I’m going to get a little technical today giving you the low down on lactic acid. There are misconceptions about lactic acid that need to be cleared up. Among other things, I will reveal how understanding lactic acid and your lactic acid threshold can have a significant impact on your endurance. And for those of you participating in cross-fit type activities, this is one of the things that is happening to your body as you transform.
As I alluded to above, the advantages and disadvantages of lactic acid are some of the greatest misconceptions in the health and fitness industry. For many years, trainers and coaches have taught their clients and athletes to avoid lactic acid (lactic threshold) at all costs. However, over the last few years, scientists have shed some new light on lactic acid and it appears that this chemical process is a friend to us, not an enemy.
What Causes Lactic Acid
Through years of research, scientists have discovered that lactic acid is fuel for energy within our bodies and not just a waste byproduct leftover from a strenuous workout. When you perform strenuous anaerobic workouts, the body burns through your stored muscle glycogen for energy in a process known as glycolysis. Through several more complicated processes, the glucose is converted into pyruvate (anaerobic glycolysis), which in turn releases adenosine triphosphate (ATP).
However, if the body does not have enough oxygen to meet the needs of the muscles which are under a strenuous anaerobic workout, then the pyruvate cannot enter the mitochondria to undergo an oxidative process. The pyruvate then transforms into lactic acid, also known as lactate.
The Function of Lactic Acid
As previously mentioned, lactic acid is now considered a positive process within the body during exercise and not the wasted byproduct that many experts used to claim it was. Lactic acid allows glycogen to continue to be broken down and used for energy. Additionally, the lactic acid can be transported back to the liver where it can be converted back into glucose. This is part of the process known as the Cori Cycle.
Lactic Acid Buildup
Despite the benefit of energy that scientists have discovered in regards to lactic acid, too much of this substance can cause potential problems. In addition to lactic acid, the body produces hydrogen ions during the anaerobic glycolysis process. The accumulation of hydrogen ions and lactic acid in the bloodstream can cause the blood and the muscles to become acidic. This can lead to other metabolic processes being shut down due to high levels of acid.
In regards to the muscles, individuals may experience a burning sensation, which is a sign that the body is being overworked, due to the high level of hydrogen ions and NOT the lactic acid as was believed for many decades. Once you slow down your intensity level, in addition to some rest, the acidic levels will begin to subside and the burning will cease along with the previously halted metabolic processes returning back to normal.
Delayed Onset Muscle Soreness
Delayed onset muscle soreness (DOMS) is the muscular soreness that’s often experienced roughly 24 to 72 hours after a vigorous bout of anaerobic exercise. Symptoms of this soreness range from muscular tenderness and swelling to a limited range of motion. Up until the last few years, many experts believed that lactic acid buildup was a direct cause of DOMS. However, recent studies have debunked this theory. In fact, my research shows that the exact cause of DOMS still remains a mystery. What we do know, and is obvious to most, is that the muscular damage from exercising leads to soreness.
The lactate threshold is typically defined as the point where intense exercise causes the buildup of lactic acid in the bloodstream. This is also the direct point where the body can’t further remove or convert the lactic acid back into energy. The goal for athletes is to push this threshold as far as possible to allow them to continue to perform their activity as long as possible.
However, some individuals may experience a low lactic acid threshold. There are several reasons that can contribute to this problem:
- Not enough oxygen to the cells.
- Your heart and lungs aren’t working as efficiently in transporting oxygen throughout the body.
- Low levels of mitochondria within the muscles.
- Your body lacks enough enzymes to perform the necessary processes to breakdown glycogen or pyruvate.
Lactate Threshold Training
The lactate threshold is usually reached between 50% and 80% of one’s VO2 max, which is the maximum amount of oxygen uptake that an individual can use during vigorous or maximal exercise.
Unfortunately, most individuals don’t have the proper technology or access to a lab to determine your VO2 max. A popular method for gauging one’s lactic threshold, if you don’t have access to a lab, is to train at 85% – 90% of your maximum heart rate. This is a common method that many coaches and trainers use in lactic training. There are several formulas for determining your maximum heart rate including 220-age. Once you get your maximum heart rate, you can then determine your lactic threshold based on 85% to 90% of your maximum heart rate.
Training to improve your lactic threshold typically involves bouts of intense periods of exercise, with the goal of pushing the duration longer each time. Just like I’ve detailed before, your training must be progressive, and in this case, your ‘progression’ is increased duration each time (even if it’s only a little bit).
These periods of intense exercises are performed at 95% to 105% of your lactic threshold which forces the body to better absorb and remove higher levels of lactic acid. Ultimately, by pushing the duration of these periods of intense training, your body will be able to push the lactic threshold back further and allow you to train longer at high levels of intensity and energy.
Ok, if you made it this far you can consider yourself more knowledgeable on lactic acid than 99% of the people out there today (including most trainers). So what does it really mean for you at the end of the day in your quest to put on more lean mass?
Lactic Acid and Muscle Development
Through advanced studies by numerous scientists and doctors, it’s believed that lactic acid is moved into the mitochondria through a special protein that transports the lactic acid and helps the mitochondria to use it as energy within the muscles.
Through intense, prolonged, and progressive anaerobic training, you can increase the size of your muscle mitochondria, which will allow for more lactic acid to be absorbed thus allowing athletes or individuals to train longer and harder.
Additionally, lactic acid also helps in the process of muscle contractions as it allows for potassium to get into the muscles by removing chloride. Endurance training is highly recommended by lactic acid experts since it trains the muscles to push the lactic threshold, increase the mitochondria mass, and allow the muscles to work longer and harder.
Yeah, I know – it’s kinda tough reading and technical, but I did warn you at the beginning! The big picture here is that lactic acid isn’t the negative we’ve always thought it was, and the burn we feel when pushed to the edge is likely caused more from the H+ buildup than the lactic acid buildup.
In fact, there appears to be some validity to the idea that lactic acid is actually more of a fuel source, and to that end, I’m investigating the possibility of a supplement that can harness that power for more endurance in the gym…but we’ll see where the research leads!