I notice that it has become fashionable for personal trainers to encourage their erstwhile sedentary, urban, weakling, clients to lift heavy weights.
This is the opposite to the common wisdom of high reps low weights.
If you want to stay injury free then stick with the common sense wisdom of high reps, low weights.
Personal trainers are often a bit obsessed and want everyone to be fit and strong just like them. While that may be a good idea on the face of it really is best to move very slowly into heavier weights.
Personal trainers work out all day.
Most people these days sit at desk and are not well equipped to lift heavy weights.
High Reps — Low Weights.

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