At Zone 2, mitochondria are at metabolic equilibrium and at the highest operating capacity. This is why it is a challenging intensity for well-trained athletes (it must be).
Lactate is being produced at a meaningful rate as glycolytic rate is moderate, but the mitochondrial lactate oxidation complex (mLOC) is clearing it at the same rate, converting it back to pyruvate and feeding it directly into oxidative phosphorylation. The lactate shuttle, both within and between cells and tissues, is running at full capacity.
Fat oxidation is at its peak. The NAD⁺/NADH ratio is stable, reflecting a healthy redox environment in which glycolysis and mitochondrial processing remain tightly coupled. The system is maximally stimulated while still in balance.
This is precisely why Zone 2 is probably one of the most powerful sustained training stimulus for mitochondrial adaptation. Mitochondrial biogenesis requires that the organelle be pushed close to its capacity. Zone 2 does that, while keeping the internal environment stable enough that the stimulus can be sustained for a prolonged period and recovered from it efficiently.
-And with all this said, high intensity training is absolutely key for performance.
https://t.co/CWkZyRnJKl
Sigue aquí nuestro Minuto a Minuto del Giro de Italia, por la página web de Ciclismo Internacional.
Conectado con @BiciGoga, @jhonjaimeosorio y Santiago Botero en el #ElGiroPorCaracol
https://t.co/TGroVUebKV
Se puede opinar lo que sea de @decathloncmacgm y la decisión de llevar a @seixas_paul a @LeTour.
Lo que no se puede negar es lo emotivo del video de anuncio 👏🏾👏🏾👏🏾
🎥@decathloncmacgm https://t.co/i0FgiVtS1L
🇫🇷 #ParisNice - ❌ @ivanromeo_03 no tomará la salida en la etapa de hoy tras haber pasado una mala noche con molestias estomacales.
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Iván Romeo will not start today’s stage after having had a bad night with stomach discomfort.
#RodamosJuntos I @movistar_es
I @ParisNice
« Il a réalisé un travail formidable, nous l'avons recruté pour ça »: Bruno Armirail, nouveau coéquipier modèle de Jonas Vingegaard
➡️ https://t.co/clkAkxjnHS
Domen Novak waarschuwt Paul Seixas: “Pogacar won zijn eerste Tour terwijl hij pizza at en bier dronk”
https://t.co/MdAZZdPKbv
🇸🇮 #wielrennen#koers#cycling
Esta es la situación de carrera en la prueba masculina de los #NacionalesRuta2026:
El número 31 está en la fuga y cabeza de carrera, seguido del un lote que lo persigue a 55 segundos y luego está el grupo principal que viene a 2:35.
#UCI#Colombia