How does sugar convert to ATP

Adenosine triphosphate (ATP)

Adenosine triphosphate (ATP) is a molecule that provides energy and is found in every living cell.

Adenosine triphosphate (ATP) usage

Every work and every movement of your body requires energy.

The body uses ATP for this, among other things for the following processes:

Muscle contraction is particularly important in training, but signal transmission through nerves is also important.

The ATP molecule consists of carbon, hydrogen, oxygen and three phosphorus atoms, which form so-called phosphates.

The energy is stored in the chemical bonds of the molecule and is released when a bond is broken and adenosine diphosphate (ADP) is formed.

The muscle cell uses ATP to create tension.

40% of the stored energy is converted into mechanical energy (muscle tension, strength, movement, physical work), while 60% of the energy is lost in the form of heat.

That's why you get warm when you do sports.

Interestingly, this means that our muscles are more efficient than most gasoline engines.

When you contract a muscle, ATP is broken down in all the muscle cells involved:

ATP = ADP + P + energy for muscle contraction (+ heat)

Adenosine triphosphate (ATP) production

ATP is the only source of energy the muscle can use to build tension.

You take in the energy for the ATP molecule from your daily food, which your body either burns directly or it stores it in the fat deopots and glycogen stores for later.

However, the muscle cannot produce fats or carbohydrates directly use it as an energy supplier.

Fats and carbohydrates always have to be broken down in order to produce ATP.

If there is enough oxygen, ...

  • 1 fat molecule in the mitochondria of the muscle cell can be converted to around 129 ATP molecules.
  • 1 glucose molecule (carbohydrate) can be converted into 38 ATP molecules.

ATP that has already been used, which is now in the form of ADP, can - if there is enough creatine phosphate (CP) - be quickly regenerated to ATP:

ADP + CP → ATP + C

Creatine phosphate is a high-energy molecule that is stored in small amounts in muscles. By taking creatine, the creatine stores in the muscles can be optimally filled.

When the creatine stores are full, the energy supply in the muscle is sufficient for about 3-9 seconds of maximum muscle contraction.

If you keep the muscle under tension for longer, fats and carbohydrates are also broken down to build up more ATP molecules:

ADP + P + energy → ATP

If there is enough oxygen (aerobic metabolism), the muscle cell breaks down fat and sugar molecules in the mitochondria.

If there is a lack of oxygen (anaerobic metabolism), the muscles can only convert sugar into ATP. This creates lactate and only 2 ATP molecules per molecule of glucose.

Adenosine triphosphate (ATP) metabolism overview

The following table clarifies the essential metabolic processes for the provision of ATP.

ATP production with:advantagesdisadvantage
Creatine phosphate
  • very fast energy supply
  • only lasts for 10-20 seconds
Glycogen (anaerobic)
  • no oxygen needed
  • immediately runs at full speed
  • Muscle acidified by lactate
  • very inefficient (only 2 ATP)
Glycogen and fat (aerobic)
  • no lactate formation
  • very energy efficient (38-129 ATP)
  • relatively slow energy supply (1-2 minutes)

The aerobic and anerobic energy supply always run at the SAME TIME, only in different proportions depending on the intensity of the exercise.

During maximum physical exertion, your body provides ATP in the following order:

  • In the first 3-9 seconds the ATP and CP stores are emptied. This is the period during which you can develop the most strength.
  • In parallel, the cell begins to make sugar anaerobic convert to ATP. This process reaches its maximum after approx. 40-60 seconds.
  • Aerobic energy production (aerobic glycogen breakdown and fat metabolism) only sets in after about 1-2 minutes Load duration (depending on the degree of load). In the long term, most of the energy can be provided, but this process is comparatively slow.

This also makes it clear why you need several minutes of break between sets in order to regain your strength when doing heavy compound exercises like squats or deadlifts.

Your body needs the breaks in sentences to replenish the ATP stores.

There are two ways in which you can train the process of energy supply in muscles - in addition to strength training:

  1. Cardio trainingin the aerobic area optimizes the energy supply through fats and glycogen.
  2. Creatine monohydrate as a dietary supplement ensures that your muscles always provide sufficient creatine phosphate.

This can alleviate the problem of muscle acidification somewhat:

At a certain lactate level, the enzymes in the cell stop working and no more ATP can be produced.

The muscle cell then stops working completely. We feel this as a “burning sensation” in the muscle during training.

Image source: Wikipedia.