Geraint Thomas on Sir Bradley Wiggins's troubled Giro d'Italia

Britain's Olympic track champion and Team Sky cyclist Geraint Thomas reflects on Sir Bradley Wiggins's troubled Giro d'Italia campaign in his latest column for BBC Sport.

I really felt for Sir Bradley Wiggins while I was watching him struggling before his withdrawal from the Giro d'Italia with a chest infection on Friday.

He was in great shape in terms of his fitness and was in a decent position in the general classification - but there is absolutely nothing that he or any other professional cyclist can do to stop themselves from getting sick.

You are either well enough to carry on, or you are not. Brad will have a vital role to play for Team Sky later on in the season too, and I'm sure that was taken into consideration before he pulled out.

It is a doctor that will have told him that his race was over, but he will have realised himself that his chances of winning the race had gone.

Riders pick up bugs and illnesses all the time - it might sound odd but I find I am particularly prone to them when I have been training really hard and am in really top shape, because I am so finely tuned and really lean.

Unfortunately that tends to coincide with the event that I have been preparing for. That was the case for me at the London Olympics when I was sick the week before my event, the team pursuit. I went from being at 100% and in the form of my life to 80%, but I had time to recover.

In a Grand Tour like the Giro d'Italia, you do not get that time.

It is even easier to pick up a bug on a big stage race because, if one of your team-mates gets ill with something contagious, it can quickly spread through the whole team bus.

Then, when you are under the weather, you are racing day after day after day and getting more and more run down. As you have probably seen at this year's Giro, the racing can be very demanding. It is just relentless.

A LONELY PLACE

In some ways I have been where Bradley was this week myself - feeling awful but just trying to keep going. There will be plenty of other riders in the peloton feeling the same way as he did.

But it is a heck of a lot easier to do it when the eyes of the entire cycling world are not on you, in the way they have been watching Brad in the last few days.

When I've been feeling rough in the Tour de France, I have gone in the 'Grupetto' [a group of riders who fall back off the pace and just look to finish the stage] and just battled through. I might have lost 30 minutes but nobody was bothered because I was not the guy who is one of the favourites to win. It has been very different for Brad.

I have not even mentioned the weather yet, which is something else Brad has had to contend with while he was ill.

Cycling through driving rain and in cold temperatures actually has more of an effect on you mentally then physically.

I don't mind racing in wet weather most of the time - I grew up in Wales so it is nothing new to me! - but it is a different story when you are feeling absolutely rotten and you know you are not going to get any better.

Everything adds up and your bike can be a lonely place. Brad will be disappointed with the way his race went but nothing went right for him and he did not get a chance to do himself justice.

PREPARATION PAYS OFF

Right now, I am in the middle of a block of training in Tenerife and we have been watching the end of each stage of the Giro after finishing for the day.

Fortunately for me, the weather is a lot better here than it is for the boys in Italy!

I have really been trying to focus on losing a bit of weight and that is coming down nicely.

I am climbing faster because of that, and it is a real boost to be able to see my hard work paying off in that way.

I don't find out for a few weeks whether I am in the squad for the Tour de France but things are going well and I feel like I am getting stronger all the time.

It is all about preparation, and I guess you could say the same about the best man's speech I made at an old friend from school's wedding before flying out to Spain at the start of May, although I hadn't written anything down.

If I had gone on the internet to find a couple of jokes to tell then I would have been worried about remembering them but I wasn't nervous because I knew what I wanted to say was in my head and that helped me relax.

My speech went pretty well, or at least I think it did, because I had the groom's dad crying with laughter. That helped a lot!

Geraint Thomas was talking to BBC Sport's Chris Bevan.