@benwallisruns: Wrist heart rate can be 10-20 bpm off, especially during intervals, hills, or even easy runs. That means your training zones could be completely wrong. Chest straps measure your heart's electrical signals, so you get real data you can trust. First run back with the Garmin strap today... sweaty, yes. Worth it? 100%. Smarter data = Smarter training. #runnersofinstagram #runnerlife #basebuilding #runningmotivation #enginebuilding