During long rides, many cyclists begin to experience numbness and weakness in their hands. These symptoms can become more pronounced over time and appear earlier on a given ride, requiring frequent rest and position changes.
What is the reason for the numbness?
Numbness is caused by excessive stress or pressure on the nerves. Cycling affects the median and ulnar nerves (if you've heard of carpal tunnel syndrome, you must have heard of median nerve problems).
The median nerve and several tendons run through a "tunnel" under the wrist. Keeping your hands bent up and pressed against the handlebars for extended periods of time can put too much pressure on the area, causing numbness, tingling, and weakness in half of the thumb, index, middle, and ring fingers.
The ulnar nerve passes through the wrist and the little finger side of the hand. Holding the handlebars puts direct pressure on the area, causing numbness and tingling in the pinky and ring fingers.
Symptoms may go away shortly after nerve pressure is relieved, or they may persist and worsen, possibly leading to muscle weakness in the hand.
Self-service solutions
There are a number of things you can do to relieve persistent numbness in your hands.
Find a bike accessory: Are you riding on the right size frame? Are your bike components fine-tuned for optimal body mechanics? Professional bicycle accessories can help answer these questions. Suggested modifications might include: moving the seat back, changing the seat angle, lowering the seat, and raising the bar -- all of which redistribute your weight to your back and away from your hands. It may also help to adjust pad/shift lever cleat position, stem length and hood position.
Wear compression gloves: The vibration itself puts pressure on the nerves, but it can also make you grip harder than usual. Wearing padded gloves, especially around the hypothenar eminence (pink side of the hand) can help - just make sure they're not too tight, as this can make the situation worse.
Grip: If you have a mountain bike, consider using thicker, softer handlebars that are also sticky so you don't have to grip as hard. For road bikes, you can use handlebar gel and thicker tape on the handlebars. Ergonomic handles are another option. Their special shape positions your hand correctly and helps release pressure points. On the more expensive side, carbon rods dampen vibrations and reduce nerve stress.
Do your bike tuning: Remember that reducing vibration is key, so make sure your suspension is tuned properly and your tires are at just the right pressure (not too much air).
Use your core: At a steady pace, are you able to lift your hands off the handlebars without falling forward? If not, your hands may be carrying too much weight because you are relying on your arms to stay upright instead of using your back and core strength. As you ride, pay attention to your overall position and the level of engagement of your back and core muscles. Turning your attention to the mechanics of your body will provide the opportunity to make real-time adjustments to reduce stress on your arms and hands.
Adjust your hands: Change the position of your hands throughout the ride to avoid putting the same constant pressure on your wrists throughout the ride. On a road bike, alternately hold the drop bar, the hood, and the flat part of the bar.
Relax your elbows: In all poses, keep your elbows relaxed to fully absorb vibrations from the road or trail. Relaxing your elbows will also work your core and back muscles and take extra pressure off your hands.