Workouts and Your Body

Resting Heart Rate
The first thing you should do is monitor your resting heart rate. The best time to do this is first thing in the morning – after you use the bathroom since having to go may otherwise elevate your heart rate. Here's what to do.

1. Place your index and middle fingers together on the opposite wrist, about half an inch on the inside of the joint, in line with the index finger.
2. Feel for a pulse by pressing lightly on the artery.
3. Once you find a strong pulse, count the number of beats you feel for one minute.
4. Begin your count with zero. When exercising, it's more practical to take your heart rate for 10 seconds and multiply by six.

Knowing your resting heart rate does not necessarily tell you much – it's a number relative to nothing – but noting changes over time generally indicates a change in your level of fitness. As your heart and cardiovascular system becomes stronger and more efficient, your resting heart rate (RHR) will decrease. This indicates that more blood is being pumped with each beat and that your body is more efficient at extracting oxygen from the blood.

Often we're asked, "What's a good normal resting heart rate?" That's a good question with no real answer. Normal RHR ranges from 60 to 100 beats per minute; the average is approximately 70 for men and 75 for women. Extremely well-conditioned athletes sometimes have heart rates as low as 40 beats per minute. Former tennis great Bjorn Borg was said to have a RHR around 36 beats per minute.

Weight and Body Composition
The "Body Mass Index" (BMI) is a quick way to gauge if you're at a healthy weight. But because it does not differentiate between muscle and fat, or take frame size into account, it is clearly a flawed method. However, for someone who isn't extremely muscular, it's a reasonably accurate and quick method. High BMIs – the bane of many American's existence – are associated with an increase risk of heart disease, hypertension, and diabetes. Here's a chart to look up your BMI:

Body Mass Index

Weight Category	BMI Range	% Above
Normal weight	19-25
Overweight	26-30	20-40%
Obese	31-35	41-100%
Seriously obese	Over 35	Over 100%

Regardless of what the scale says, the best way to determine if you need to lose weight is by measuring your body composition. That's because body composition measurements take your muscle mass in to account and can differentiate between a lean, mean bodybuilder who's covered in muscle and weighs 210 pounds and a couch potato with a gut who's the same height and weight.

There are a variety of tests available in lab settings: Underwater weighing is the gold standard, and skin-fold calipers are dependable and reliable. Other methods such as bioelectrical impedence are impressive looking (and sounding) but notoriously inaccurate. If you don't have access to those tests, here's a quick test you can do to estimate your body fat percentage.

1. Measure your height in inches.
2. Measure the widest part of your hips in inches.
3. Using the chart, take a straight edge and match up each end to your corresponding height and hip girth. The point at which the ruler intersects the middle line is your estimated percent body fat.

Use this chart to estimate the percentage of body fat you carry.