Hi everyone,
Science does not mean only people in white coats working in laboratories....! 
Nobody said it did, so this is a straw-man.
Anything that has a specific method and system.... and the workings of which are understood and which are repeatable with predictable results....is a Science. It can be Yoga or meditation or dancing or singing or chanting or walking or even socializing.
I think you are using 'science' loosely, and no doubt there are many aspects of our daily lives that involve 'science': so we know there are biological reasons why some activities 'feel good' just as these days (thanks to graphite shafts and the use of titanium in the club-heads) science allows us to make more efficient golf clubs compared to old wooden variety, But care must be taken to avoid slipping in claims of 'science' that aren't suited to the methods of science, since to do so would be using the fallacy of equivocation by using the term ambiguously.
If feeling 'spiritual' involves certain conditions within our brain then that could be investigated, subject to an appropriate definition of terms and suitable methodology, but if the claim involves some kind of non-natural agency then you'd need a method suited to that: but this wouldn't be 'science' as science is currently understood.
In fact, religions often use music and singing, dancing, eating certain foods and so on to achieve certain mental states. They even advocate socializing, group meditations and chantings.
Indeed they do - these are ritualistic methods of reinforcing the message by encouraging group compliance via special procedures, words, songs, clothes etc etc. For example, I was went to an RC funeral once (my only experience of an RC service) and was astonished at the amount of ritualistic behaviour involved, people getting down on there knees and then up again at certain points or them suddenly all saying the same thing in a kind a call and response process with the priest. I suppose this works on an 'if I'm doing all this stuff there must be something behind it' basis.
As someone whose interest in sport is minimal I'm also very aware of the same thing going on when people on golf courses wear clothes they wouldn't be seen dead in elsewhere or, even worse, hearing someone on Radio 4 summarising a cricket game using a wheen of odd words and terms that only those in the know understand (why, in the case of cricket, they can be bothered in the first place is another mystery). That certain groups have their bespoke rituals isn't especially remarkable or significant: just 'par for the course'.
So..yes..many of the things that you people speak of can also be beneficial. There is a science behind them all.
The point is that the science behind many of our normal activities are not yet understood...rather the common man does not understand them. The science behind Yoga, Pranayama and meditations are however well understood to such an extent that very specific results can be achieved through very specific methods. Even temple visits, rituals, prayer, pilgrimages etc. have a science behind them.
Only where it involves aspects that are science-apt
And the science behind these techniques is a spiritual one in which the nature of the lower self is understood and the methods to discipline it is also understood.
Only if you define 'spiritual' in terms that are science-apt, else it ain't science no matter how much you'd like it to be the case.
Some of the methods may seem similar to workouts while others are meshed in with our normal day to day lives. But they all have a clear purpose behind them...though normal folk may not understand them as such....which really does not matter at all. Everyone need not understand the purpose behind drinking milk or eating apples..as long as they do it.
Nutrition, be it drinking milk or eating apples (or anything else) is an essential behaviour for survival, although sadly not for everyone, and is yet another area where humans have developed an approach that adds pleasure to the need: so we see a plethora of cuisines and resources to support them. I suppose you could call eating and drinking for survival 'purposeful', in a nutritional sense, but I suspect that you are using the term 'purpose' differently.
