“Seat Hours”, Conscious Movement, Adrenaline
Sedentary behavior is defined as any activity with low energy expenditure that we perform while awake; it includes sitting or lying down, and is considered the largest component of human movement patterns, which is detrimental to health and, in adults and older people, can account for between 5 and 11 hours/day (Pinto et al., 2023). It has become a subject of study over the past 20 years, aiming to help guide public health initiatives and clinical practice, moving beyond the message of “more exercise” toward more effective and comprehensive campaigns based on phrases like “sit less, move more, and exercise” (Pinto et al., 2023).
Scientific consensus is clear: reducing daily steps for just 14 days can lead to approximately 500 g of lean mass loss and a 7% increase in abdominal fat, even if total body fat does not visibly increase. After 20 days of sedentary behavior, body composition begins to change. Conversely, reducing sedentary behavior by at least 30 minutes per day over more than two weeks—for example, standing an extra 1.3 hours/day—may not alter weight or body measurements, but can still improve body fat percentage.
More sedentary behavior, increasing the number of “sitting hours/day,” reduces the total calories we need to function; it seems obvious and common sense, but when it comes to the amount of calories needed to “function normally” (breathe, think, blink, digest, etc.) and remain functional, all the sugar we consume adds up and increases the daily calories that will be stored as fat. In addition, if sitting hours increase (vs. hours standing, using stairs, or walking the dog), and we need less energy to function, appetite does not decrease (Pinto et al., 2023), and that is where problems begin with body fat produced by excess calories from sugars, fats, and food in general.
How does a sedentary body use sugar?
We could say that the scientific explanation is: the more hours spent sitting, the more the body becomes resistant to insulin; that is, sensitivity is lost, making insulin less functional for metabolism. Since less energy is needed to remain functional, the cells “lock” the door insulin uses, but the pancreas continues producing it in response to any olfactory, visual, or auditory stimulus, as we have already explained in other publications. It can be said, then, that the hours of the day we spend sitting, reclining, or lying down are a risk factor for developing glucose and sugar intolerance, incorrectly referred to as prediabetes, and also promote the formation of body fat, mainly from sugar.
However, many ways have been proposed to measure the impact of whether meals include carbohydrates, with or without free sugars, and their immediate effect on the body; in this sense, the perception of well-being is an indirect and subjective form that can be measured and thus converted into specific measurements. When it comes to measuring the effect of nutrients in meals (the ratio between proteins, fats, starches, and sugars) among sedentary people (more than 9 sitting hours/day) or those who take active breaks, in the 4h after eating, no difference was found in terms of learning or attention skills and blood circulation related to the composition of meals in the short term. However, active breaks improve the perception of sleep quality, mood, and reduced insulin levels. But perhaps most importantly, the composition of the diet does not have as much influence on the perception of well-being compared to taking active breaks—fewer sitting hours—understanding the perception of well-being as sleep quality, learning/attention, mood, and overall metabolic and circulatory health (Wanders et al., 2021)..
Adrenaline… The survival hormone
In response to physical and emotional stress, adrenaline is released into the blood; it is responsible for activating the mechanisms that use the fat stored in the body (Zhang et al., 2022) to produce energy in the form of glucose, increasing blood sugar levels and giving us more available energy. It is one more hormone we need in order to function automatically or in emergencies, because it improves insulin sensitivity in the tissues without making the pancreas work harder; in other words, it regulates the glucose-insulin relationship because, by producing sugars from the body’s fat reserves, the cells know they do not come from food and use them differently. Adrenaline directly influences the muscle’s ability to absorb and process these sugars; therefore, exercise aimed at gaining muscle mass is a powerful way to stimulate the natural function of adrenaline (Yang, Li, Haller, Schatz, & Rong, 2022) and the hormonal regulation needed to maintain a healthy metabolic balance.
It is different to talk about sedentary behavior and physical inactivity. There are guidelines on the time and intensity we should dedicate to practicing a sport to know how many extra calories we are “burning”; however, it is possible to practice sports intensely and have sedentary behavior at the same time, because this refers to the time we remain sitting, lying down, or reclining, and there is little information available about the role this behavior plays, for example, an 8h/day office workday, in the predisposition to obesity and the risk of death (Bourdier, Simon, Bessesen, Blanc, & Bergouignan, 2023).
Consuming sugar means making the decision to move, to reduce “sitting hours” and combine the pleasure of sweetening with the pleasure of a flexible, strong, and stable body that uses all the energy we get from food. Reducing or interrupting sedentary behavior, even for a short time, improves blood sugar levels after a meal and the amount of insulin produced by the pancreas, and improves blood pressure levels and leg circulation as we age. If reducing sedentary behavior becomes a long-term habit, it helps control body weight, reduce waist circumference, body fat percentage, and blood sugar levels upon waking or during long periods of fasting, among other important effects (Pinto et al., 2023).
This is precision medicine, which uses mathematical models to explain diabetes and how everything from emotions to hormones and blood sugar requires a detailed view of metabolic balance, with the aim of delaying the onset of chronic diseases or, where applicable, developing more precise drugs (Yang, Li, Haller, Schatz, & Rong, 2022).
