[FitFileId{type=ACTIVITY, manufacturer=15, product=9001, serial_number=1701},
FitDeveloperData{application_id=[1,1,2,3,5,8,13,21,34,55,89,144,233,121,98,219], developer_data_index=0},
FitFieldDescription{developer_data_index=0, field_definition_number=0, fit_base_type_id=1, field_name=doughnuts_earned, units=doughnuts},
FitRecord{doughnuts_earned=1, heart_rate=140, cadence=88, distance=510.0, speed=47.488},
FitRecord{doughnuts_earned=2, heart_rate=143, cadence=90, distance=2080.0, speed=36.416},
FitRecord{doughnuts_earned=3, heart_rate=144, cadence=92, distance=3710.0, speed=35.344}]