You don’t have to test your one rep max every other month in order have an idea of what you can lift. In fact, I would not recommend maxing out on the same lifts more than a few times a year. The reason being is that anytime you are truly testing your max, there is a higher rate of failure. This is perfectly alright because if it is your true one rep max, everything has to go just right in order to hit the lift. If you are constantly failing at lifts, not only are you playing mind games with yourself, but you are also teaching your body to fail instead of succeed. Developing a motor plan for failure is not the type of adaption you want. Instead, to get your body used to succeeding, work primarily to hit rep records for yourself in between testing days. You can use an equation to figure out your perceived 1 rep max so that you can still tell if you are making progress. The equation is as follows: [(Weight Lifted * # Reps) * .0333] + Weight Lifted = Perceived 1 Rep Max