Keeping bad company

On Saturday I went out for my planned 30 mile run with a couple of my experienced ultra running pals.  I have only ran more than 30 miles twice before so I knew it was going to be both physically and mentally tough.  Tougher still it was going to be mainly on tarmac.
As soon as we headed off I realised the pace was too quick for me to keep my heart rate in the low 150's.  But I can't expect my training partners to run for me when they both have races coming up so it was a question of hanging on in there.  With the exception of any hills this worked for the first 15 miles then it really started to get tough.
I fuelled as much as I could to make sure I wouldn't hit the wall but around 20 miles it was starting to become obvious I was struggling to keep up - the early pace was catching up with me.  So without any word of criticism or signs of frustration, when they got more than 250 metres in front they would turn round, run back and when they got level with me they turn and run with me.  This lasted for about 10 metres before they began to peal away again and there was nothing I could do.  I was hurting, every step was sore and  my hips were protesting.  I was doing the ironman shuffle and trying not to think about the biting wind and how cold it was if I began walking.
But mentally I knew that this was exactly what I needed.  I needed to dig deep, feel crap, feel sorry for myself and wishing that my running partners weren't so bloody good!  I felt I was holding them back which annoyed me but they are experienced enough to know that they were getting in a good training session and some extra distance constantly coming back for me!
I suppose if I keep such "bad company" then I need to be prepared for the outcome.  They will push my to higher limits and make me better.  A perfect training run with 4 weeks to go.  I took today off to allow my body to recover although I did get a green HRV reading this morning.  Rest is an important part of training and one that the youngsters aren't so good at!