Resting heart rate is dipping into the mid to upper 50s. is this normal?

Certainly can be: There's nothing wrong or unhealthy about a heart rate of 50. Seasoned athletes normally have hr of 50. Within reasonable limits, it's a sign of health to have a slower heart rate and at 32 and with hrs in the 50s, i suspect that you are healthy.

Heart rate: Resting heart rate in the upper 50's may be a sign of excellent aerobic conditioning. If no symptoms it is not a cause for concern.