Polarized or threshold training: is there a superior training intensity distribution to improve V̇O2max, endurance capacity and mitochondrial function? A study in Wistar Rat models

• DOI: 10.1007/s13105-025-01079-6
• Publication Date: 2025-04-04T09:01:37Z
• Authors: Pedro Oliveira; Miguel Anjos; Ariane Flores; Francisco Peixoto; Ana Isabel Padrão; Hélder Fonseca
• Keywords: MFN2; Endurance Training; TFAM; Treadmill

Conflicting evidence exists regarding the superiority of Polarized Training (POL) vs other training intensity distribution models. Compare POL threshold (THR) on V̇O2max, endurance capacity (EC) and mitochondrial function. Fifteen male Wistar rats (336.1 ± 30.4 g) were divided in: (n = 5), THR 5) or control (CON; n groups. V̇O2max (indirect calorimetry) EC (treadmill exhaustion test) determined at baseline four eight-weeks training. consisted 80% running volume 60%V̇O2max 20% 90%V̇O2max while trained only 75%V̇O2max. Both protocols isocaloric performed 5d/week. All animals housed in cages with access to wheel allow ad libitum activity. After training, sacrificed left ventricle (LV) myocardium, diaphragm, tibialis anterior soleus muscles collected for high-resolution respirometry, biochemical histological analysis. There no differences between similar even though was higher compared CON. there also significant OXPHOS any major function markers assessed tissues analyzed. The expression MFN1, MFN2, PGC-1α, TFAM, DRP1, OPA1 TOM20 as well activity citrate synthase all tissues. performance bioenergetic after