I often wondered why anaerobic and aerobic exercises are named as they are. Surely, while running, you should not be out of breath to avoid “switching to anaerobic metabolism”. But why is it called anaerobic metabolism when doing short bursts of weight training even though I am barely out of breath? Recently, I refreshed my biology class 11 knowledge with the help of wikipedia and want to share my findings.
Adenosine Triphosphate (ATP)
To make a muscle work it needs energy, which is primarily generated by ATP splitting a Phosphat MOlecule and changing to Adenosindriphosphat, in the process releasing energy. However, this energy is only short lived, and we only have a very limited amount of ATP readily available in our muscle cells, which would only amount to at max 3s of muscle contraction. To provide a constant stream of energy, ATP needs to resynthesized by means of other energy storage mediums suhc as glykogen and fats, which are not always directly stored in the muscle cells.
ATP + H2O → ADP + P + Energie
wikipedia bild
Aerobic Metabolism
Aerob means, that this kind of metabolismn is done under use of oxygen. Although these proceses generate a lot of ATP, they take several sub steps which consequently delays the energy provision time.
aerob-glykolytic
Glycogen is metabolised in glycolyse process step to pyruvat in cell plasma. If there is oxygen available the mitochondria can do oxidative decarboxylase which transforms pyruvat into a sub product called Acetyl-CoA thereby already splitting a CO2 molecule. In the final citrat cycle Acetyl-CoA is completely metabolised to generate ATP.
for this whole process we can simplify it to
Traubenzucker + Sauerstoff → Wasser + Kohlendioxid + Energie
aerob-lipolytic
Fette bestehen au slangkettige Kohlenwasserstoffe, die bei Bedarf in den Mitochondrien im Prozess β-Oxidation stufenweise zerlegt werden.
Am Ende entsteht Acetyl-CoA, das – wie aus Glukose – im Citratzyklus weiterverarbeitet wird, um Energie (ATP) zu gewinnen.
Fett + Sauerstoff → Wasser + Kohlendioxid + Energie
Anaerobic Metabolism
Anaerob Metabolism just means, it is done without the use of oxygen. It’s fast but produces limited energy. This process can be split in two categories anaerob-alactazid, therefore producing no lactat as byproduct and anaerob-lactacide, producing lactat as byproduct.
anaerob-alactazid – Phosphat metabolism
After the short burts of the limited amount of ATP located in the muscle cells, Creatine Phosphat, which also is located in the muscle cells can be used to shortly resynthesize ATP
ADP + Creatine Phosphate → ATP + Creatine
Anaerob lactacid
As a last resort, the limited amount of Glykogen stored in muscle cells can also be metobalised into Pyruvat thereby releasing ATP (see aerob glykolyse). To further provide energy, Pyruvat can further be anaerobically metabolised into lactat to generate some more energy.
kann im zellplasma stattfinden
lactat erzeugung => lactat threshold
Lactate = a byproduct of fast, oxygen-limited energy production
The fatigue comes from hydrogen ions (H⁺) that are released alongside lactate.
- ese lower your muscle pH (more acidic).
- This interferes with:
- Muscle contraction
- Calcium release
- Nerve signaling
it makes lactate when it needs anaerobic energy, usually because oxygen delivery is maxed out or too slow
You build the engine with Zone 2,
You upgrade the fuel system with threshold work,
You push the RPM limit with VO₂ max intervals.
| Capacity | Meaning | How You Train It | Zone |
|---|---|---|---|
| Aerobic preference | Use oxygen longer, burn fat, spare carbs | Zone 2, long easy runs | Zone 2 |
| Lactate clearance | Recycle/remove lactate & buffer acidity | Threshold/tempo runs | Zone 3/4 |
| Peak oxygen delivery (VO₂) | Use the most oxygen possible at max work | VO₂ max intervals | Zone 5 |
Training Implications
Weight Training: Primarily involves anaerobic metabolism due to the need for quick energy bursts during short, intense efforts. The body relies on ATP and creatine phosphate for immediate energy. Supplementing with creatine can enhance the storage of creatine phosphate in muscle cells allowing for a greater reserve of quick energy. A side effect is that the high concentration of creatine in the muscle cells draws water into the cells through osmosis.
Cardio Training: Relies heavily on aerobic metabolism. Activities like running, swimming, or cycling demand sustained energy over a prolonged period, making efficient use of oxygen to convert carbohydrates and fats into ATP. The process of utilizing fats as an energy source typically starts after around 20 minutes of exercise.
