One of the most common problems encountered in any form of dirt bike riding is without a doubt arm pump. With many causes, some physical but most mental, let’s take a closer look at some of the causes and more importantly how to fix them.

Arm pump is simply when a rider’s forearms are filled to their maximum with a combination of blood and lactic acid, causing a major downfall in fine motor-skills which are needed to operate the all-important throttle, clutch and front brake controls. It’s quite similar to the feeling a 100 metre sprinter feels in their legs at the end of a run.

In effect, what happens is the muscle itself expands to its maximum size where the outer muscle sheath won’t allow it to expand anymore, followed by a feeling that your muscle is about the burst. Once the muscle has gone into this pumped-up state it can take quite a while to get it back to an efficient working unit. As you can imagine, this can be quite a dangerous situation when a rider is trying to jump a 30 metre triple and land centimetre perfect or negotiate their way up a rocky steep incline.

I can honestly say I have been one of the lucky ones over the years to have rarely suffered from arm pump, but on the odd occasion that I did get it I can understand what the fuss is all about. It almost feels as if someone else is riding the bike. The messages that your brain sends to your hands seem to almost be in slow motion, or even worse get scrambled along the way. Some riders choose to be smart and slow down, while others choose to ride through it which usually ends up in a big crash.

Various methods are used by the pros to relieve arm pump, as Jay Marmont demonstrates. Image: Simon Makker/Makkreative.com.

Let’s have a look at some of the classic causes of arm pump for dirt bike riders. Arm pump is always caused from holding on to the bike way too tight with your hands but it’s the actual cause of the rider holding on too tight that we want to take a look at.

Body Position
Far and above the most common cause of arm pump in riders that I have witnessed is poor body position. If a rider has a squatted standing position then their legs don’t do enough work to grip the bike, leaving the arms to do all the work. When in your standing position your legs should cover your air box and grip extremely tight inwards on the bike.

Solution: Gripping of the bike should be approximately 70 percent legs and 30 percent hands. When you successfully accomplish this you will minimise arm pump, blisters on your hands, tearing up your grips and tearing up your gloves.

Feeling Uncomfortable
For a lot of riders out there that don’t get the opportunity to practice during the week, race day can bring arm pump, particularly in practice while the rider finds their rhythm once again.

Solution: Take your time to warm up and stretch before practice. Don’t go flat out in your first couple of laps but ease your way into it.

Extra Speed
A lot of semi-pro riders who are knocking on the door to get their first factory ride tend to practice at a different pace to race day. They ride all week long at different practice tracks and suffer no arm pump until race day. The cause here is normally a combination of two things – anxiety on race day, along with the extra speed needed on race day to perform at your best.

Solution: Boost your intensity of practice sessions during the week. Try getting your mechanic to record some of your sprint lap times and set these as your lap time goals for weekly practice sessions. If your mechanic or dad can swing off the pit board for you during the week this will help you keep up your intensity. Also try to ride with other fast riders to get that adrenaline flowing.

Jumps are a perfect section of any race track to relax your arms mid-flight. Image: Simon Makker/Makkreative.com.

Supercross
If there is one part of our sport that seems to bring on the arm pump it is Supercross. Mainly due to rider comfort, a rider will tend to hold on for dear life a lot more on a Supercross circuit than an outdoor Motocross track.

Solution: Practice makes perfect. The more you practice Supercross, the more comfortable you will be and the looser your hands will grip the bars.

Fitness
In this example, the rider will normally have a terrific style, gripping mainly with their legs while using minimal hand strength. However, if the rider is lacking in leg strength and fitness they will eventually tire in the legs and the standing position will sacrifice, causing the rider to have to grip a lot tighter with their hands, the end result being arm pump.

Solution: Increase overall fitness and leg strength so you can keep your good form through the entire race.

Suspension
This example is one of the only cases where the rider isn’t really at fault. The rider may have perfect technique, be extremely fit and ride regularly but still suffer from arm pump due to poorly set-up suspension. Typically you will find that forks set up too stiff will be the main cause of arm pump in the suspension department due to constant chattering of the arms, but suspension set up too soft will also cause arm pump, causing the rider to panic when preparing for a hard landing.

Solution: Take the time to learn about suspension setup and constantly monitor your own settings. Don’t be scared to get the screwdriver out and have a play with the clickers during the week.

Diet
A poor diet full of sugar and lacking in nutrients will also help trigger arm pump. Simple sugars are proven to speed up the lactic acid process which is a key factor in arm pump. It sounds too easy but drinking plenty of water not only minimises arm pump in the first place, but also helps flush the lactic acid out of the system once it is in there.

Solution: If you can’t bring yourself to have a healthy diet all week long, then at least watch what you eat a couple of days before an event. Keep off sugary, sweet food and fried goods while trying to eat a fair bit of unbleached grains. Two litres of water per day is a bare minimum.

Hopefully that has shed a bit of light on a few areas to do with arm pump. Unfortunately there are so many areas to cover but having an understanding of each of them will go a long way.