I recently sat down with both Visiontrack Ducati rider Christian Iddon and Honda Racing UK’s Glenn Irwin to discuss many things including arm pump, which has been a hot topic of discussion lately.

Fabio Quartararo became the latest high profile rider to suffer from arm pump as he lost MotoGP victory in Jerez due to it. 

The French rider was initially slowed by a few tenths before a complete drop off of around three seconds compared to the type of lap times he was delivering whilst in the lead. 

And during my recent interviews with both BSB riders, this was brought up as a point of discussion to find out from their perspective what might have happened, but also their own experience of having the issue.

Crash.net: I wanted to get your view on arm pump. It’s something that’s been in the news quite a lot recently as I’m sure you’re aware of Fabio Quartararo in MotoGP losing a race win due to it at Jerez, while Aleix Espargaro is scheduled for the surgery following Le Mans. Is it something you’ve had before, what are your thoughts on it and the effect it can have on a rider? 

Christian Iddon: "Well as someone who’s suffered with it terribly - I’ve had both arms done as you can see by the scars. I never suffered with it at Supermoto but I suffered with it terribly when I was Motorcrossing. I think there’s different levels of arm pump. Some people say they get arm pump and only lose two tenths of a second a lap. I think some people get arm pump and are two seconds off the pace, which is the sort of arm pump that Quartararo got, and it is the sort of arm pump that I usually get. 

"It got to the point where it was very dangerous. I've had times where I physically couldn't close the throttle or brake, it’s that debilitating. You can imagine when you’re riding a race bike at pace and that happens, it’s scary, scary stuff. My arm pump story is long, but I’ll shorten it down. Arm pump generally comes from your muscles being grouped and the way that they’re grouped is like having a blanket around them - like a sleeping bag. So essentially, if the sleeping bag is too tight when the muscles are contracting and when you’re working the bars, the levers, the muscles inside the sleeping bag get bigger and if the sleeping bag is too tight they can’t go anywhere - essentially starve of oxygen - therefore resulting in arm pump. 

"That’s the long and short of it. I tried for years to manage the situation. Obviously the more tense you ride the more your muscles are contracted, therefore if you’re riding tense you tend to get it. You have races where you don’t because you’re riding well, you’re fluid with the bike, so it’s frustrating in a way. Sometimes it’s more frustrating when you don’t get it all the time, probably like Quartararo’s situation. I don’t know why he tensed up because he had a beautiful lead, was riding on a crest of a wave, and that’s one of those situations where he had it and it’s almost unexplainable. That’s not the situation you would typically get it in. I would expect him to get arm pump when he was off the pace and riding beyond his means a little bit. 

"That in Jerez was contrary to what you usually see. The only way I could really manage it was by losing a lot of weight. I build upper body muscle really easily which sounds great because then you have strong arms, but actually that’s completely the contrary as the muscles become too big for the bags that they’re inside of. 

"So the only way I could really manage it was to lose so much weight that you become catabolic. Catabolic is where your body breaks down muscle as an energy source which makes the muscle smaller. I was probably in that state for about a three to four year period but I had to have a body fat percentage that was so low that it was detrimental to health and not a good place to be. Once I got the arm pump surgery it was so much easier in life really. It was a big relief in every way." 

Crash.net: Arm pump has been doing the rounds a lot lately with a few MotoGP riders suffering from it - none more than Fabio Quartararo who lost the race win in Jerez due to it. Is it something that’s been an issue for you and what are your views on how it happens. 

Glenn Irwin: "It’s a good question. I’m not a medical expert although we think we are because we’ve had nearly every injury under the sun. I’ve had a really bad arm pump before with one case at Oulton Park on the PBM Ducati. I was a few seconds ahead of Shaky [Shane Burns], and he finished something like seven seconds ahead of me because my arm was totally gone. But that was totally preventable because of misplacement of the lever. 

"It’s strange because when you’re relaxed you don’t tend to get it. There’s some tracks where you definitely don’t get it, ones that have long straights and give you breaks you won’t get it and ones where you’re not fighting with wheelie. But with Quartararo, he was so relaxed at the weekend, doing such a good job and probably knew he had the race before the lights went out without a variable happening which obviously did happen. But he got it really, really bad so it’s difficult to know what happened with him. Was it a case of having random arm pump or it could be that something with his lever went on. 

"Jeremy McWilliams told me a great thing once. He said if you ride and you’re not getting arm pump, measure the angle of your brake lever and where you have it set and also the lever span and take that with you for the rest of your career. That is my firm belief. Yes my arms pump up of course because you can’t come in off the bike and say ‘look at my forearms they’re like a bag of jelly’, if you play tennis your arm pumps up and I do play tennis. 

"I suffer with my left shoulder a bit more because of injuries at Knockhill in 2017 - I’m actually going to the doctors on Monday about it just to have an injection. We all have niggles. Arm pump isn’t one of those high up on my list but I certainly get arm fatigue, but not to the point of losing three seconds a lap."