Venu Sq owner using Garmin HRM Dual chest strap. Older runner 60 years, max heart rate under 170. At the start of my runs it shows crazy heart rate numbers. Today it showed my heart rate at 165 then 30 seconds later it showed 113 and stayed below 120 for the rest of my easy run today. It showed numbers in the 160s even in 170s for the first ten minutes. Pace never changed all run; flat route.