[et_pb_column type=”4_4″][et_pb_text admin_label=”Text”]Chris Hinshaw, endurance coach to the fittest man and woman on earth, founder of the Aerobic Capacity program, and second place finisher at Ironman Hawaii in 1985 came to Charleston in August.
This is the second part of a seven part series on how to improve your cardio taken from Coach Hinshaw’s seminar. You can find the first part, Be Deliberate with Your Rest, here.
Part Two: Danger, Lactate Ahead
What are Energy Systems?
This is going to get a little nerdy but understanding the physiology will help you improve your cardio, so bear with me.
Our bodies have multiple energy systems available to cause a contraction in our muscle leading to movement. Broken down to their smallest pieces there are 10, but those 10 are really just varying combinations of three main systems.
The Creatine Phosphate (CP) Energy System
The energy pathway that creates the largest most powerful contraction is known as the Creatine Phosphate (CP) pathway. Phosophocreatine molecules are stored in the muscle cells and used when the demand on a muscle is extremely high.
This pathway only lasts for about 10 seconds but it allows us to use nearly all our available muscle cells. We use our CP pathway for things like sprinting and heavy barbell work (in the 1-5 Rep range).
The CP pathway ‘burns clean’, meaning there are no byproducts from the reaction that contribute negatively to our performance. This is important to remember, I’ll explain why in a moment.
The Aerobic Energy System
At the other end of the spectrum is our aerobic pathway. As the name suggests this is the energy system that requires oxygen to operate. Given it’s name and fuel source (oxygen) you would think this is the most important system to understand when it comes to improving cardio, but it’s not.
As we breathe our body creates usable energy through a series of reactions known as the Krebs Cycle. The benefit of the aerobic pathway is that we can sustain output for hours instead of seconds. However, this pathway can’t produce nearly the same force as the CP pathway.
It’s also another ‘clean burning’ fuel source.
The Glycolitic Energy System
The system that bridges the gap between these 2 is known as the glycolitic system. This system is good for about 120 seconds of output. It isn’t quite as strong as the CP system but it’s much stronger than the aerobic system.
The lactic system operates by breaking down glycogen stored directly in the muscles we’re contracting. As that glycogen is converted to energy we’re left with a muscular byproduct known as lactate (technically hydrogen ions and pyruvate which form lactate).
Lactate by itself is actually helpful. When lactate is formed our body can easily clear it from our muscles (its consumed by type I muscle fibers as fuel- more on that in the next post) allowing continued function.
However, if intense exercise continues at the same output we cannot remove enough lactate and our muscles become acidic from the buildup of hydrogen ions, effectively shutting the muscle down. This is what’s known as training above ‘Lactate Threshold’ and it’s why this energy system is by far the most important to understand and the most dangerous to our performance.
Lactate Overload- Slowdown or Shutdown
If you are above lactate threshold you have about 90-120 second to choose 1 of 3 options:
- Slow Down- You can slow the pace at which you’re moving which means fewer muscle contractions, and therefore less lactate. The decrease in new lactate allows the muscle to clear the excess hydrogen. This also allows our aerobic system to take over some of the work our glycolytic system was just doing.
- Finish- If you’ve ever been a track athlete or witnessed a horse race you’ve seen a sprint to the finish line. That sprint is athletes pushing deep into their glycolitic system. They’ve been running just below lactate threshold for most of their race (distances over 800M), leaving just enough stored energy for one final push. They have to time this final push perfectly. Too early and they’re muscles will begin to shut down as lactate accumulates (you’ve probably seen athletes who seem unstoppable only to slow to a crawl before the finish line). Too late and they didn’t use all the resources they had available.
- Shut Down- If you don’t choose one of the two previous options your body chooses for you. Have you ever been doing a really hard HIIT workout (CrossFit included) and you’re forced to stop mid set because your muscles are burning so badly? That is accumulation of lactate in action. Your muscles simply cannot operate once they become too acidic- so they shut down.
Understanding and controlling lactate is vital to improving your aerobic capacity. Unfortunately our lactate threshold varies from movement to movement. That means there is no formula to figure out how hard you can work, or what heart rate you can maintain, and still stay below lactate threshold.
However, with lots of training and practice it is possible to FEEL when you’re training above lactate threshold. There’s a change in your breathing, a slightly acidic taste in your mouth (seriously), and muscular burning.
Your facial expressions and movements will change as well, which is why working with a coach is hugely helpful when doing lactate threshold training.
The lactic system is powerful but dangerous. If you can learn to feel when you’re above lactate threshold your overall cardiovascular engine and stamina will improve dramatically.
**Part 3 will be released next week and focuses on our muscle fibers. Sign up for our email list below so you catch the next one in your inbox.