Done a few runs now and it seems to not actually update to the correct heart rate until more than half way through. This 5k I just ran was very hard effort for me and I know from the start my heart rate was over 165, and I actually slowed down towards the end where it says my heart rate was 187 max. It keeps doing this where it jumps to the correct figure after and its skewing up my data. Is this happening to anyone else? I realise my heart rate wouldn't be 180s from the start and would gradually increase but it wasn't 150 after ten minutes of hard running believe me.