Weight Spentim or Justrack

Hi Charlie, i have a question for you,
i guess you could help me a lot.

  • How can a coach know when the athletes ( sprinters ) need more or less weight work in his program ?

I´m asking because there are 4 runners training with me ( ages 21, 24, 26 and 27 - PB 12.2s / 11.8s / 12.0s / 11.1s respectively ).
For 200m three of them are running over 26s ( 26.3s / 26.0s / 26.8s resp.)
and one ( oldest ) is running 23.0s.
The oldest and fastest is a “close mind guy” and he hates weight work same for plyometric exercises, he just perform some push-ups twice a week ( 6 sets of 16 as fast as he can with feet over a chair ) the other three are performing weight work with max loads ( on wednesdays followed by rest day on thursdays ) and plyo´s on fridays ( followed by a rest day on sundays ).