If it was me I would NOT try the attempts in the gym for the reason that a training max (TM) is not the same as a competitive max (CM).

From my experience most people have a 10% difference between their TM and CM so it would not be a very good gauge.

The first course of action is to find another meet around the same time frame.

If not then readjust you training for the next meet.

While I personally never had this happen I have trained with people who were doing meets I was not. In this case I trained with them up until the point of a circa max (or final peak) phase. At this point I would go into a de-load or neutral phase and just ride it out while they peaked for the meet. I never liked to peak more than twice per year and did not want to do it if my numbers would not count.

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Dave Tate