Exercising on an empty stomach - an evolutionary view of exercise

How does training on an empty stomach work and what happens in the body?

In order to have energy available in the morning, we have an endogenous system - our biorhythm. This is a genetically controlled 24-hour rhythm that serves as a kind of „clock“ for the activity of every organ and every cell ^[1]. This clock activates our stress hormone axis ^[2], which, by releasing cortisol, ensures that we wake up and also sets our motor system in motion. This is also known as the cortisol awakening response (CAR). ^[4] Cortisol controls many metabolic processes: For example, the formation of new energy in the form of glucose in the liver, the increase in cerebral blood flow and energy supply in the brain and muscles as well as the regulation of the immune system ^[5]. The body therefore physiologically supplies itself with energy. It therefore does not initially need any food from outside.

What happens during nutrition training

Working out on an empty stomach consumes energy - among other things in the form of sugar. This means that less sugar is available for our cells. This also means that less energy can be produced there in the form of ATP (universal energy carrier in the body). The cell registers the lack of energy with the so-called enzyme AMPK (AMP-activated protein kinase). This ensures that more ATP is produced from the reduced amount of sugar: A kind of „Öconomization of the energy balance“ therefore takes place ^[6].

In order for this process to work:

1. More mitochondria (power plants of the cells) must be formed to increase oxygen-dependent energy production. ^[7]
2. New sugar transporters are formed that improve the uptake of sugar from the bloodstream into the cell. [13]

Both processes are caused by AMPK, so that after some time of internal training, sugar can be absorbed more easily and processed into a lot of ATP in the new mitochondria. Overall, this optimizes energy production and fat acids are dissolved from the body's own reserves fat cells and processed into ATP. The cells become more sensitive to insulin again and the sugar balance is optimized.

These mechanisms are massively reduced when carbohydrates are consumed or an extensive breakfast is eaten before or during sporting activity. ^[8

Movement on a sober stomach – Our evolutionary perspective

For our ancestors, when it came to food intake, the rule was: first move, then eat. This system dates back to a time in evolution when the constant availability of food - especially in the morning - was not possible without prior gathering or hunting. Homo sapiens therefore had to be fit enough to draw on their reserves and be motivated to move even on an empty stomach in order not to starve. This system is anchored in our genes and is regulated by hormones and nerves via complex mechanisms. The neurotransmitter dopamine plays an important role in this. Among other things, it is responsible for our curiosity and is also released when we are hungry, which in turn motivates us to exercise ^[9].

The best methods and tips for parent training

Exercising on an empty stomach offers various benefits, such as an increased fat burning^[10] or a better use of energy. So to speak, a „Öconomization of the metabolism“ ^[11]. Incidentally, this also applies to intermittent fasting in general. Both intermittent fasting and regular exercise help to optimize our body composition^[12].

The “disadvantage”: The positive effects of night-time exercise are not immediate. Performance is also unlikely to be achieved immediately. So don't go from „0 to 100“ the first time. Because being hungry and feeling hungry also mean stress for the body, i.e. increased cortisol release. Although this can be compensated for by exercise, it should not be exaggerated, especially in the early stages. We therefore recommend moderate endurance units and a slow approach to exercise. In preparation, you can fast intermittently, preferably overnight, without exertion (16 hours for men, 10-12 hours is also sufficient for women). In the morning, start with light, short units and gradually increase to longer, moderate endurance units (e.g. running or cycling)

Nuechtern-trainieren – Geheimtipp für die Fettverbrennung?

Exercising on an empty stomach also boosts your metabolism. Exercising on an empty stomach reduces the amount of sugar in the bloodstream and automatically optimizes the body's energy supply. This is because if the required energy cannot be obtained from food, the body automatically draws on its own reserves, which has a positive effect on reducing the body fat percentage.

At the same time, our organism begins to counteract future deficiency situations and adapt: A mechanism is triggered in the cells by the resulting energy deficiency, which improves glucose uptake. This means that we become more insulin-sensitive and new mitochondria are formed. In the future, we will be able to produce as much energy as possible in the form of ATP with just a few energy sources.