Muscle Fatigue from Cycling
People have been using bicycles as a means for transportation, exercise or recreation for years. Whether you like to ride your bike down to the coffee shop or ride with your local cycling club for long stretches at a time, you’ve probably experienced some degree of muscle fatigue from cycling. Even the most experienced cyclists deal with it. In fact, it’s an anticipated part of any given race. Learning what it is and how to deal with it is an important step to take towards understanding and improving your cycling performance.
What is Muscle Fatigue?
Muscle fatigue from cycling refers to a decrease in muscle strength during performance, often accompanied by soreness or physical exhaustion. Muscle fatigue can develop over time during any consistent activity, such as cycling. It can target specific muscles or the whole body. There are a few common causes that lead to muscle fatigue while cycling which we will discuss below. These forms of muscle fatigue happen to even the most experienced cyclists, but can be managed during a ride.
In many cases, experiencing muscle fatigue post-ride is a good thing. It indicates that your muscles have been working hard, and that they’re now repairing and becoming stronger for your next ride. But, there are instances where determined cyclists try to push past muscle fatigue without giving their bodies adequate rest. In these instances of overtraining, cyclists are in danger of potentially debilitating injury.
Lactic Acid Buildup
One of the more common causes of feeling fatigue in the muscles is the production of lactic acid, a waste product in the body. To understand what causes the body to produce lactic acid, you need a basic understanding of what causes the muscles to work. Our muscles cause our bodies to move by contracting and relaxing. In order to contract, of course, they need energy. The human body takes carbohydrates and fats and breaks them down into the energy needed to move the muscles and the body. But to do this, our body and our cells need plenty of oxygen. The use of oxygen to produce cellular energy is called aerobic respiration.
But, if we are not capable of providing enough oxygen, then our bodies turn to anaerobic respiration instead, which uses stored energy. This stored energy is called glycogen, which breaks down into glucose, then pyruvate and, finally, lactic acid. An accumulation of lactic acid in the muscle tissue will reduce the pH levels. Since the proteins in muscle cells can only function within a certain range of acidity, the reduced pH levels inhibits muscle contractions. This is one cause of the burning or stinging sensation that can come with muscle fatigue from cycling.
If you’re experiencing the stinging resistance that comes with a buildup of lactic acid, resist the urge to stop moving. Excessive lactic acid is most efficiently remedied by gentle exercise. Instead of stopping, slow down your pedalling and increase your breathing. Oxygen can help turn some of the lactic acid back into glycogen.
Anyone who has participated in long, endurance-based rides is familiar with the bonk. It’s a funny name, but a serious bummer. You’re riding along and feeling great. All of a sudden your muscles turn to jelly and every ounce of your energy seems to dissipate. The bonk refers to that out-of-nowhere loss of energy that tends to occur one or two hours into a ride.
Pedal pushers will be happy to know that the bonk is not just a random misfortune, but an easily-explained event in the human body. This type of muscle fatigue from cycling sets in because of the depletion of the stored carbohydrates—aka glycogen—in the muscles. Essentially, when you bonk your body is running out of energy resources. You can save yourself from the bonk by eating a sufficient amount of carbs on the days before you ride. Oral carbohydrate supplements are also a popular saving grace mid-ride. Their portability lets you take them while you’re in the saddle. However, try to take a carb supplement before the bonk, or else you’ll still have to play catch up on your low glycogen.
Recovering from Extreme Fatigue and Avoiding Overtraining
So far we’ve looked at two naturally-occurring forms of muscle fatigue from cycling that can impede your performance mid-ride. Once you’ve pushed through any exhaustion during a race, it’s natural to also feel fatigue post-ride. If your fatigue or muscle soreness lingers until the next time you head out on your bike, that’s not necessarily a bad thing. On the contrary, it’s generally a sign that you’re pushing yourself to perform at your very best. As a result, the muscles you use when cycling are strengthening and your performance will grow even stronger.
That being said, it’s important to recognize the difference between pushing yourself to your limit and pushing yourself too far. Overtraining can lead to a dangerous level of muscle fatigue from cycling. If you’re consistently overtraining you might notice headaches, a change in your appetite, difficulty sleeping, or exhaustion throughout the day. When you go to ride, your chances of injury will be much higher. This is because not only does overtraining contribute to muscle fatigue from cycling, but it can also be accompanied by exhaustion in the nervous system and your neural responses. In other words, your technique and posture will become poor and sloppy when your body is exhausted, created more opportunities for injury.
The biggest thing you can do to avoid overtraining is scheduling your rest days. Don’t let yourself ignore your body’s need for a day away from the saddle. And even though you'll be off the bike, make sure to foam roll your muscles and mix in some light exercise like walking or water aerobics. The best way to tell is by listening to your body and only doing what feels good.
A good stretching routine is another thing that will keep you from overtraining or possible injury related to fatigue. Stretching once just after you ride is not enough. Find something that lets you use resistance stretching to build strength in the muscles around your joints. This will give you more power and stability during every ride and decrease your chance of fatigue and injury.