I disagree- I think it's most important for those who are reluctant. These are probably the children who are not doing exercise outside school either and would benefit most from appropriate lessons
Have you seen the many posts from those of us who were active outside school but hated PE?
Oh I well remember the day when the PE teacher had us all doing 10 sit ups. When she sneered at me and asked why I wasn't doing it I said I'd finished.
So she made me do them again, and I did while her sporty favourites were struggling with their first 10.
She was so visibly pissed off.
We always did sit up and press ups as part of out warm up at Ju-Jitsu.
I think there should be some form of exercise in schools but it doesn't need to be PE as it currently is. Keep PE teachers for GCSEs but bring in instructors / people qualified to teach outside school and have a range of activities, ballroom dancing, tumbling, cheerleading, martial arts, fencing, spinning.