Confused about chaffing

A friend of mine and i were talking about marathons. I am training for a marathon in May and he has run a marathon a few years ago.

he mentioned chaffing, and advised to use vaseline on areas like legs, thighs, arms, etc...........

I did not know this, as i've never heard of it before.

Is it really necessary? do runners suffer from chaffing?

I thought that it only happened when skin is exposed on runners who run in shorts or vests, but the thing is that I never run with shorts and vests.

I always, always run in long running trousers and long sleeves, regardless or weather (for personal modesty reasons),

until now the longest i have been running is two hours 15 minutes, and i was ok,

and this is why i was wondering if someone here can advice about this: can you suffer from chaffing if you wear clothes? does chaffing happens with long trousers and long sleeves?

Chafing can occur whenever the skin rubs against fabric- it doesn't matter what sort of clothes you wear.  The number of layers you wear and the temperature can also affect how bad the chafing is.

I know I always need to something (usually Bodyglide) on my nipples and around my gentlemanly bits.  I also have certain bits of kit where I know I'll need to put extra lubrication on.

CHAFING, people, CHAFING.

It can happen with any clothes and not only when you are running - but if you don't suffer from it, you don't need to worry about it. You won't get chafing on exposed skin - although you might get frostbite or sunburn 

You should do some of your longest training runs and warm-up races in the same kit you're going to wear on marathon day, that way if you're going to get chafing you'll know about it before race day and can deal with it. You should not wear any untried clothing on race day as that's just asking for problems.

Being a man of a certain age I always tape up my nips and put a little bodyglide in the groin area for longer runs, but otherwise it's never been an issue of me. Having done the 23 mile drink station on the London Marathon several times however it's amazing how many men you see coming through with two blood stains running down their shirts or with blood running down the inside of their thighs. And it's even worse when it's a wet race.

i discovered to my dismay that my club vest causes cafing. Most painful. I tend to wear a T underneath it to avoid this.

If you always\wear the same kit and it has never been an issue then it is unlikely to rear it's ugly head come marathon day.