A) The source is probably not valid because it is based on an opinion.
He or she that wrote it did not go into a lab and see if the resources are true its just based on what he thinks it is.
Skeletal Muscles, Cardiac Muscles, and Smooth Muscles
Answer:
A 17 year old with a resting heart rate of 62 bpm has a maximum hearth rate of 203 bpm, a hearth rate reserve of 141 bpm and target hearth rate between 161 and 182 bpm
Explanation:
Target heart rate is a measure used to calculate the range of heart rate that should be maintained during intense exercise.
Knowing a person's age and resting heart rate (RHR), a target heart rate calculation can be made from the maximum heart rate (MHR) and the hearth rate reserve (HRR)
Data:
- Age: 17 years old
- RHR: 68 bpm
The maximum heart rate is calculated by subtracting age from a constant value of 220, so:
- MHR = 220 - age
- MHR = 220 - 17
- MHR = 203 bpm
HRR is calculated by subtracting the resting heart rate (RHR) from the MHR value:
- HRR = MHR - RHR
- HRR = 203 - 62
- HRR = 141 bpm
THR is obtained by multiplying the HRR by 0.7 and 0.85, to obtain the range of heart rate in which the exercise can be performed.
- THR lower limit = (HRR x 0.7) + RHR Lower THR = (141 x 0.7) + 62 = 160.7 ≈ 161 bpm
- THR top limit = (HRR x 0.85) + RHR THR top = (141 x 0.85) + 62 = 181,85 ≈ 182 bpm
For the 17-year-old, the ideal target heart rate for an intense exercise is between the values of 161 and 182 bpm.
Calories are the energy in food. Your body has a constant demand for energy and uses the calories from food to keep functioning. Energy from calories fuels your every action, from fidgeting to marathon running.
Carbohydrates, fats and proteins are the types of nutrients that contain calories and are the main energy sources for your body. Regardless of where they come from, the calories you eat are either converted to physical energy or stored within your body as fat.
These stored calories will remain in your body as fat unless you use them up, either by reducing calorie intake so that your body must draw on reserves for energy, or by increasing physical activity so that you burn more calories.
Tipping the scale
Your weight is a balancing act, but the equation is simple: If you eat more calories than you burn, you gain weight. And if you eat fewer calories and burn more calories through physical activity, you lose weight.
In general, if you cut 500 to 1,000 calories a day from your typical diet, you'll lose about 1 pound (0.5 kilogram) a week.
It sounds simple. However, it's more complex because when you lose weight, you usually lose a combination of fat, lean tissue and water. Also, because of changes that occur in the body as a result of weight loss, you may need to decrease calories further to continue weight loss.
