The instructions it came with tell you not to wear it while using dumbbells or barbells. As for cardio, I guess it's ok. Mine tends to say I took 20% more steps

The instructions it came with tell you not to wear it while using dumbbells or barbells. As for cardio, I guess it's ok. Mine tends to say I took 20% more steps per day than reported by the pedometer app on my phone. I have no clue which one is more accurate though.