In before the standard “teach better” response

I have been teaching for 12 years and have never had a student who cannot feel the pulse.

I have had students whose sense of time is not as good as others, but typically when a student is constantly behind the beat it is because they really are not trying hard enough and The teacher is not persistent in making their feet or playing be in time. A metronome should be used in class every day. I insist that students starting in sixth grade band have a metronome present in all of the rehearsals and used most of the time. I also insist that the students tap their foot while they play.

Do not be so quick to put your students on the sideline for marching band. Have them on the field moving their feet. They will not get better if they are not practicing actively.