Books like The Heart of Yoga
T. K. V. Desikachar
The Heart of Yoga is 272 pages, about 4 hours 59 minutes at 250 words a minute.
12 books to read next
How long each takes
Light on Yoga 7.7 h 
The Complete Yoga Book 10.1 h 
Yoga 3.8 h 
Yoga 7.9 h 
Iyengar Yoga for Motherhood 9.4 h 
Yoga Anatomy 6.0 h 
Light on Prāṇāyāma 5.4 h 
Acu-Yoga 4.5 h 
Yoga Therapy 4.4 h 
Science of Breath 2.6 h 
Hatha Yoga 3.2 h 
Yoga 5.7 h Bar height shows length. Estimated at 250 words a minute.