advice needed re disc/nerve problem

Can anyone advise please (and sorry if I ramble)?  I am in the middle of training for my first ever marathon and was rolling out my muscles on Tuesday evening after a four miler and decided to lie with the roller down my spine as indicated on the leaflet that came with it to stretch out my pelvis and chest. 

I took backache on Wednesday afternoon but it wasn't too bad.  On thursday morning it was still there and by the time I came into work it was excrutiating; in my lower back right round the front so that it was burning through my whole pelvis and radiating down the fronts of my two legs.

The doctor said it was probably a disc pressing on a nerve and advised me to hang up my running shoes that marathon running was for much younger people (I am 46).

I just want to know if this is likely to heal itself, if I should give up now or try and finish my training (for Belfast 6th May), obviously I didn't do my scheduled run on Thursday night nor will I run this weekend but will missing three sessions have a big impact on the overall training?

God I feel lousy! 

Thanks for any advice!

Personally I'd go and see a physio and get some proper advice - I'm having lower back problems and though I'll probably never do a marathon again I've never been told to hang up my running shoes despite having numerous injuries (I'm 47).  I know many people in their 50s and 60s who run marathons so I'd take what you're doctor says with a pinch of salt.

Hope you get it sorted soon

See a physio or a chiropracter / osteopath.  I'm not an expert on backs, but there is the possibility that it could be musclular rather than skeletal.  If this is the case then specific exercises and massage could do a lot to help you.

Tight or inflammed muscles can push on nerves too and cause similar symptoms.  Doctors don't tend to be that familiar with skeletal or musclular problems unless they have a specfic interest in those fields and can be too keen to prescribe rest.

Whatever the cause I would be reluctant to just let it heal itself.  Something caused the problem in the first place and it will continue to come back until you address the underlying cause.  You might be prepared to give up marathons this time, but what would you have to give up next time, and the time after...

Paying for proper treatment is well worth it for the improvement in the quality of life, in my opinion.

Back pain down front of both legs may well be referred mechanical pain from the back, rather than "trapped nerve".

Your doctor may have no knowledge of sports medicine, and to say that 47 is too old for marathon running is just absurd.

See a decent sports physio, and whilst you are waiting for the appointment, take it easy- everyone misses the odd session in marathon trainig- I think the plans are desigend with that in mind, so if the physio can get you going again,, you'll possibly be OK.