[font size="1" color="#FF0000"]LAST EDITED ON Jan-23-02 AT 09:12AM (Est)[/font][p]
Hi Olga,
You should be able to find sources online, or even books on heart rate monitors at amazon. I have an article right here from the magazine Fitness RX (premiere)
It says..."Your range is defined as 70-75% of your maximum HR. This is determined by the simple formula: 220-(your age)x.70 and .75 respectively..... So, you will want to keep your hr b/w 130-140 (for the example used) for a solid 45 mins. According to Cathy (sassin), anything much higher will demand too much energy for fat to satisfy, causing the body to switch to muscle glycogen for fuel. Anything lower, and you're not burning fat as effieciently. .....
There are other factors that can distract you from keeping you HR in your range (talking, reading,...) Therefore, Cathy insists you wear a HR monitor or use the HR monitoring handles on equipment, if so equipped. If not, you will have to check your pulse every few minutes. Perceived HR is unacceptable. If you want to burn the most amount of fat for your time, keep your HR in your range. Remember, I'm talking about burning fat, not increasing endurance. Contrary to popular opinion, they are 2 entirely different disciplines. " ( and it goes on for 2 more paragraphs).
The new Energy magazine (jan/feb issue) also has an article on HR monitors right now. Its a 4 page article, but has a small graph:
Zone........ %of Max HR (avg) .....Training Effect
Rest & Recovery.... 30-60...........Little to none
Aerobic Fitness.... 60-80...........Fat burning,aerobic
Anaerobic fitness...80-100.... Speed, power,Peak Fitness
The pulse range that lies b/w your aerobic threshold and about 75 % to 85% of your Max HR is your "aerobic zone", which is your fat-burning zone. In this zone, your body burns mostly fat for fuel, and burns a lot of it, because the intensity level is fairly high.
The top end of you Aerobic Zone is called the "anaerobic Threshold." This thredhold climbs higher as your conditioning improves, from the as low as 70 % of Max HR for sedentary to over 90% of Max HR for Ironman triathletes like Sally Edwards (who has several books on heart rate monitoring). The pulse range b/w your anaerobic threshold and you Max HR is called your "anaerobic zone." The higher you go in this zone, the more your body burns carbohydrates instead of fat for energy.
It's an interesting article that starts out talking about a gal that lost 85 lbs by using a HR monitor, realizing that she had been working too hard, and slowing down helped her to work out longer and burn more total calories.
The article also gives some advice on choosing a HR monitor.
Personally I think they are fun toys, but I don't worry too much about going over my target HR, since ultimately it's still calories we're burning. Hope that helps.
Renee