If you are serious about improving your fitness, a Heart-rate Monitor could be as simple as keeping track of your exercise zones. Each zone improves different areas of fitness and competence. The moderate region of 70 to 80% improves your aerobic fitness.
Currently, there are some excellent heart-rate monitors and not just the Polar brand. They are more comfortable to wear and more accessible to download your results. The weight loss is not the only essential gains at 60 to 70% of your maximum heart rate, but improved fitness could help you live a healthy lifestyle and may even increase your lifespan.
The new heart-rate monitors now come with the ability to adjust the zones according to the person physiology and adapted as the person gains fitness.
It is crucial before attempting any exercise to go and see a medical practitioner.
I will road test a heart-rate monitor soon to see what benefits I gain from it. (Due August 2019 due to new personal fitness goals)