“10 minutes a day, 1 hour if you’re in a hurry” said the wise man! Yes, because the important thing is not when or what we practice but how.
Indeed, the practice of yoga allows, among other, the secretion of GABA, the hormone of stress resilience. But this production stops, and the rate drops gradually, as soon as the practice stops.
So we need our daily dose! The duration of the practice is thus less important than its regularity. Short daily practices are hence more efficient than a weekly practice of 1h30, in the current state of discovery of neurosciences.
In my yogic sense, it is therefore better to allow us a few minutes of authentic practice in mindfulness everyday, than an hour a week making the grocery list or repeating the day in our head on the mat.
The library of our meditations is enriched regularly on iTunes and Youtube, so do not hesitate to repeat some practices on a daily basis!