Table 2.

Sedentary behavior frequency, intensity, time, and type principle

Term	Definition	References
Frequency	Refers to the number of SB bouts over a given time frame. The most common SB bout lengths reported in the literature are ≥30 min, ≥60 min, and ≥120 min. Example: interruptions to sitting lasting 2–3 min every 20–30 min seems to yield greater benefits for glycemic control compared to prolonged, uninterrupted sitting. Study design, data analysis, and reporting: include experimental groups with a different frequency of interruptions to SB versus a more sedentary experimental group (control group). If possible, groups should be matched for duration and/or EE. Include detailed description about how participants were instructed about the frequency of interruptions and how adherence to prescribed frequency was assessed. Report changes in the number of daily interruptions to SB and number and duration of prolonged SB bouts.	26–28
Intensity	Refers to any waking behavior with an energy expenditure ≤1.5 MET, while sitting, reclining, or lying down. When focusing at reducing/ interrupting sedentary behavior, intensity refers to the physical activity used to replace sedentary behavior. Example: EE during sitting postures is lower than standing and all intensities of physical activity. Similar responses are observed for oxygen consumption and heart rate. Study design, data analysis, and reporting: include experimental groups with different intensity of interruptions to SB versus a more sedentary experimental group (control group). If possible, groups should be matched for EE. Include detailed description about how participants were instructed about the intensity of interruptions and how adherence to prescribed intensity was assessed. Report changes in objectively measured daily time spent in each physical activity intensity.	5–20
Time	Refers to the total duration of time spent in SB or time spent in bouts of uninterrupted, prolonged sitting (i.e., consecutive min accumulated in SB, usually reported as bouts of ≥30 min, ≥1 h, and ≥2 h of sitting). Example: increasing sedentary time results in maladaptations in physiological systems. In contrast, reducing/interrupting sedentary time results in small benefits. Study design, data analysis, and reporting: include detailed description about how participants were instructed to reduce/interrupt SB (as per other FITT elements) and how adherence to prescribed intervention was assessed. If possible, provide participants with specific and measurable goals, so adherence can be objectively assessed. Report changes in duration of objectively measured total daily SB and prolonged SB bouts.	29–33
Type	Refers to the main intention of the SB and the context in which it occurs. Example: SB associated with energy surplus is more detrimental than exposures to sedentary behavior in energy balance. Study design, data analysis, and reporting: measure participation in each type of SB using a validated questionnaire or diary. Similarly, record types of physical activity that can be used to reduce/interrupt SB. If appropriate, design the intervention to tackle specific type/context of SB (e.g., work-related, recreational screen time, etc.) and standardize the FITT of physical activities being used to reduce/interrupt SB. Report changes in duration of objectively measured total daily SB and prolonged SB bouts, and self-reported duration in each specific type/context of SB.	34, 35

EE, energy expenditure; FITT, frequency, intensity, time, and type principle; MET, metabolic equivalent; SB, sedentary behavior.