Traditionally, the main focus on gauging the quality of a workout is the feeling of burn in your muscles. Want to grow muscle? Better get your pump and feel the burn. Want to get stronger? Burn it, baby. Want to shed fat? Then you better feel the burn!
So does the feeling of accumulation in your muscles as you exercise actually improve your ability to accelerate and move faster as an athlete? The answer is no. I'm going to list the pros and cons of why you want to rely on this energy source.
- Serves a constant role in energy metabolism
- Lactic Tolerance Training (LTT) prevents
- Growth Hormone Release
- Conditioning effects occur very fast
- Second Wind Theory
- Research say it makes you slower
- Negative physical effects
- Performance downfalls
- Moderate effort or speed isn't real speed
Regardless of what level of intensity you are training at, there will always be energy production from the lactic acid pathway. It's quick, easy, and very convenient for working cells. Since the system is always working from one degree or another, being able to buffer and reduce the negative effects lactic acid may create is necessary. Research in this area seems controversial based on what I have read, but the theory is very logical. As you will see later on, lactic acid has the capacity to shut down working muscles or lower the productivity to contract forcefully, so it may help to train specifically for lactic buildup so the body can learn how to adapt and keep levels at bay.
Growth hormone can help build tissues, and it has a secondary role in lipolysis (fat oxidation or burning). If your goal is to burn fat and high amounts of calories fast primarily, then training in the lactic acid zone is essential for optimal success.
Finally, it has been proven that when athletes feel their second wind in competition, their increased systemic lactate levels occur to readily help fatigued muscles acquire the necessary amounts of fuel to overcome exhaustion. I know many have witnessed and experienced this conditioning effect. Since lactic acid is produced quickly, this makes sense. Creatine's pathways are faster, but recovery periods are longer. Creatine's availability after initial bouts of maximal effort may be compromised quite heavily, so the body has to seek out option b and maintain performance to some extent.
Now, let's find out why lactic acid isn't what you want when the primary goal is to get faster. Conditioning has to take somewhat of a backseat if you are going to get faster, as gene expression for speed will be shifted downward in reducing speed gains. Research and real-world evidence support it. For instance, in a study from 2011 by Majumdar, any predominant activation of the lactic acid system in a sprint would decrease speed. Additional research in 2012 from Wilson identified that there once existed interference effects of development between conditioning and power, strength, and hypertrophy. Along these same lines, prominent research and training expert Dr. Brad Schoenfeld has shared some work showing the same effects between strength and conditioning gene expression. Of course, there is some overlap between the two, and you can improve with both.
So why does this happen? Well, when there is too much intracellular acidity, the enzymes responsible for energy transfer are inhibited, and muscle contractions suffer. Just put 50-75% of your 1rm in a given exercise on the bar and rep out till you feel a burn. You will automatically notice you are weaker, and your muscle contractions have weakened. So obviously, if you are trying to run faster, this is the last thing you would want to create with your movements. The Hydrogen Ion is a by-product of lactate formation that causes the burn rather than the lactate itself. Coordination levels and fatigue also occur, which can really hinder speed output and more.
The final reason why too much conditioning and lactic acid training is counterproductive is that it's not energy system-specific, and cardiovascular and metabolic adaptations or changes in the body happen the fastest. In one of his books, Mike Boyle said that it could take months and even years to make an athlete faster and more explosive. Outside of initial acute speed gains that occur with most athletes, progress tends to be very incremental over training weeks. So why implement training methods that can potentially be a detriment to your training goals?
Also, speed work is "alactic," where energy is supplied for 5-30 seconds at very rapid rates in high volumes before switching over to lactate production. The body has to learn to increase its ability to operate metabolically with this energy system and adjust specific enzyme levels to meet the training demand. Pretty simple.
On a final note, you still have to consider "The Speed Governor Theory", and what I like to call the "Francis Rule." World-class track and field coach Charlie Francis stated that any work below 95% effort was pretty much useless in at least one of his books. He hated the classic lactic acid zones and knew it was unnecessary to maximize his athlete's speed. I have witnessed the same in all of the athletes we have made faster over the years. Even those that rely on the lactic acid system (400m, 800m, MMA fighters, etc.) still need to create a higher speed reserve that they can call upon in training and competition. The only way to do that is to follow everything I discussed above and then integrate specificity when the time comes.
Read More: Does Lactic Acid Really Make You Sore?
#1- Godfrey, RJ. The role of lactate in the exercise-induced human growth hormone response: evidence from McArdle disease. Br J Sports Medicine: 521-525, 2009.
#2-Godfrey, RJ. The exercise-induced growth hormone response in athletes. Sports Medicine: 599-613, 2003.
#3-Majumdar, A. The Science of Speed: Determinants of Performance in the 100m sprint. International Journal of Sports Medicine and Coaching6: 479-494, 2011.
#4-Wilson, JM. Concurrent training; a meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research 26: 2293-2307, 2012.