a 14 year old boy has a resting heart rate of 76. using lower and upper reserve training percents of 50 and 85 what is his target heart range?

110 to 180

130 to 206

141 to 186

144 to 206

To determine the target heart rate range, we can use the Karvonen formula. The formula is:

Target Heart Rate = Resting Heart Rate + (Heart Rate Reserve * Training Percent)

First, we need to calculate the heart rate reserve (HRR). The HRR is the difference between the maximum heart rate and the resting heart rate. The maximum heart rate can be estimated using the formula: Maximum Heart Rate = 220 - Age.

Let's calculate the maximum heart rate for a 14-year-old boy:
Maximum Heart Rate = 220 - 14 = 206

Now, calculate the heart rate reserve (HRR):
HRR = Maximum Heart Rate - Resting Heart Rate
HRR = 206 - 76 = 130

Finally, calculate the target heart rate range using the lower and upper reserve training percentages.
Lower Target Heart Rate = Resting Heart Rate + (HRR * Lower Training Percent)
Lower Target Heart Rate = 76 + (130 * 0.50) = 76 + 65 = 141

Upper Target Heart Rate = Resting Heart Rate + (HRR * Upper Training Percent)
Upper Target Heart Rate = 76 + (130 * 0.85) = 76 + 110.5 ≈ 186

So, based on the given information, the target heart rate range for the 14-year-old boy is 141 to 186 beats per minute. Therefore, the correct answer is option C: 141 to 186.