Numerical Tricks and Shortcuts

a) Blood Volume

• For males, a quick estimation of total blood volume:
  • Adults: [Body Weight (in kg)] x 80 ml/kg
• For females, a quick estimation of total blood volume:
  • Adults: [Body Weight (in kg)] x 70 ml/kg

b) Heart Rate

• To find the target heart rate for moderate-intensity aerobic activity for a specific individual, you can follow these steps:
  1. Calculate the individual’s maximum heart rate: 220 - Age (years).
  2. Multiply this maximum heart rate by 50% or 70% (depending on the desired intensity level) to get the target heart rate range.
  3. To find the ideal heart rate during an exercise regimen, simply multiply your maximum heart rate (the highest heart rate you can achieve during vigorous activity) by the exercise intensity percentage.
  • A light exercise intensity is 50-60% of your max, a moderate intensity exercise falls between 60-70% and a vigorous exercise falls between 70-85%.

c) Blood Pressure

• To determine if a blood pressure reading indicates hypertension, follow this rule:
  1. If systolic pressure >=140 mmHg, or diastolic pressure >= 90 mmHg, the individual is considered to have hypertension.

d) Hemoglobin Concentration

• For adult males, a quick reminder of normal hemoglobin concentration:

  • Hemoglobin concentration: Approximately 14-18 g/dL

• For adult females, a quick reminder of normal hemoglobin concentration:

  • Hemoglobin concentration: Approximately 12-16 g/dL

e) Hematocrit

• For adult males, a quick reminder of the normal hematocrit range:

  • Hematocrit range: Approximately 40 - 52%

• For adult females, a quick reminder of the normal hematocrit range:

  • Hematocrit range: Approximately 36 - 48%

g) Cardiac Output

• To calculate the resting cardiac output for a healthy adult at rest:
  • Cardiac output: Approximately 4-5 liters/min

h) Stroke Volume

• To remember the normal stroke volume range for a healthy adult at rest:
  • Stroke volume: Approximately 60 - 70 ml

i) Ejection Fraction

• To recall the normal range of ejection fractions:
  • Normal: Approximately 55 - 75%

j) Blood Viscosity

• To remember the normal blood viscosity range:
  • Blood viscosity: 4 - 5 centipoise (cP)

k) Plasma Osmolality

• To remember the normal plasma osmolality range:
  • Plasma Osmolality: Approximately 280 - 300 mOsm/kg