High blood pressure

I am a personal trainer and nutritionist, a career I have done for the past 17 years.  I exercise regularly doing 40 mins cardio, 30 mins yoga, 40 mins weights resistance and swimming on a daily basis.  My diet is also clean eating little meat no dairy with good carbs, proteins, fruit and lots of green veg enough to work my system.  I went to the shoppers and took my BP 2 weeks ago and the readings were 159/110 pulse 115.  I was alarmed because I live a clean life and my Bp was always 110/70 pulse 60 in the past.  I monitered it over 2 weeks and it still did not budgestaying at 159/110 p115 so I booked an appointment with my gp.  I had 4 readings taken which were 118/70 p60 116/68 p59 114/68 p69 you get the picture.  I asked why it was high at the shoppers.  The answer was surprising.  My biceps are 18 inches and the bp machines are for standard sized biceps so my circulation was cut off causing my bp to grossly spike.  At my doctors they have cuff sizes for larger biceps or obese people so be aware big fitness guys or girls if you get a high reading at your local shoppers do not be alarmed until you visit your GP.