NASM Certified Personal Trainer · Assessment
NASM Certified Personal Trainer: Fitness Assessments Concepts
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Overview
This chapter covers common fitness tests and the math behind them. You need to estimate maximum heart rate, find a training heart rate, and figure body mass index (BMI). The exam often gives numbers and asks you to work out an answer.
A common estimate of maximum heart rate is 220 minus age. The Karvonen method uses heart rate reserve, which is maximum heart rate minus resting heart rate. You multiply the reserve by the target intensity and then add the resting heart rate back.
BMI is weight in kilograms divided by height in meters squared. It is a quick screening number for groups, but it cannot tell fat from muscle. Adult BMI from 18.5 to 24.9 is in the healthy range.
The Rockport walk test estimates aerobic fitness. The client walks one mile as fast as they can, and the trainer uses the time and heart rate at the end to estimate fitness.
Key concepts
Estimated maximum heart rate
A rough estimate of the highest heart rate a person can reach: 220 minus age. For a 40-year-old, that is 180 beats per minute.
Memory tip220 minus age. It is an estimate, not an exact number.
Karvonen method
Target HR = (max HR - resting HR) x intensity + resting HR. Example: age 40, resting HR 70. (180 - 70) x 0.6 + 70 = 136 beats per minute.
Memory tipSubtract rest, multiply, then add rest back. Do not forget the last step.
Body mass index (BMI)
Weight in kilograms divided by height in meters squared. A 70 kg person who is 1.75 m tall has a BMI of about 22.9.
Memory tipKilograms on top, meters squared on the bottom.
Adult BMI categories
Under 18.5 is underweight, 18.5 to 24.9 is healthy weight, 25 to 29.9 is overweight, and 30 or higher is obesity. BMI does not separate fat from muscle.
Memory tipRemember the cutoffs 18.5, 25, and 30.
Source: US Centers for Disease Control and Prevention (CDC), adult BMI categories · as of 2024
Rockport walk test
A test that estimates aerobic fitness. The client walks one mile as fast as possible, and the time and ending heart rate are used to estimate fitness.
Memory tipRockport = walk one mile, then check time and pulse.
Often tested
- In the Karvonen method, the resting heart rate is added back at the end.
- 220 minus age is only an estimate of maximum heart rate.
- BMI cannot tell muscle from fat, so a muscular person may show a high BMI.
- BMI uses height in meters squared, not plain meters.
Easy to confuse: Two ways to set a target heart rate
| Point | Percent of max HR | Karvonen (heart rate reserve) |
|---|---|---|
| Needs resting HR? | No | Yes |
| Formula | Max HR x intensity | (Max HR - resting HR) x intensity + resting HR |
| Age 40, rest 70, 60% | 180 x 0.6 = 108 | 110 x 0.6 + 70 = 136 |
3 sample questions
Verified practice questions from this unit.
Question 1. Using 220 minus age, what is the estimated maximum heart rate of a 40-year-old?
- ① 260 beats per minute
- ② 180 beats per minute
- ③ 190 beats per minute
- ④ 140 beats per minute
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Answer: ② 180 beats per minute
Key point: HRmax = 220 - age
220 minus 40 equals 180 beats per minute.
Wrong choices
- 260 beats per minute: This adds age instead of subtracting it.
- 190 beats per minute: This does not match 220 minus 40.
- 140 beats per minute: This is too low.
Question 2. Which measurement uses a client's height and weight to place them in a weight category?
- ① Body mass index (BMI)
- ② Waist-to-hip ratio
- ③ Skinfold measurement
- ④ Resting heart rate
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Answer: ① Body mass index (BMI)
Key point: BMI = weight and height
BMI is calculated from weight and height and is used as a general screening measure.
Wrong choices
- Waist-to-hip ratio: This uses two body circumferences.
- Skinfold measurement: This measures fat under the skin with calipers.
- Resting heart rate: This is not related to body size.
Question 3. Which artery is commonly used to take a pulse at the wrist?
- ① Femoral artery
- ② Brachial artery of the thigh
- ③ Radial artery
- ④ Aorta
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Answer: ③ Radial artery
Key point: Wrist pulse = radial artery
The radial artery runs along the thumb side of the wrist and is commonly used to take a pulse.
Wrong choices
- Femoral artery: The femoral artery is in the groin area.
- Brachial artery of the thigh: There is no brachial artery of the thigh.
- Aorta: The aorta is deep in the chest, not at the wrist.