I'm totally unfit but have decided I'm going to do an extreme mud run.

[VivaLeBeaver]

5k of obstacles, mud, tunnels, mud, cargo nets, mud, etc.

Obviously I'm going to need to do some training. Yesterday I did an 8k bike ride. Today I ran 1 min/walked 1 min for a total of 20 mins. Neither killed me too much.

So how long before I can do a 5k mud run?

They have 10k ones as well but don't want to over stretch myself.

Has anyone done one before? Are they really tough?

Thanks, will check out apps.

I've done a 10k run before, years ago. Just unsure how much worse a 5k extreme run is compared to a normal run.

When's your beach run? Have you seen a difference in fitness already?

I did it!!! It was bloody fantastic.
I started the c25k in December (when ds was 6 weeks old) and ran the minor(5k version) of the BMF Major Series in March. I mostly did it because I needed to enter something to ensure I kept going with the running and I thought the obstacles would break it up a bit.
I found there were queues for the first few obstacles which made the running much, much easier.

It was so much fun that my husband is currently doing c25k so he can do the minor in October. I'm dead jealous so I'm giving serious thought to the wolf run instead which is 10k.

I used the run double c25k app on my phone and did sod all training for the obstacle bits of it apart from paying with my 2.5 dd at the swings.
One thing I would recommend are waterproof socks though.

All sounds good.

Do you wear normal trainers with your waterproof socks?

I used normal trainers - well cheap trail shoes from sports direct - and normal socks. neither the shoes nor the socks ever really recovered... Somebody I met on the way around said she was wearing waterproof socks and apparently they were awesome!