Understanding Resting Metabolic Rate and Energy Expenditure

Resting Metabolic Rate (RMR)

Lowest energy expenditure at rest for physiological functions.

Energy Expenditure

Total energy used by the body over time.

RMR Expression

Measured in kcal/min or kcal/day.

Liver and Brain Contribution

4-5% body weight, 40% of RMR.

Total Daily Energy Expenditure

Sum of RMR, physical activity, and thermic effect.

RMR Percentage

66% of total daily energy expenditure.

Physical Activity Contribution

23% of total daily energy expenditure.

Sedentary Energy Expenditure

300-800 kcals/day for inactive individuals.

Thermic Effect of Food

10% of total ingested calories.

RMR for Males

1.11 to 1.32 kcal/min during activity.

RMR for Females

~0.833 to 1.04 kcal/min during activity.

Optimal Exercise Recommendation

200-400 kcals/day for health benefits.

Moderate Exercise RMR Elevation

Elevates RMR for ~20-30 mins post-exercise.

RMR Increase from Resistance Training

Can increase RMR by ~5% after 9 months.

Factors Influencing RMR

Includes exercise, age, food intake, and testing time.

Age Impact on RMR

RMR decreases with age, especially after 40.

Muscle Loss Rate

3-5% muscle mass loss per decade post-40.

Hormonal Influence on Muscle

Decreased hormones affect muscle anabolism.

Testing Time Influence

RMR varies between morning and afternoon tests.

RMR Testing Procedures

Requires fasting and abstaining from stimulants.

Afternoon RMR Comparison

Afternoon RMR ~100 kcals higher than morning.

Thermic Effect Measurement

Minimal effect on RMR by 4 hours post-meal.

Food Composition Impact

Varies thermic effect based on meal size.

Rest Period

15 minutes of calm, quiet resting required.

Midday Meal

500 ± 200 kcal meal allowed.

Record Intake

Document all food and beverage consumed daily.

Future Tests Timing

Conduct tests within same 4-hour period.

Temperature Range

Maintain temperature between 21-24° Celsius.

Measurement Duration

Temperature measurement lasts at least 15 minutes.

Acclimation Period

Discard first 5 minutes of temperature measurement.

Oxygen Fluctuation

Should be less than 10% during measurement.

RER

Respiratory exchange ratio should be less than 5.

RMR Estimation

Estimates fall within ± 10% of lab values.

Harris-Benedict Equation

Used to estimate basal metabolic rate (BMR).

Basal Metabolic Rate

Typically 5-10% lower than resting metabolic rate.

Activity Level Multiplier

BMR multiplied by activity level for kcal needs.

Contractile Hypertrophy

Increase in dry lean mass and skeletal muscle mass.

Sarcoplasmic Hypertrophy

Increase in skeletal muscle mass and intracellular water.

In-series Hypertrophy

Increase in lean mass with minimal size change.

Standard Error of Estimate

Accuracy estimation of prediction, about 3.5%.

Girth Measurement Correlation

Strong correlation with hydrostatic weighing (r = 0.85-0.90).

2-Girth Method

Used for men, includes neck and mid-abdominal girth.

3-Girth Method

Used for women, includes neck, upper-abdominal, hip girth.

Body Density Calculation

Density = Body Mass / Body Volume.

Underwater Weighing (UWW)

Method to determine body density via water displacement.

Hydration Impact

1-2 kg change affects body fat percentage estimation.

Participant Preparation

Fasting for 3-4 hours recommended before testing.

Hyperhydration status

Increase in body fat percentage (%BF).

Underwater Weighing (UWW)

Method for measuring body composition underwater.

Participant instructions

Change into swimsuit, void bladder and bowels.

Calibration weight

4.08 kg weight used for UWW calibration.

Body Volume (BV)

Volume of air displaced equals body volume.

Air Displacement Plethysmography (ADP)

Measures body volume via air pressure changes.

Boyle's Law

P1ᐧP2 = V2ᐧV1, relates pressure and volume.

SIRI equation

%BF = (495/body density) - 450.

Sources of Error

Factors affecting accuracy of body composition tests.

Fasted state testing

Testing after fasting improves accuracy.

Dehydration effect

Underestimates %BF by 1.1%.

Clothing effects

Wearing clothing can lower %BF measurement.

Isothermal effects

Air trapped in clothing affects body volume.

Body moisture impact

Increases isothermal air, underestimating body volume.

Testing standardization

Consistent conditions improve testing reliability.

Form-fitting apparel

Swimsuits recommended for accurate body measurements.

Food consumption protocols

Avoid calorie-containing foods 4 hours prior.

BOD POD testing

Uses air displacement to measure body composition.

Two-point calibration

Baseline and cylinder calibration for BOD POD.

Testing conditions

Optimal conditions enhance testing accuracy.

Measurement disagreement

More than 150 mL difference requires retest.

Participant motivation

Well-motivated individuals yield better test results.

Testing time consistency

Test at same time for reliable results.

Circadian Rhythms

Biological processes following a 24-hour cycle.

Peak Performance Hours

Optimal performance occurs between 4-8 PM.

Muscle Strength

Maximum force exerted by muscles during contraction.

Tendon Stiffness

Resistance of tendons to deformation under load.

Aerobic Contribution

Energy production through oxygen-dependent pathways.

Training Time Synchronization

Improved performance from training at the same time.

Cold-Water Immersion

Reduces core temperature, affecting performance.

Environmental Temperature Effects

Hot conditions can counteract cold immersion effects.

Active Warm-Up

Increases body temperature before physical activity.

Testing Order

Sequence of fitness tests based on recovery needs.

Resting Tests

Includes anthropometrics, body composition, and flexibility.

Skill-Based Tests

Includes jumps, agility, and sprints.

Maximal Strength Tests

Measures dynamic and isometric strength levels.

Muscular Endurance Tests

Evaluates performance over >10 repetitions.

Anaerobic Testing

Assesses short-duration, high-intensity efforts.

Aerobic Testing

Measures endurance through prolonged exercise.

Gold Standard Equipment

Preferred tools for accurate fitness assessment.

Measurement Error

Variability in results from testing equipment.

Peak Power (PP)

Highest power level achieved in a test.

Mean Power (MP)

Average power output over a specified duration.

Fatigue Index (FI)

Percentage decrease in power from peak to end.

Reliability Coefficient

Consistency of test results across multiple trials.

WAnT Methods

Protocols for Wingate Anaerobic Test execution.

Warm-up

Initial 5-min preparation before cycling test.

RPM

Revolutions per minute; cycling speed measurement.

Peak Power

Maximum power output achieved during the test.

Mean Power

Average power output over the test duration.

Fatigue Index

Percentage indicating performance drop-off over time.

Active Recovery

Low-intensity cycling to aid recovery between sprints.

Cool-down

Post-exercise phase to gradually lower intensity.