Question

A student has a resting heart rate of 72 beats per minute and a maximum heart rate of 196 beats per minute. According to the Karvonen Formula, what will be the target heart rate at 70% intensity?

• A. 146.8 bpm
• B. 158.8 bpm
• C. 164.2 bpm
• D. 172.4 bpm

Hint:

Always remember to calculate the Heart Rate Reserve (HRR) first by subtracting RHR from MHR.
A common mistake is directly multiplying the intensity percentage by the maximum heart rate.
Ensure you always add the resting heart rate back at the final step of the calculation.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The Karvonen Formula is a mathematical method used in sports physiology to calculate an individual's target heart rate (THR) for safe and effective aerobic exercise training. Unlike basic training formulas that only use maximum heart rate, the Karvonen method incorporates an individual's resting heart rate to establish a metric known as the Heart Rate Reserve (HRR). This factor makes the training intensity zones highly individualized and specific to a person's current fitness level.
Step 2: Key Formula or Approach:
The Karvonen model uses a sequence of two main equations: 1. Heart Rate Reserve (HRR): $$ \text{HRR} = \text{HR}_{\text{max}} - \text{HR}_{\text{rest}} $$ 2. Target Heart Rate (THR): $$ \text{THR} = (\text{HRR} \times \text{Intensity %}) + \text{HR}_{\text{rest}} $$ Let's extract the variables given in the problem statement: - Resting Heart Rate ($\text{HR}_{\text{rest}}$) = $72 \text{ bpm}$ - Maximum Heart Rate ($\text{HR}_{\text{max}}$) = $196 \text{ bpm}$ - Exercise Intensity Factor = $70% = 0.70$
Step 3: Detailed Explanation:
Let's solve the equations step-by-step using our parameters: 1. Calculate the Heart Rate Reserve (HRR): Subtract the resting pulse from the maximum ceiling pulse rate: $$ \text{HRR} = 196 \text{ bpm} - 72 \text{ bpm} = 124 \text{ bpm} $$ This value represents the working range of extra beats available for physical exertion. 2. Calculate the Target Heart Rate (THR) at 70% Intensity: Multiply the reserve range by the decimal intensity factor, and add back the initial resting baseline offset: $$ \text{THR} = (124 \times 0.70) + 72 $$ $$ \text{THR} = 86.8 + 72 $$ $$ \text{THR} = 158.8 \text{ bpm} $$ This calculated target pulse value exactly matches option (B).
Step 4: Final Answer:
The target heart rate at 70% intensity according to the Karvonen Formula is 158.8 bpm.