Thank you all for your encouraging replies to my post yesterday. Yes unless I have something wrong with me or I over exercise my heart rate does not go above 100.
The only worrying concern is the Kardia readings which consistently show a variation of between 2.5 and 6.5 squares in one reading. If you can all reassure me that it is the overall result that matters and not the rate at which the heart beats in one reading I will be happy.
The reason I bought the Kardia is not to be fixated by it but because my pulse is usually so quiet that I fiddle about for ages trying different points to try and connect with it and find that very difficult.
Thanks all. This site is fantastic.