Friday, May 25, 2007

Keep Trucking!

Exercise tip:

Aerobic exercise is a great way to stay in shape and burn fat. We often get comfortable in our routines and stop challenging ourselves. In order to keep getting results it’s important to keep your exercise intensity up. Keep pushing yourself but remember if you can’t talk during your exercise your pushing to hard. Now get out there; walk, swim or jog but stay active!
Have a great day!

Wednesday, May 2, 2007

Calculating your Target Heart Rate

Maximizing your aerobic workout can be tricky. Most of us just jump on the treadmill, pick a setting and hope for the best. A great way of reaching your fitness goals safely and more efficiently is by adding your heart rate to the exercise equation.

Target heart Rate

Your Maximum Heart rate is the highest capacity at which your heart is able to perform in beats per minute (bpm). If your maximum heart rate is 180bpm that means your heart can not beat more than 180 times per minute while satisfying your bodies demand for oxygen and nutrition.
Your Target heart rate is quite simply a percentage of your maximum heart rate at which you chose to exercise. Using your target heart rate during exercise maximizes safety and work out efficiency. The equation for finding your standardized maximum heart is 220bpm minus your age. For example; if you’re 35 years of age your standardized maximum heart rate is 220-35. Though this standard is excellent for establish maximum heart rate, calculating your target heart rate based on it alone can be inaccurate. The equation is effective for setting general population guidelines but can be inaccurate for the individual. Your maximum heart rate can vary by as much as plus or minus 10 to 12 bpm of the standard.
In order to calculate a more accurate target heart rate the Karvonen Formula is widely used. The Karvonen Formula uses the 220 bpm general standard as a basis of calculation. However, it is more accurate as it adds individual resting heart rate to the equation. Your resting heart rate is the bpm of your heart when you body is at rest. The best time take your resting heart rate is as soon as you wake up in the morning preferably while still in bed.

Safety

Safety is the most important consideration when starting a fitness routine. Exercising at high intensity (elevated heart rate) can be dangerous for those with health conditions or a previously sedentary life style. One of the primary benefits of exercising within percentiles of your maximum heart rate is increased safety. Heart attacks have been known to occur after high intensity workouts. This phenomenon generally afflicts those with health conditions who do not consult their doctors prior to embarking on a fitness program. People who have sedentary life styles (i.e. little or no exercise for 6 months to a year) are also at risk.
An effective way to avoid this is by starting out slowly. Improve your cardiovascular capacity by starting aerobic activities at lower intensities before graduating to higher intensity workouts. If you have a health condition your doctor may suggest keeping your target heart rate at 20% to 45% of your maximum. If you have a sedentary lifestyle, the general recommendation is that you start at 40% to 60% of your maximum heart rate. Depending on age, health and fitness, you can graduate to 60% to 90% of your maximum heart rate after at least 4 to 6 weeks of low intensity workouts. Remember if you have any health concerns, are overweight or have any doubt, consult your doctor, he/she will let you know what exercise intensity is right for you.

Maximizing your performance

Knowing your target heart rate can help you design a fitness program tailored to help you get the most from your workouts. Over time an aerobic program will become easier to perform. For instance, you’ve been going to the gym for several months. You jump on the elliptical trainer for 30 min set at the same fitness program each time. At first the weight seems to just fall off. After 2 months you notice that you’re not making the same progress you were. One of the reasons for this plateau may be a drop in your workout intensity.
When you started your aerobic routine your body was working harder to get the same thing done. Your heart is now used to the activity and doesn’t have to work as hard to meet your bodies demands. After your workout, have you noticed that you’re not as tired as you used to be? Aerobic workouts are like practicing an instrument. You get better with time and repetition but you won’t improve without new challenges. What this means to your work out is you have to step it up a notch. Make sure you increase the intensity of your work out periodically. You can do this by changing the target heart rate at which you exercise, ex: from 65% to 75%. Also, calculate your target heart rate about every 6 to 8 weeks. Increase in aerobic capacity is generally marked by a drop in your resting heart rate. Using the Karvonen Formula to recalculate your target heart rate will help you continue to achieve fitness goals and maintain aerobic progress. Recommended target heart rates for healthy active adults (active= exercise 2 to 3 times a week for 30min or more) is 65% to 90% of your maximum heart rate.

Calculating Your Target Heart Rate

Karvonen Formula: Target heart rate = ([maximum heart rate - resting heart rate] x percentage of maximum heart desired) + resting heart rate.

I know it looks a little complicated but trust me it isn’t. First get your resting heart rate. As previously mentioned, the best time to take your resting heart rate is first thing in the morning. Take your pulse for a period of ten seconds (tip: start counting your pulse at zero not at one), multiply the result by 6 and you have your resting heart rate per minute. Ex: you count 11 beats in a 10 second period, multiply 11 by 6, your bpm is 66. Second, to calculate your maximum heart rate subtract your age from 220bpm. EX: 220- 32 (age) = maximum heart rate. Third, input the information in Karvonen’s Formula keeping your desired percentages in mind.

Example: Lucy is 30 years old. She has a desk job, wants to lose 30 lbs and hasn't exercised regularly in over 5 years. She has just started a cardio workout at home. She is often short of breath and exhausted after her workout. She heard that in the first 4 to 6 weeks of starting a fitness program she should keep her target heart rate between 45% and 65%. In order to maximize her progress she decides to monitor her heart rate. To find her target heart rates she must do the following. Calculate her maximum heart rate, find out her resting heart rate, then calculate her target heart rates. Her maximum heart rate is 220 bpm - 30 (her age). Therefore Lucy's Maximum heart rate is 190. She took her pulse at rest for 10 sec and counted 12 beats for a 10 sec period. Her resting heart rate is 72. From here she can find her target heart rate by entering it into the equation listed above.

190 Maximum Heart Rate
72 Resting heart Rate
45% percentage lower limit of maximum heart rate desired for training

Target heart rate = ([190-72] x 45%) + 72
= ([118] x 45%) + 72
= (118 x 45%) + 72
= (53) + 72
= 125 bpm

125 represents the lowest Lucy wants her heart rate to be during a cardio work out.

Lucy wants the highest percentage of her maximum heart to be 65%. To get this number she substitutes 45% for 65% in the same equation.

Target Heart rate = ([190-72] x 65%) + 72
= (118 x 65%) + 72
= 77 + 72
= 149 bpm

Therefore Lucy wants her pulse to be between 125 bpm and 149 bpm during her aerobic workouts.

note: in calculating % you'll usually have decimal answers ex: 118 x 65% = 76.7, simply round numbers up or down according to basic math rules.

Factoring target heart rates into your aerobic routine is a great way to exercise safely monitor cardiovascular improvement, and individualize your aerobic routine. Remember it's just as important not push yourself to hard as it is to make sure you're working hard enough. Have fun and sweat!


References:

American Council on Exercise. ACE Personal Trainer Manual: The Ultimate Resource for Fitness Professional. San Diego: American Council on Exercise, 2003.

YMCA. YMCA's Fitness Leader's Basic Theory Manual. Toronto: YMCA Canada, 1999