A calorie is a unit used to measure energy, specifically the energy the body derives from food. For people who spend much of their day seated, understanding the minimum number of calories required just to keep the body running is the first step in determining daily energy expenditure. The body constantly burns energy, even when completely still, a process often underestimated in a sedentary lifestyle.
Calculating Your Minimum Energy Burn
The most accurate measure of the minimum energy the body needs for basic survival is the Basal Metabolic Rate (BMR). BMR represents the calories burned to power essential involuntary functions like breathing, circulating blood, and cell production. This accounts for the largest portion of a person’s total daily energy expenditure, typically ranging from 60 to 70 percent of total calories burned.
A closely related measure is the Resting Metabolic Rate (RMR), which is the energy spent while at rest. RMR is generally about 10 percent higher than BMR and serves as the most practical baseline estimate for someone spending an entire day sitting. Predictive equations are used to estimate this baseline and rely on measurable variables.
These predictive formulas incorporate a person’s age, biological sex, height, and total body weight to provide a calculated minimum energy burn. Males tend to have a higher BMR than females due to a greater average proportion of lean muscle mass. Muscle tissue requires more energy to maintain at rest compared to fat tissue, making body composition a significant factor in this baseline number.
The Role of Non-Exercise Activity Thermogenesis (NEAT)
Total daily energy expenditure includes BMR, energy used for eating, and physical movement. Non-Exercise Activity Thermogenesis (NEAT) is the energy expended for all physical activities other than sleeping, eating, or structured exercise. NEAT includes standing, walking, shifting posture, and fidgeting.
While BMR is relatively constant, NEAT is highly variable among individuals and accounts for a significant difference in total calories burned daily. Prolonged sitting drastically minimizes this component of energy expenditure, keeping a person’s total burn close to their RMR baseline.
Sedentary jobs are associated with lower overall daily calorie burn due to low NEAT. Simply standing instead of sitting can increase the hourly calorie burn by a measurable amount, demonstrating the impact of slight changes in posture. When a person is seated all day, minimal movements like reaching or typing represent the entirety of their NEAT contribution.
Boosting Calorie Burn While Remaining Seated
Individuals required to remain seated for long periods can strategically incorporate micro-movements to raise their overall energy expenditure above the baseline RMR.
Increase Fidgeting
One effective strategy is to increase fidgeting, such as tapping your feet, shifting your weight, or drumming your fingers. This type of non-exercise movement can contribute extra calories burned throughout the day.
Improve Posture
Focusing on proper posture while seated can engage supporting musculature, requiring more energy than slouching. Actively maintaining an upright position engages the core and back muscles, creating slight muscle tension that increases caloric output. Replacing a standard office chair with an exercise ball or a dynamic seating option requires constant, subtle adjustments from the core muscles to maintain balance.
Perform Seated Exercises
Specific exercises can be performed without leaving the chair, utilizing isometric contractions and small movements. Repeatedly squeezing the gluteal or abdominal muscles for several seconds engages large muscle groups in the torso. Seated leg raises, where one or both legs are extended and held parallel to the floor, actively work the quadriceps and core muscles under the desk.