For years there has been a running -- and most likely never to be resolved -- debate about what yoga truly is. Generally, the widest polarity in this debate is between the traditionalists (sometimes referred to, somewhat pejoratively as "purists") who accept, believe, and attempt to practice as the particular lineage they have dedicated themselves to promulgates, and perhaps the contemporary majority view that "Yoga is what I (we) say it is." For this latter camp, yoga often tends to be more physically oriented and even approached as a 'workout.'
I'm actually not very much interested in this debate. My own path began with reading about Buddhism and Yoga philosophy while still in High School. I then began a yoga practice (which at the time meant asana practice with some side-acknowledgement to meditation) and then finally my beginning to practice Buddhist meditation within six months of taking my first yoga class. This was back in 1976. I have been teaching yoga since 1995, and was ordained as a Dharma Teacher in 2007.
Years ago, Rodney Yee was asked in an interview if he had begun to practice yoga "before beginning to practice meditation" and his response was the rather anemic, "In some ways yoga is meditation." I say this is an anemic response because it is a historical fact that for most of its history, yoga was meditation; meditation was yoga! When Gotama left his home to become a yogi, he wasn't doing Sun Salutations by the side of the river; he was sitting in meditation, learning from teachers the system of yoga later collated in The Yoga-Sutra by Patanjali.
The earliest use of the word yoga was often metaphorically as the yoking of mind and body via the breath which we may recognize as the description of meditation. Patanjali's Yoga-Sutra is a concise template for yoga practice as then understood. So this is where the 'purists' get it right: the essential core of yogic practice is meditation.
However, the Buddha, a consummate yogi, in teaching satipatthana (the four applications for mindfulness: body, feelings, mind, dhammas) offered a yoga practice that can indeed be practiced while doing almost anything. By turning his attention to his body, his feelings and emotions, as well as how his experience responds to the environment, he made the yogic practice of mindfulness something that can be practiced while sitting, lying down, walking and standing; but also while cooking, eating, shitting, changing diapers, folding laundry etc. etc. In this way, contemporary practitioners who say "yoga is what I say it is" or "it's all yoga" can be right. But only when what is being done is being approached as mindfulness practice.
Thus, if one practices the asanas of modern hatha-yoga (whatever style, with or without goats; with or without clothing; with or without jump-backs) without the foundation of meditative mindfulness, it may be exercise, and it may be fun, but it is not yet yoga. What makes whatever we do yoga is the state of the mind one is in while doing what it is we do.
It is this understanding that is behind the micro-practices I've written about elsewhere in this blog. With this orientation of mindfulness brought to our daily activities, we can practice yoga everyday and in almost any situation we find ourselves in.