I Am Pretty Fit. I Jog Every Second Day, Ride

I am pretty fit. I jog every second day, ride a bike for about an hour the alternate days and try do as much surfing as possible. Yet I have slightly high blood pressure at about 148/70. Do not understand why. I understand and adhere to a good diet, but I do experience slight anxiety. I have no problems in adjusting diet and doing physical exercise, but what mental exercises can be done to control anxiety