Fitness trackers 'overestimate' calorie burning Popular brands of fitness trackers can overestimate the number of calories burned while walking by more than 50%, tests have found.
Researchers at Aberystwyth University found all products - ranging from £20 to £80 in price - were inaccurate during walking and running tests. Dr Rhys Thatcher said devices had an "inherent tendency" to over-measure. Fitbit said its product was based on "extensive research", but others said theirs were "not medical devices". BBC News