This is what your “yoga is anything I want it to be” has done, kiss your sweet results goodbye!
The following Medical Research (at the bottom) is published in a peer journal. Also it is published on Pub Med.
If you pick up any copy of Hatha Yoga Pradipika you will see the following 4 chapters have the requirements for being a yogi, instruction on asanas, what prana is, diet restrictions, pranayama, kriyas, mudras, bandhas, samadhi and nada. Why would anyone after just looking at the contents think that a 30 minute hatha yoga video has much to do with Hatha Yoga at all? This is the problem.
Think about this for a second. Asana being about balancing prana only, not western exercise and raising heart rate and getting a work out. This opens the tissues and reduces stress hormones, cortisol, adrenaline, and makes the system function easier and healthier in all ways. Pranayama is going to purify the tissues and blood bringing the cardiovascular health that they are testing the absolute wrong part of the practice for. This is just due to the lack of knowlege of waht yoga is due to the lack of proper education. i.e. 200 or 500 hr teachers trainings. With the tissues not stressed by western exercise induced stress, the heart does not need to work as hard and the cardiovascular system is strengthened thusly by two methods.
It is not brain surgery or jet propulsion theory and if you are a hammer, everything is a nail or if you only know one thing you cannot see beyond it.
This is all the same idea when they do research on what the modern world thinks ghee is. Tell ya what, your not gonna have the lack of results as when using the real McCoy. Ever.
The metabolic cost of hatha yoga.
To determine the metabolic and heart rate (HR) responses of hatha yoga, 26 women (19-40 years old) performed a 30-minute hatha yoga routine of supine lying, sitting, and standing asanas (i.e., postures). Subjects followed identical videotaped sequences of hatha yoga asanas. Mean physiological responses were compared to the physiological responses of resting in a chair and walking on a treadmill at 93.86 m.min(-1) [3.5 miles per hour (mph)]. During the 30-minute hatha yoga routine, mean absolute oxygen consumption (Vo(2)), relative Vo(2), percentage maximal oxygen consumption (%Vo(2)R), metabolic equivalents (METs), energy expenditure, HR, and percentage maximal heart rate (%MHR) were 0.45 L.min(-1), 7.59 ml.kg(-1).min(-1), 14.50%, 2.17 METs, 2.23 kcal.min(-1), 105.29 b.min(-1), and 56.89%, respectively. When compared to resting in a chair, hatha yoga required 114% greater O(2) (L.min(-1)), 111% greater O(2)(ml.kg(-1).min(-1)), 4,294% greater %Vo(2)R, 111% greater METs, 108% greater kcal.min(-1), 24% greater HR, and 24% greater %MHR. When compared to walking at 93.86 m.min(-1), hatha yoga required 54% lower O(2)(L.min(-1)), 53% lower O(2)(ml.kg(-1).min(-1)), 68% lower %Vo(2)R, 53% lower METs, 53% lower kcal.min(-1), 21% lower HR, and 21% lower %MHR. The hatha yoga routine in this study required 14.50% Vo(2)R, which can be considered a very light intensity and significantly lighter than 44.8% Vo(2)R for walking at 93.86 m.min(-1) (3.5 mph). The intensity of hatha yoga may be too low to provide a training stimulus for improving cardiovascular fitness. Although previous research suggests that hatha yoga is an acceptable form of physical activity for enhancing muscular fitness and flexibility, these data demonstrate that hatha yoga may have little, if any, cardiovascular benefit.