The third Niyama is tapas. The literal translation of this Sanskrit word is fire or heat. The interpretation, in the context of the Yoga Sutras (an authoritative ancient text on yoga, filled with aphorisms outlining the eight limbs of yoga), is self-discipline… dedication… or a fiery determination. Because the aim of a traditional yoga practice is Supreme Awareness - the fiery determination we are talking about here is in relation to elevating awareness.
This aim takes tapas far beyond your yoga mat and into every part of your life. Tapas could be the self-disciplined repetition of a loving-kindness mantra every morning when you wake up. Tapas could look like a dedication to paying attention on purpose when you are listening to your children or husband. Tapas could also be the fiery determination it takes to commit to a regular meditation practice. What does your tapas look like? Take some time this month to ask and test out some possible answers to this question.
One consideration, as you explore, remember that each of the yamas and niyamas contain all of the others. For example when you practice the third niyama, tapas - the first yama, ahimsa (non-violence) is also meant to be there. This keeps our tapas practice dedicated and determined without crossing over into rigid and punishing.