What is "Heart-Rate Control"
"Heart-Rate control" is the greatest invention since sliced bread. Especially if you're interested in weight loss or endurance building.
Heart-rate control refers to the ability of the equipment to monitor your heart-rate, in real time, and to adjust the level of exercise to guide your heart-rate into the zone you've selected.
Best used with a wireless chest strap, which ensures the heart-rate reading is fed continuously to the console as you exercise, the machine will sense when your heart-rate is getting too high or too low. Instantly, the treadmill (for example) will increase speed and incline, just slightly, until your heart-rate increases back above the lower threshold you've set.
This is important for a couple of reasons.
Firstly, the more you exercise, the more fatigued you get. You'll lose track of your heart-rate if you're trying to monitor it yourself, and you'll lose motivation to stick to the goal. You're only human.
Secondly, the best way to lose weight is to get your heart rate to (broadly) 60-70% of maximum. Below that, and you're just wasting your time. Above that, and your brain is telling your body to prepare for the Olympics. This "fat burning zone" is narrow, and without the assistance of a vigilant computer, you're not going to stay in that zone for as long as you should.
So you can tune out, watch the nightly news or daytime soapy, and let the console do the laborious task of monitoring your heart-rate and ensuring it stays in the zone that's best for you.
In closing, heart-rate control is an absolutely awesome feature of modern fitness equipment. It does NOT come in all equipment, but we would urge you to consider a machine that includes a "heart-rate control program".
As an aside, whilst some machines come with "hand-pulse" (which means you place your hands onto two metal slits on the machine in order to measure your pulse rate), this is not nearly as accurate, reliable, or real-time as a chest strap. Yes, some machines come with a HRC Program and Hand-Pulse, but be warned - the HRC Program won't work very well if you don't keep your hands on the metal slits.