The onset of muscle fatigue has hampered many athletes from achieving their maximum potential. The lactic acid buildup is a byproduct of anaerobic metabolism. Under normal activity levels, the body mostly relies on aerobic metabolism and hence lactate (another name for lactic acid) buildup is not a major concern.
However, with increased activity levels, specifically, when the metabolism switches from aerobic (oxidative) to anaerobic (glycolytic), as in power activities performed at high heart rates, lactate levels quickly build-up, which, if not cleared from muscles, cause fatigue and a burning sensation.
But how quickly lactic acid is cleared and how quickly a person feels this fatigue is also influenced by your genetics, especially the MCT1 gene. This article provides insights into how individual differences affect the lactic acid clearance rate and muscle fatigue.
How Do Muscles Become Fatigued?
During short-term power (anaerobic) exercise, our body uses substances such as ATP and creatine phosphate (CP) within the first 7 seconds to produce energy. This signals the body to start glycolysis, a process to utilize the glycogen (stored glucose) to produce energy. When glycogen is broken down to release energy, which allows the muscle movement to continue. During this process, a substance called lactic acid is formed. Small amounts of lactic acid operate as a temporary energy source, thus helping you avoid fatigue during a workout. However, a buildup of lactic acid during a workout can create burning sensations in the muscle & limits muscle contraction, resulting in muscle fatigue. For this reason, it may be desirable to reduce lactic acid build-up in the muscles. However, if you are a bodybuilder, the lactic acid buildup has been shown to be highly anabolic- meaning, good for muscle building. Bodybuilders routinely work out to feel the “burn” in their muscles.
Genetics and Muscle Fatigue
Monocarboxylate transporters (MCT) regulate the transport of lactate and many other substances and remove lactic acid from the muscles. The MCT1 gene influences the amount of MCT you produce. The more you produce, the quicker the clearance rate, thus the delay in the onset of muscle fatigue. Individuals with a certain type of the MCT1 gene produce higher levels of MCT, making them more suitable for endurance-based exercises than individuals with the other types of the MCT1 gene.
Diet Tips To Reduce Muscle Fatigue and Lactic Acid Accumulation
| Adequate magnesium levels in your diet will help the body deliver energy to the muscles while exercising, thus limiting the buildup of lactic acid. Foods rich in magnesium include legumes like navy beans, pinto beans, kidney beans, and lima beans, seeds such as pumpkin, sesame, and sunflower seeds, and vegetables like spinach, greens, turnips. Omega-3 fatty acids help the body to break down glucose and limit the body’s need for lactic acid. Food sources of these fatty acids include fish like salmon, tuna, and mackerel, nuts and seeds like walnuts and flaxseed, and plant-based oils such olive oil, canola oil, and rice bran oil. B vitamins: help transport glucose throughout the body and help provide energy to the muscles. Food sources of B vitamins include leafy green vegetables, cereals, peas and beans, fish, beef, poultry, eggs, and dairy products. |
BOTTOM LINE: If you are an endurance runner, excess lactic acid buildup is undesirable as it leads to fatigue. If you are a bodybuilder, lactic acid, being highly anabolic, is good for muscle growth.
Discover your genes and align your training with your genetic type. Try Xcode’s fitness genetics test which can tell you whether you carry faster, slower or both versions of the MCT1 genes . Write to us at hello@xcode.life
About Xcode Life's Gene Fitness Report
Updated May 12, 2023
