Training & Nutrition - Training advice

I had a very strange experience MTB-ing on Saturday, a few hours into my ride I lost it physically. Suddenly, I found it very difficult going and I couldn't keep up. My legs wouldn't turn fast enough. On top of that I had cramping in my calves and I could barely flex my hands and fingers. While I'm not half as fit as I want to be, I know I should have had more in me. There were people I'm normally in better shape than who I just couldn't keep up with. It turned into a very disappointing day.

Somebody suggested my problem was I'd only eaten a bowl of cereal before I came out and I simply ran out of fuel in my body and lost it. Is that possible?

Related to this I really want to get stronger, and was wondering if going for a running one or two nights a week when Im not cycling would be a good idea to increase all over fitness/cardio?

Thanks!

I think most people on here advocate some form of replenishment of fuel every hour.
Furthermore, IMO you need to have an electolyte drink as well. Don't know if you have it over there but SIS Rego GO or PSP 22 are very good. I used to do a bit of running but have found the changeover to cycling harder than I thought. I.e. I'm rubbish at it. Mind you, I was rubbish at running too :(

It does sound like you hit a deficit in calories or hydration. If more than an hour of riding then you need to eat and drink correctly prior to the start. If you wait until you feel thirsty or hungry your body can not re-energize itself with its consumption. It does take more than just water too. Your body uses and sweats out more than just h2o so give it what it needs to keep its chemistry balanced.

You bonked.

Welcome to cycling!

Somebody suggested my problem was I'd only eaten a bowl of cereal before I came out and I simply ran out of fuel in my body and lost it. Is that possible?Yeah, I think that's a good guess. If you don't know how hard an how long you can go, it's easy to just get excited and just run yourself out of gas.

Not much different than little kids that go and go until they tucker-out and get cranky.......

You bonked.

Welcome to cycling!

Word!

Since I race CX I run 10-12 miles a week with no ill effect on my cycling. My races are only one hour, but we're at 180BPM plus most of the time. I also SLOWLY built my running base over the years.

the cramping sounds like dehydration, and you definetly didn't eat enough. If it was much warmer than usual that could have been a factor as well.

5 pints of guiness the night before would also affect your performance.