Anaerobic activity occurs when we express short bursts of energy. Also we are accessing the fast twitch muscle fibers. We can always do more than our ego mind says we can. Be prepared to work up a mild sweat. Any posture can be amplified with a more vigorous pranayama. Just increase the volume expressed on your inhale and exhale. As you breathe more forcefully you will turn on the juice!
Follow my instruction cues and always listen to your own body first. I may have worked this kriya many times and can go deeper in the asanas. This may be your first time. Let your body guide you.
And if you are on your Moon/Menstrual cycle or pregnant please substitute any held breath with long-deep breathing.