Here is a video clip titled "The Health Benefits of Yoga" broadcast on ABC’s Good Morning America TV Show. There is a segment with Sat Bir Singh Khalsa, Ph.D. where he talks about the scientific studies done which shows the benefits of doing Yoga.
Whenever I hear Sikhs ragging on Yoga saying it is "against Sikhi" I can only laugh at the ignorance and lack of understanding of Yoga. Some of this opinion seems to be from the perception that Yoga = Hinduism. There is a strong will to want to dis-associate from anything Hindu-ish. I can understand where this comes from with all the things that have gone on in India in the past 50 years, but in fact, Yoga is not a religion and is not a Hindu practice.
The other mis-understanding relating to Yoga is that "the Gurus were against Yoga". In case you didn’t know Yoga means "Union" (to Yoke or Unite) and this "Yoga" can come in so many forms. We as Sikhs practice many types of "Yogas" if you look at it from this perspective.
People often mention to me various parts of Gurbani (Sidh Gosht and others ) as an indication of the Guru’s being against Yoga. When in reality if you look at the big picture of the circumstance and the examples shown, the lessons are more about the not leaving society to seek God, and how it is fruitless trying to seek "super natural powers". Anything in life that might have benefits, when out of balance can be bad. The inbalance is the issue…not the normally the thing itself.
I think it is time that Sikhs open their minds a bit and stop being so judgmental about something they know little about. In my experience Kundalini Yoga helps create clarity of mind and a healthy body, which is a GOOD THING. Many Sikhs I see have way too much desi ghee, and could do with a bit of Yoga (or some form of exercise). However, Kundalini Yoga goes beyond just exercise, but however you want to rationalize it in your mind, go for it. I’m not trying to convince you to do Yoga. That’s up to you. Just open your mind a bit and learn something about it so you don’t judge others out of ignorance. Wether you do yoga or play basketball, bottom line is that you should DO SOMETHING to take care of your "body temple". We often just think that if you just do Bani then all is well and leave out taking care of our bodies. We are the Sant Siphi (Warrior Saints) and if we are to be in a position to help and serve others we must be ready, physically, mentally, spiritually.
Ps. If you want to try doing some Kundalini Yoga, you can search for a certified kundalini yoga teacher in your area.
I agree with your comments, Today people are just lazy they want everything given to them on a plate. Especially some women who think if you exercise you will hurt yourself all they are interested in sitting and watching  soaps on the TV. Most of these women relay on medicines and take none/very little exercise they do not know wat they are doing to their bodies.Â
Some more additional resources : http://newsvote.bbc.co.uk/2/hi/health/7319043.stm
Yoga is a great form exercise for all and it not a Sikh way of life but it can be a good way of life for all.
including Sikhs.
I love the Sikh Missionary Society in Southall England.
They have dedicated an entire floor of the building as a Kundalini Yoga Center.
They are savy, smart, and dedicated to serving the community in depth. I met Angad Kaur
and many of the teachers there and look forward to teaching there again.
Blessings
Mata SatKirin Kaur Khalsa
Also, I was just reading one of Gurumustuk’s old post about yoga and sexual energy (sat kriya), I forgot the exact title of the post. But the intriguiing thing to me was when he says to search the word “Chakra” in SGGS. I knew there was some reference to yoga but did not even know there was so much reference to chakras. To me SGGS is like an OCEAN and the deeper one digs, the more beautiful things one finds. My problem or some would call it an excuse for being lazy is that I just can’t bring enough discipline to do regular yoga and meditation. But with 9hr-9.5hr work, 2-2.5 hr round trip commute, a little time with kids during their homework and sports practice, there is hardly time left for anything else but sleep.
Manjit Singh
You have to make time, you could practice yoga, or exercise and encourage your children too. You will feel the benefit in the long.
Just wanted to add the true reality, that Sikhs and yogic practitioners of the past sat in meditation for long hours and had great thoracic, and lumbar mobility with lean bodies and good flexibility. Today with sitting on couches and in cars, people are unable to sit in the meditative Lotus pose, so one has to question the reality of the situation in which we live. Thus, we should eliminate chairs, couches, and all such things and return to the Lotus posture that is inducive of correct meditation. Future research will show this to be true.
For those who find they don’t have time to practice Yoga… The irony is, when you make the time to devote part of your day to self-discipline, meditation and God, other parts of your life miraculously fall into efficient clarity and clear the path for you to continue the practice. It actually frees up more time… surprisingly? Not surprising at all if you’ve had the experience. Sikhs can jap, simran for hours and get the same experience… but if you were short on time, yoga and simran together takes you towards a holy experience of liberation faster.