Classical yoga, haṭha, and modern practice — keep text and gym apart.
Yoga Sūtra and haṭha texts.
https://www.sanskritdocuments.org/doc_yoga/
Scholarly e-text.
https://gretil.sub.uni-goettingen.de/gretil.html
Older English.
https://www.sacred-texts.com/hin/yogasutr.htm
Clinical literature, not doctrine.
https://www.ncbi.nlm.nih.gov/pmc/?term=yoga
Named translators only.
https://archive.org/details/yogasutra