5 LIES OF LACTIC ACID
The terms “lactate” and “lactic acid” are often used interchangeably, however, there is a difference. “Lactic acid,” is an acid. In a way to understand and compare it to exercising, “lactate” is produced in your body to keep your muscles fueled. If exercising at too high of an intensity for too long, the result is a buildup of lactic acid in your body. You may recognize lactic acid if you feel your muscles burn while working out. Lactate is good for your body yet there is only a certain degree of high intensity that your body can handle before it starts to buildup lactic acid. The less lactic acid you have built up, the longer and more efficient your body will be able to exercise. There are a lot of facts about both lactate and lactic acid and with facts, there comes opinions. Unfortunately, false facts have been distributed about both. For the sake of argument let’s call them “lies.” Today those lies will be put to rest as I explain the “5 Lies Of Lactic Acid.”
Lie #1: Muscles Produce Lactic Acid During Exercise
The muscles do not produce lactic acid during exercise. They produce a very similar compound called lactate. Whatever you call it, this substance is not produced as a waste product of anaerobic metabolism, as once believed. It’s actually an intermediate link between anaerobic and aerobic metabolism.
Lie #2: Lactic Acid Causes Muscle Fatigue
Most athletes believe that lactate (as we’ll call it from now on) causes muscle fatigue by making the muscles too acidic to contract effectively. This is not true. While the muscles do become more acidic during exercise, lactate is not the cause. In any case, far from hastening fatigue, lactate accumulation in the muscles actually delays fatigue by mitigating the effects of a phenomenon known as depolarization. During intense exercise, your muscles lose power in the same way a battery does: by becoming depolarized. The accumulation of lactate in muscle tissue during intense exercise partly counteracts the effect of depolarization.
Lie #3: Lactic Acid Causes Soreness
Lactate does not cause post-exercise muscle soreness. The simplest proof of this is the fact that very little lactate is produced during highly prolonged, low-intensity exercise, and yet it is this very type of exercise that leaves the muscles sorest in the following days. Post-exercise muscle soreness is actually caused by simple mechanical damage to muscle fibers, free radical damage, and inflammation.
Lie #4: Lactic Acid Does Not Contribute To Exercise Performance
Without lactate, you would not get fitter in response to training to the same degree you do with it. Lactate production during intense exercise stimulates a phenomenon called mitochondrial biogenesis after exercise. The mitochondria are little factories inside the muscle cells where aerobic metabolism occurs—that is, where oxygen is used to break down fats and glucose to yield energy. An increase in the concentration of mitochondria inside muscle cells is one of the major adaptations to training that improve endurance performance. And lactate makes it happen. This is one of the reasons high-intensity interval training is such a potent performance booster.
Lie #5: Muscles Do Not Use Lactic Acid For Fuel
Some athletes are aware that lactate produced during exercise can be “recycled” into glucose and used as fuel by the muscles, heart, and brain. But few are aware that lactate is also metabolized aerobically in the mitochondria as a direct fuel for muscle contractions. In fact, it has been estimated that roughly 75 percent of the lactate produced inside the muscle cells is used in this way, and only 25 percent leaks out into the bloodstream, where it can be measured through blood lactate testing.
Some of the world’s best endurance athletes, such as Michael Phelps, appear to produce significantly less lactate during intense exercise than lesser athletes. This makes sense if you believe that lactate is a toxic waste product that causes fatigue and does not help exercise performance in any way. But it doesn’t makes sense in the light of current knowledge about the effects of lactic acid. And it’s also very unlikely to be true.
In all likelihood, the reason there is less lactate in the blood of the likes of Michael Phelps during intense exercise is not that their muscles produce less, but rather that they use more. If, in the average endurance athlete, 75 percent of lactate is burned in the mitochondria and only 25 percent escapes into the bloodstream, in come very special athletes, perhaps 85 percent of lactate is burned and only 15 percent escapes.