Contrary to popular belief lactic acid build up does not cause sore muscles. According to L. Bruce Gladden, a professor of health and human performance at Auburn University, "lactic acid is cleared from the muscles within an hour of exercise" he said. "You get sore one to three days later. The time frame is not consistent, and the mechanisms have not been found."
Researchers have determined that lactate isn't even the cause of muscle burn as once thought. Our muscles use energy in the form of adenosine triphosphate (or ATP), and in the process, hydrogen ions or protons are released. If you exercise at a low or moderate level, the protons are soaked up by other chemical reactions, but if you do heavy or prolonged exercise, the protons accumulate in your muscles and that's what makes them burn.
By increasing your endurance you can increase your body's ability to use protons faster, thus preventing muscle burn for more prolonged exercise sessions.
He goes on to say, "Your lactate threshold is the pace at which aerobic metabolism can't keep up with production of pyruvate from glycolysis and is the fastest pace above which lactate production begins to exceed its removal along with blood lactate concentration beginning to increase rapidly."
In simpler terms, it is the fastest pace that you can sustain aerobically without going anaerobic. This is why lactic threshold is sometimes referred to as anaerobic threshold.
All pretty technical stuff and I even have a hard time putting together and understanding a lot of the scientific and biological terms. Some of it probably didn't need to be said but I find it all very interesting and the whole point I'm trying to get across is the importance of lactate threshold training by using tempo runs while giving you and I a little understanding of why.
To sum it all up, increasing the lactic threshold will give you more endurance to run longer at a faster pace which is one thing we all wish we had more of during a race.
Tempo training varies slightly depending on race distance and the next article will be how to use tempo runs to effectively increase lactic threshold in half and full marathon training. In another future article, we will see how to use them in training for shorter races as well.
Enjoy every step.
Al