optimal zone of walking speed and heart rate

Hello, there is really a feature that is essential to me and that we really need. During a sporting activity (especially for walking), it would be good if we could see on the PMOLED screen simultaneous display of the heart rate as well as the speed in kilometers per hour. For people like me who want to lose weight, there is an optimal zone of walking speed and heart rate to allow glycolysis mainly using the triglycerides of fat cells. For my age (47), my heart rate should be between 104 bpm and 115 bpm and my speed should be between 6 km / h and 6.5 km / h.
Technically, this won't take a lot of line of code for your development team and shouldn't take up too much space in watch ROMs.
This addition is only Software and not Hardeware.
In addition, it corresponds to your target audience. Indeed, great athletes take, in general, Garmin, Polar or Sunnto watches, but people like me and friends who have Withings watches, we mainly take your watches for their autonomy and the possibility of monitoring our health ( weight loss is one of them) and occasional sports activities.
When I decide to take a long walk of more than 2 hours I could look at my Withings Scanwatch watch (when will it be released?) And see on the PMOLED screen if I need to speed up my pace or slow my pace pace down. my heart rate and my speed.
Thank you for listening, with the hope that my complaints will be heard by your managers.
Sincerely Ounsi.