Lately there has been a lot of discussion about Yoga and Hinduism. I feel that in order to broaden the base of the these thoughts I should introduce you to a different perspective about yoga.
This perspective is given by Guru Nanak(1469-1539), the first Guru of Sikh religion. Sikh religion is a major religion of India. There have been 10 Gurus of Sikhism. Guru Grantha Sahib is the holy book of Sikhs which for the sikhs (as ordained by the last Guru before his death) is not simply a book but the real living Guru for the Sikhs for all times to come.
I would not go into detail of who Guru Nanak was. You may please follow these links for this purpose:
sikhiwiki.org/index.php/Guru_Nanak
Here I reproduce a shabad(a holy poem) of Guru Nanak on what true yoga is:
First text is in Gurmukhi script and Punjabi language which is followed by english translation
ਸੂਹੀ ਮਹਲਾ ੧ ਘਰੁ ੭
ੴ ਸਤਿਗੁਰ ਪ੍ਰਸਾਦਿ ॥
ਜੋਗੁ ਨ ਖਿੰਥਾ ਜੋਗੁ ਨ ਡੰਡੈ ਜੋਗੁ ਨ ਭਸਮ ਚੜਾਈਐ ॥
ਜੋਗੁ ਨ ਮੁੰਦੀ ਮੂੰਡਿ ਮੁਡਾਇਐ ਜੋਗੁ ਨ ਸਿੰਙੀ ਵਾਈਐ ॥
ਅੰਜਨ ਮਾਹਿ ਨਿਰੰਜਨਿ ਰਹੀਐ ਜੋਗ ਜੁਗਤਿ ਇਵ ਪਾਈਐ ॥੧॥
ਗਲੀ ਜੋਗੁ ਨ ਹੋਈ ॥
ਏਕ ਦ੍ਰਿਸਟਿ ਕਰਿ ਸਮਸਰਿ ਜਾਣੈ ਜੋਗੀ ਕਹੀਐ ਸੋਈ ॥੧॥ ਰਹਾਉ ॥
ਜੋਗੁ ਨ ਬਾਹਰਿ ਮੜੀ ਮਸਾਣੀ ਜੋਗੁ ਨ ਤਾੜੀ ਲਾਈਐ ॥
ਜੋਗੁ ਨ ਦੇਸਿ ਦਿਸੰਤਰਿ ਭਵਿਐ ਜੋਗੁ ਨ ਤੀਰਥਿ ਨਾਈਐ ॥
ਅੰਜਨ ਮਾਹਿ ਨਿਰੰਜਨਿ ਰਹੀਐ ਜੋਗ ਜੁਗਤਿ ਇਵ ਪਾਈਐ ॥੨॥
ਸਤਿਗੁਰੁ ਭੇਟੈ ਤਾ ਸਹਸਾ ਤੂਟੈ ਧਾਵਤੁ ਵਰਜਿ ਰਹਾਈਐ ॥
ਨਿਝਰੁ ਝਰੈ ਸਹਜ ਧੁਨਿ ਲਾਗੈ ਘਰ ਹੀ ਪਰਚਾ ਪਾਈਐ ॥
ਅੰਜਨ ਮਾਹਿ ਨਿਰੰਜਨਿ ਰਹੀਐ ਜੋਗ ਜੁਗਤਿ ਇਵ ਪਾਈਐ ॥੩॥
ਨਾਨਕ ਜੀਵਤਿਆ ਮਰਿ ਰਹੀਐ ਐਸਾ ਜੋਗੁ ਕਮਾਈਐ ॥
ਵਾਜੇ ਬਾਝਹੁ ਸਿੰਙੀ ਵਾਜੈ ਤਉ ਨਿਰਭਉ ਪਦੁ ਪਾਈਐ ॥
ਅੰਜਨ ਮਾਹਿ ਨਿਰੰਜਨਿ ਰਹੀਐ ਜੋਗ ਜੁਗਤਿ ਤਉ ਪਾਈਐ ॥੪॥੧॥੮॥
SOOHEE, FIRST MEHL, SEVENTH HOUSE:
ONE UNIVERSAL CREATOR GOD. BY THE GRACE OF THE TRUE GURU:
Yoga is not the patched coat,
Yoga is not the walking stick.
Yoga is not smearing the body with ashes.
Yoga is not the ear-rings, and not the shaven head.
Yoga is not the blowing of the horn.
Remaining unblemished in the midst of the filth of the world
- this is the way to attain Yoga. || 1 ||
By mere words, Yoga is not attained.
One who looks upon all with a single eye,
and knows them to be one and the same - he alone is known as a Yogi. || 1 || Pause ||
Yoga is not wandering to the tombs of the dead;
Yoga is not sitting in trances.
Yoga is not wandering through foreign lands;
Yoga is not bathing at sacred shrines of pilgrimage.
Remaining unblemished in the midst of the filth of the world - this is the way to attain Yoga. || 2 ||
Meeting with the True Guru, doubt is dispelled, and the wandering mind is restrained.
Nectar rains down, celestial music resounds, and deep within, wisdom is obtained.
Remaining unblemished in the midst of the filth of the world - this is the way to attain Yoga. || 3 ||
O Nanak, remain dead while yet alive - practice such a Yoga.
When the horn is blown without being blown,
then you shall attain the state of fearless dignity.
Remaining unblemished in the midst of the filth of the world - this is the way to attain Yoga. || 4 || 1 || 8 ||
At this point of time I write no more. If a discussion ensues I shall try add more.