Sportline solo 915 mens hrm sports watch with the sportline solo 915 mens hrm sports watch you have the easy access heart rate function to maximise training and set smart targets the use of a hrm monitor should be underestimated and can massively increase your performance and ensure that you can track progress heart rate allows you to measure and visualise your bodies reaction to stress and activity so that you can then compare each session to see how you are progressing and cardio strength i