Goal 5 - Raise Your Lactate Turnpoint

Scientific research is a great source of information for running coaches and athletes, but it can also be the cause of some confusion. The role of lactic acid in running is a good example. Back in the sixties and seventies, when I was just learning to run, it was commonly believed that lactic acid was a waste product that caused muscle soreness and muscle fatigue. Nobody had anything good to say about lactic acid in those days. It was just a “garbage” by product that caused nothing but problems. Back then things were really simple - when you became fatigued or started to hurt, just blame lactic acid.

Some years later things got more complicated. Researchers discovered that lactic acid really wasn’t all that bad. In fact they found out that it was actually a valuable source of energy. It didn’t cause the burning sensation in your legs and it was no longer a waste product. Instead it was a sort of transitional product that our bodies converted to additional energy. While lactic acid quit being the culprit, it did still play a role in causing fatigue. Scientists believed that accumulating lactic acid caused a build up of hydrogen ions. These hydrogen ions make the acidity of our blood rise. This rise in acidity was considered a primary cause of fatigue when running at 10K pace or faster.

That made things a bit more complicated for a while. Lactic acid became a substance that was mostly a good thing but was still an indirect cause of fatigue.

Today those pesky researchers are at it again. Now it’s believed that lactic acid plays no role in running fatigue. Quite the opposite - lactic acid help prevent fatigue! The latest research shows that the real culprit in high intensity running fatigue is potassium. Your muscles depend upon an exchange between potassium and sodium to facilitate a muscle contraction. During high intensity the amount of potassium inside your muscle cells is decreased and extra-cellular potassium increases which causes less muscle “excitability” or the ability of your muscle to contract. In simpler terms it causes muscle fatigue. It is now believed that increased blood acidity, which is caused by lactic acid build up, counterbalances the decrease in potassium and helps prevent fatigue.

Wow! - what a trip. In just 30 years we lactic acid went from being a black-hearted devil that causes nothing but problems to a knight on a white horse that rescues us from the evil clutches of fatigue. A change like that can make training properly a difficult proposition - or does it? Has lactic turnpoint training really changed? Not really!

How did we train to improve our lactate turnpoint in the early days? We did cruise intervals at just slower than 10K pace and shorter interval training at or faster than 10K pace. When scientists thought that lactic acid was a source of additional energy, but still contributed to fatigue, did we change training techniques? Nope - still the same type of training. How about today? Since we now believe that the lactic acid helps prevent fatigue, do we care about lactate turnpoint. The answer is both yes and no.

It seems that the rise in blood acidity and the increase in extra-cellular happens at exactly the same time and at the same running intensity - at or near 10K race pace. So - our training still remains the same. Cruise intervals at slightly slower than 10K pace and shorter intervals or compound sets at or faster than 10K pace are still the workouts of choice. Technically these workouts should probably be called potassium turnpoint workouts, but they have been known as lactate turnpoint or lactate threshold training for so long that changing the name will only add more confusion.

Do you even need to do this type of workout as a marathon runner? After all - your race pace is well below lactate turnpoint pace. Blood acidity and potassium build up are not a major factor in marathon pace fatigue. So why do them? If you are a new running and only want to finish your marathon, these workouts could be helpful, but are not critical. If you are interested in improving your marathon performance, racing the marathon or running at a specific pace, these workouts are a very important part of your training program.

One of the most reliable predictors of your marathon potential is your current 10K race pace. If you improve your ability to race a 10K your marathon potential improves at the same time. Why does this happen? Keep in mind that your lactate turnpoint occurs nearly right at your 10K race pace. When you raise your lactate turnpoint (LT) you are able to run faster before reaching your LT. For example say your current LT is at a pace of 8:00 per mile and after a period of LT training your LT pace improves to 7:30 per mile. Now your old LT pace of 8:00 per mile becomes a relatively easy pace. All of your paces adjust at the same time. It is like a sliding scale. Your marathon pace improves along with your LT pace because you are able to run faster while still maintaining the moderate marathon pace.

As I mentioned, LT is best improved by performing a combination of long repeats of 15 to 30 minutes at a pace that is slightly slower than 10K pace and shorter repeats of 800 meters to 2400 meters at or faster than 10K pace. These types of training runs work best because they cause in increase in both blood acidity and extra-cellular potassium. Both your body and your brain are then required to learn to become more efficient at dealing with those changes.

Continue to Improve Your VO₂ max and vVO₂ max

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