The word yoga means <union>. In relation to Sikh Dharma, this means, ultimately, union of the human consciousness with Wahe Guru. In addition, one might reflect on 4 specific documents in order to become more aware of the intrinsic relationship between Yoga and Sikh Dharma. They are:
1) Guru Nanak's work entitled <Siddh Gosht>. From beginning to end, Siddh Gosht is about the practice of ultimate yoga. It rewards deep study and reflection. Too lengthy to cite in detail here, one of Guru Nanak's concluding passages is this--
<O yogis, this is the essence of the Word:
<Without the Name of the Lord there is no yoga;
<Those who drink of the Name are intoxicated day and night.
<He alone realizes the bliss who ever lives in the Name.
<All things are born out of the Name -- all wisdom comes through the Name.
<One may wear many costumes,
<But without the Name one is led away from the path, as the Lord wills.
<The Name and the way of yoga are found through the True Guru.
<Consider this, and you will see that without the Name, one is not liberated.
<Oh my Lord, your glory is known only to you; what can anyone say?
2) The Shabad from Gurbani Kirtan, known as <Raj Jog Takht Dheean, Guru Ram Das>. This Shabad explains the mastery of Guru Ram Das over the realm of Raj (meditation) Yoga. It explains the capacity of Guru Ram Das to bless the seeker with bliss and the vision of Wahe Guru.
3) A Shabad written by Guru Gobind Singh, known as <Reh Man, Eh Bid Jog Man Chao>. This Shabad details the instructions on how one should prepare the mind in order to merge with the infinite.
4) The passage of Guru Gobind Singh's <Bachitar Natak> (from <Dasam Granth>), in which Guru Gobind Singh describes his own (immediately) previous lifetime in which he prepared and perfected himself by his meditations on Wahe Guruji, as a yoga siddha known as Rishi Dushtamon, at Hemkhunt Sahib. That passage is as follows:
<Now I relate my own story:
<How Wahe Guru ji sent me into this world
<while I was undergoing penance (in order to please Wahe Guru)
<on the mountain of Hemkunt, at a place called Sapt Sringa
<(the range of the seven peaks)
<where King Pandu had also done penance.
<I went through various penances,
<and meditated so much on Mahakala
<(the all-powerful, Infinite Wisdom of Wahe Guru),
<that I became one with Wahe Guru.
<This same Incomprehensible One was also worshipped
<by my father (9th Guru) and mother
<who had imbibed Wahe Guru's discipline in many ways
<to become one with Wahe Guru.
<Wahe Guru was extremely pleased with their devotion
<and ordered me to be born into this Dark Age.
<It was not my desire to take birth,
<for my mind was fixed on the feet of Wahe Guru,
<but Wahe Guru remonstrated with me with great earnestness.
--Bachitar Natak, Guru Gobind Singh
These 4 documents in themselves reveal 2 things: the essence of spritual practice called yoga which the Gurus themselves prioritized, and therefore, the intrinsic place which yoga has within the context of Sikh Dharma. If the concept of yoga is understood in this light, as union with Wahe Guru, then obviously the entire Siri Guru Granth Sahib is only about true yoga. Additionally, within the historical traditions of yoga there are many, many teachings on diet, meditation and physical exercise which promote health, fitness, personal strength and well being. If one is to serve the Guru's wish and command in the world of stress and suffering, such personal health, strength and well-being are a necessity. It is in this light alone that we, as Sikhs of the Guru, practice yoga and meditation as support for our faith and devotion to the Guru. Kundalini Yoga is the mother science which combines all the yogas. Don't we all, as Sikhs, deserve to be blessed by the best and with everything?
May His wisdom and compassion bring the blessing and vision of true understanding.