0:00:06.902,0:00:11.251
At some point between the first and fifth [br]century CE,

0:00:11.251,0:00:18.165
the Hindu sage Patañjali began to codify[br]the ancient, meditative traditions

0:00:18.165,0:00:20.415
practiced throughout India.

0:00:20.415,0:00:25.738
He recorded techniques nearly as old as[br]Indian civilization itself

0:00:25.738,0:00:30.778
in 196 manuals called the Yoga Sutras.

0:00:30.778,0:00:35.957
These texts defined yoga as the ‘yoking’ [br]or restraining of the mind

0:00:35.957,0:00:39.397
from focusing on external objects

0:00:39.397,0:00:43.476
in efforts to reach a state of[br]pure consciousness.

0:00:43.476,0:00:47.598
Over time, yoga came to incorporate[br]physical elements

0:00:47.598,0:00:50.438
from gymnastics and wrestling.

0:00:50.438,0:00:54.258
Today, there are a multitude of approaches[br]to modern yoga –

0:00:54.258,0:01:00.967
though most still maintain the three core[br]elements of Patañjali’s practice:

0:01:00.967,0:01:06.573
physical postures, breathing exercises, [br]and spiritual contemplation.

0:01:06.573,0:01:10.073
This blend of physical and [br]mental exercise

0:01:10.073,0:01:15.095
is widely believed to have a unique [br]set of health advantages.

0:01:15.095,0:01:18.805
Such as improving strength[br]and flexibility,

0:01:18.805,0:01:24.380
boosting heart and lung function, and [br]enhancing psychological well-being.

0:01:24.380,0:01:28.530
But what have contemporary studies shown[br]regarding the benefits

0:01:28.530,0:01:31.120
of this ancient tradition?

0:01:31.120,0:01:33.830
Despite attempts by many researchers,

0:01:33.830,0:01:38.670
it's tough to make specific claims [br]about yoga's advantages.

0:01:38.670,0:01:42.832
Its unique combination of activities makes[br]it difficult to determine

0:01:42.832,0:01:46.832
which component is producing a [br]specific health benefit.

0:01:46.832,0:01:51.436
Additionally, yoga studies are often made [br]up of small sample sizes

0:01:51.436,0:01:52.896
that lack diversity,

0:01:52.896,0:01:58.038
and the heavy reliance on self-reporting[br]makes results subjective.

0:01:58.038,0:02:00.708
However, there are some health benefits

0:02:00.708,0:02:05.448
that have more robust scientific [br]support than others.

0:02:05.448,0:02:08.638
Let’s start with flexibility and strength.

0:02:08.638,0:02:14.168
Twisting your body into yoga’s physical[br]postures stretches multiple muscle groups.

0:02:14.168,0:02:19.279
In the short term, stretching can change[br]the water content of these muscles,

0:02:19.279,0:02:23.373
ligaments, and tendons to make [br]them more elastic.

0:02:23.373,0:02:28.003
Over time, regular stretching [br]stimulates stem cells

0:02:28.003,0:02:31.023
which then differentiate [br]into new muscle tissue

0:02:31.023,0:02:34.933
and other cells that generate [br]elastic collagen.

0:02:34.933,0:02:38.923
Frequent stretching also reduces the[br]body’s natural reflex

0:02:38.923,0:02:40.643
to constrict muscles,

0:02:40.643,0:02:45.077
improving your pain tolerance for feats[br]of flexibility.

0:02:45.077,0:02:48.917
Researchers haven’t found that any one [br]form of yoga

0:02:48.917,0:02:51.437
improves flexibility more than another,

0:02:51.437,0:02:56.039
so the impact of specific [br]postures is unclear.

0:02:56.039,0:02:59.204
But like other low-impact exercises,

0:02:59.204,0:03:05.353
yoga reliably improves fitness and [br]flexibility in healthy populations.

0:03:05.353,0:03:11.364
The practice has also been shown to be[br]a potentially powerful therapeutic tool.

0:03:11.364,0:03:16.995
In studies involving patients with a [br]variety of musculo-skeletal disorders,

0:03:16.995,0:03:21.578
yoga was more helpful at reducing pain and[br]improving mobility

0:03:21.578,0:03:24.818
than other forms of low-impact exercise.

0:03:24.818,0:03:29.308
Adding yoga to an existing exercise [br]routine can improve strength

0:03:29.308,0:03:34.269
and flexibility for hard to treat [br]conditions like chronic lower back pain,

0:03:34.269,0:03:38.455
rheumatoid arthritis, and osteoporosis.

0:03:38.455,0:03:42.877
Yoga’s mix of physical exercise and [br]regimented breathing

0:03:42.877,0:03:46.667
has proven similarly therapeutic [br]for lung health.

0:03:46.667,0:03:51.221
Lung diseases like chronic bronchitis, [br]emphysema, and asthma

0:03:51.221,0:03:54.451
shrink the passageways that carry oxygen,

0:03:54.451,0:03:58.582
while weakening the membrane that [br]brings oxygen into the blood.

0:03:58.582,0:04:02.072
But breathing exercises like those found[br]in yoga

0:04:02.072,0:04:07.569
relax the muscles constricting those[br]passageways and improve oxygen diffusion.

0:04:07.569,0:04:11.933
Increasing the blood’s oxygen content[br]is especially helpful

0:04:11.933,0:04:14.483
for those with weak heart muscles

0:04:14.483,0:04:18.363
who have difficulty pumping[br]enough oxygen throughout the body.

0:04:18.363,0:04:20.163
And for those with healthy hearts,

0:04:20.163,0:04:24.375
this practice can lower blood pressure[br]and reduce risk factors

0:04:24.375,0:04:26.845
for cardiovascular disease.

0:04:26.845,0:04:32.713
Yoga’s most widely celebrated benefit[br]may be the most difficult to prove:

0:04:32.713,0:04:35.143
its psychological effects.

0:04:35.143,0:04:40.545
Despite the longstanding association [br]between yoga and psychological wellbeing,

0:04:40.545,0:04:45.374
there’s little conclusive evidence on [br]how the practice affects mental health.

0:04:45.374,0:04:47.014
One of the biggest claims

0:04:47.014,0:04:52.634
is that yoga improves symptoms of [br]depression and anxiety disorders.

0:04:52.634,0:04:55.854
Since diagnosis of these conditions[br]varies widely

0:04:55.854,0:04:58.794
as do their origin and severity,

0:04:58.794,0:05:02.144
it’s difficult to quantify yoga’s impact.

0:05:02.144,0:05:04.804
However, there is evidence to suggest

0:05:04.804,0:05:08.324
that yoga can help reduce the [br]symptoms of stress,

0:05:08.324,0:05:12.694
as well as meditation or relaxation.

0:05:12.694,0:05:16.224
Research on the effects of [br]yoga is still evolving.

0:05:16.224,0:05:20.994
In the future, we’ll need larger studies, [br]incorporating diverse participants,

0:05:20.994,0:05:24.994
which can measure yoga’s impact[br]on heart attacks, cancer rates,

0:05:24.994,0:05:27.524
cognitive function and more.

0:05:27.524,0:05:31.294
But for now, yoga can continue its [br]ancient tradition

0:05:31.294,0:05:35.524
as a way to exercise, reflect, and relax.