Off track How devices measured a marathon

Misfit Ray (£29.99) 68pc 17.8 miles

Garmin Forerunner 35 (£130) 68pc 17.8 miles

Samsung Gear Fit Pro 2 (£209) 86pc, 22.55 miles

Tom Tom Spark 3 (£199) 96pc, 25.17 miles

Fitbit Ace (£80) 97pc, 25.43 miles

Polar A370 (£170) 96pc, 25.17 miles

Garmin Vivoactive HR (£165) 98pc, 25.7 miles

Huawei Watch 2 Sport (£279) 99pc, 26.5 miles

Apple Watch Series 1 (£249) 99pc, 26.5 miles