her quality of life such that she no longer requires her walker.
It's hard to hurt yourself if you truly read the book, because if you start with an empty bar and only add small amounts of weight using the proper form (as the book instructs) it's tough to hurt yourself.
If anyone needs some help with barbell form you can drop into the forums where coaches will gladly review a video for you, or if necessary find someone to help you in person.
And before I fall down the rabbit hole of repeating Rip's gospel word for word, what a coach says they do for an elite athlete has little bearing on the general population. Elite athelets are genetic freaks that could be trained in many ways and still achieve their results.
Lifting heavy is not going to slow you down or make you big, it's going to get you strong. Training for strength and practicing your sport of choice will just make you a stronger version of your previous self. If you train and eat like a power lifter you are not going to be able to maintain your 3:30 marathon time, but if you add in properly programmed strength training for the goals you are looking to achieve, it is petty hard to argue that being stronger is worse than being weaker all other things being equal.