hello, here's what i can offer, i hope i'd be of help to you :D
Can't remember much, but here goes:

warm up:
1. as it suggests, to warm up your muscles. The purpose is to get your circulatory system flowing more through vasodilation. This way your muscles would be better supplied with oxygen and nutrients for your primary activity. Muscles are hence 'primed to fire' and are ready for your primary activity!

Stretching after warmup:
1. Stretching is also warming, and improves blood circulation.
2. Increases your range of motion, reducing possible injuries such as tears resulting from overstretching.
3. improve biomechanical efficiency.
4. reduce likelyhood of cramps

Post work-out stretch:
1. stretch your muscles so you gain flexibility and not have your muscles grow as in inflexible clump
2. Restore lenght of muscles to aid in recovery
3. Improve circulation and hence allow for nutrients to be shuttled into your muscles, and allow for lactic acid to be cleared more efficiently (i think). Can couple with massage to flush out lactic acid.
4. by removing lactic acid you are less likely to get the post exercise muscle aches.

Hope i've been of help! :D sorry kinda rushed

I like to warm up before exercising. I will try to do the activity that I have planned at a lower intensity to get the blood flowing from my organs into my muscles. I'm not big on stretching before training. I was told it can lead to injuries. No personal experience with it but just something I avoid.

I will cool down after training. Again, whatever the activity is but at a much lower intensity.

Thanks awx & MJS for replying.

Erm...it wasnt what I was looking for oops ....

ds

oh no.. i just realized that too. sorry!

You have a point. The reasons why these steps are included is to maximise performance. With those who engage in physical labour as a job, they wont necessarily be looking at optimal performance.

Saying that, these guys would have to of started off somewhere so when they start lifting etc, I bet they had the same post training symptoms athletes have. The difference is that the loading with these guys is probably fairly constant where athletes will be looking to increase loadings etc regularly so post training symptoms are likely to be present more often. With those who participate in physical labour daily, there is little progression or overload once they have adapted to the stimulus which is fairly constant. The more they do the same task, the more efficient they become meaning less stress and stress responses. When the stress overloads them, then they will probably have post training responses.

I would not apply this theory to athletes as stated they have an ever changing loading and optimal performance is important to make progress.

Isn't there alot of research which shown's that stretching doesn't prevent injury ?

Yes there is research that shows no/little reduction in injury.

If you look at muscle function after stretching, then you are changing the length-tension relationship. Also you are changing muscle stiffness which maybe necessary for joint integrity. If this is compromised then potentially the risk of injury is greater. When a muscle has a new length, the compliance of the muscle changes staight after the stretch. This means that the time to take up tension increases which may only be a very short period of time (hence why research has shown decrease in muscle RFD for the same reason) but could again compromise mechanisms protecting athletes from injury (golgi tendons and muscle spindle fibres) - this last point has not yet been substantiated so is mechanical theory.

A few points made in earlier posts about pre training stretching. Increased RoM of a muscle may not be necessary where as mobility of a joint is. Stretching as stated above wont decrease injury risk or improve mechanical efficiency and would say physical status would determine cramps or not.

For post work out stretching, more literature is looking at flexibility while the muscle is in a rested state so pre exercise and 'cold.' Not sure about circulation but length of muscle will probably be greater than pre exercise so only looking to improve length (referto previous point).

I rarely static stretch before training unless I know I am having an issue with flexibility. I will always warm up much the same as MJS after a non specific warm up of mobility and drills. I will intruct the athletes I work with to do the same.

I have experience with farm labourers & other similar hands on workers, the majority of whom suffer in later life for their toils due to the wear & tear & the nature of their physical jobs. shock
Maybe if they had followed a structured warm up approach before starting work they would not suffer as badly in later years but this really needs to be done in the very young as this is when they learn & I cannot see farmers & labourers starting work each day with this discipline. shock

Regards,

Max. wink