The Health & Fitness Assessment – Resting Heart Rate, Blood Pressure, & Body Composition
By Karyn Gallivan, MS, ATC, CSCS, NSCA-CPT, NASM-CPT
Contributor, Sports & Fitness Network
Last month (The Health and Fitness Assessment, Part 1), I discussed the fitness evaluation process and its components. In this installment, we will look at resting heart rate, blood pressure, and body composition.
Resting Heart Rate and Blood Pressure
Determination of resting heart rate (RHR) and resting blood pressure (RBP) should, ideally, be conducted after the member has been allowed to sit quietly for five minutes.
The most common method for determining RHR is the radial palpation technique.
Palpate the radial artery at the base of the thumb (lateral to the mass of wrist tendons) using index and middle fingers. Count the pulse for a period of 10 seconds and multiply by six. Record the results in beats per minute (bpm).
To determine RBP, wrap the cuff firmly around the upper arm at heart level, aligning the cuff with the brachial artery. The appropriate cuff size will be ensured when the bladder within the cuff encircles at least 80 percent of the member’s upper arm (most adults will use a large cuff size). The stethoscope bell is placed below the antecubital space over the brachial artery, with the bevel on the earpieces facing toward the front. Rapidly inflate the cuff 20 mmHg above the first Korotkoff sound, and then slowly release pressure at a rate not exceeding 5 mmHg per second. The first sound heard represents systolic blood pressure (SBP). Continue to release pressure and note when the sound becomes muffled and then finally disappears. Just prior to when the sound disappears is used for classification of diastolic blood pressure (DBP). A minimum of two measurements, separated by one minute, should be taken, with the results and goals explained to your member.
The following classifications of RBP are adapted from a publication of the National Institute of Health:
- Normal: Less than 120/80
- Pre-Hypertension: 120-139/80-89
- Stage 1 Hypertension: 140-159/90-99
- Stage 2 Hypertension: 160 and above/100 and above
Body composition describes the relative proportion of fat to fat-free mass. Excess body fat places an individual at increased risk for development of diseases such as type 2 diabetes, stroke and hypertension. A number of laboratory and field techniques have been developed to assess this important component of physical fitness.
A common and reliable field method, which correlates well to hydrostatic weighing, is to estimate body composition from skinfold measurements. The skinfold technique is based on the fact that subcutaneous fat is proportional to the total amount of body fat. It provides a reliable estimate of your member’s body density, which is used to determine percent body fat. This relationship, however, depends considerably on your member’s age, gender and ethnicity. Population-specific equations to convert body density to percent fat reflect these variables.
General procedures for skinfold measurements are the following:
Measurements should be taken on the member’s right side while standing.
- The caliper should be placed 1cm away from the thumb and finger, perpendicular and halfway between the base and crest of the fold.
- Maintain the pinch while reading the caliper.
- Obtain your reading in one to two seconds.
- Take duplicate measurements at each site, retesting if not within 1 to 2 mm.
- Rotate through measurement sites to ensure the skin has time to return to normal.
The skinfold sites used are dependent on the generalized skinfold equation that converts skinfolds into body density. Such equations to convert skinfolds into body density can be found in ACSM’s Guidelines. A common equation includes the chest, abdomen and thigh (men), and triceps, suprailiac and thigh (women) skinfolds. As noted, population-specific equations are then used to convert body density into percent body fat.
ACSM also recommends measurement of waist circumference, since body fat distribution, particularly in the abdomen, is an important predictor of a number of health risks. Measurements should be made with a flexible yet inelastic tape measure placed lightly (avoid compressing the skin) at the narrowest part of the torso above the umbilicus and below the xiphoid process. This process should be repeated until duplicate measures are within 5 mm. Waist circumferences <70 cm in women and <80 cm in men are considered low risk for associated health risks (CAD, hypertension, type 2 diabetes, etc.).
After these resting measurements are complete, the next step is the actual fitness testing. Next time I will discuss tests for Cardiorespiratory Endurance (submaximal exercise test), Muscular fitness, & Flexibility.