AMPK – Your Personal Fitness Manager

By Rick Morris

Good managers and directors and invaluable to business owners. They make sure that things get done efficiently and effectively. Just imagine a warehouse full of workers that have no direction or guidance. Nothing would get done!

You may or may not own a business, but as a runner you should still be very concerned with high quality management. More specifically – how efficiently and effectively your running fitness is managed. You may think you’re on your own when it comes to managing your level of running fitness. You do play the major role. You are in effect, the President and CEO of your body. You’re in charge of when and how you exercise. You decide what type of training program to engage in. But, you’re not alone. Did you know that you actually have a built in fitness manager? Yep – that’s right, you have a fitness director that you probably didn’t even know you had. Your personal fitness manager is called AMPK.

AMPK is an abbreviation for AMP-activated protein kinase, which is the technical term for an enzyme that plays a large role in regulating a number of cellular processes that are important to your running fitness. There are a number of improvements your body makes in response to training, including: increased blood supply to your muscles, increased number and capacity of energy producing mitochondria, increase in muscle glycogen and an increase in a number of enzymes that help your body use both glucose and fats to produce energy. AMPK is responsible, in part, for all of those improvements that increase your running fitness and make you a better runner.

One of the great things about AMPK is that it only shows up for work when your body puts in a call for it. AMPK is always there and ready for work but it’s mostly inactive until you need it. What a great concept, a manager that only shows up when work needs to be done! There is one primary signal your body uses to wake up and active AMPK – an increase in your AMP-ATP ratio. You may already know that ATP (adenosine triphosphate) is the substance your body uses to produce muscle contractions. When your muscles contract a phosphate breaks off ATP to form ADP (adenosine diphosphate). In order to make more energy producing ATP, ADP then donates a phosphate group to another ADP which results in ATP and AMP (adenosine monophosphate). During an endurance or high intensity workout, this process happens over and over again, which results in a dramatically increased ratio of AMP to ATP. When your AMPK notices this, it springs into action. Your AMPK then takes steps to improve the efficiency and fitness of your body through the responses mentioned earlier.

That is a lot of responsibility for a lone AMPK. Fortunately, your body takes pity on the poor, overworked AMPK. Studies have shown that endurance training increases the amount of AMPK in your body. The more training you do, the more AMPK fitness managers your body “hires”. One interesting finding is that although the amount of AMPK increases with training, its level of activity actually appears to decrease. Is that because there is less of a workload on each AMPK? That’s one possibility, but a more likely answer is that AMPK only becomes highly active when it’s really needed.

You may have heard the saying – “If you always do what you’ve always done, you’ll always get what you’ve always gotten”. This is a perfect example of that. Scientists believe that if your body is cruising along with little difficulty, AMPK stays inactive. The changes that AMPK facilitated in improving blood supply, building mitochondria and increasing enzyme activity are able to keep up with your training and reduce the need for AMPK activation. AMPK doesn’t get involved again until your body demands it. Since you need AMPK activation to increase your fitness levels, what do you do? It’s really simple. You need to continue to challenge your body to higher levels of fitness. Increase the distance of your long runs. Complete your interval training at a faster pace. Do more intervals with less recovery time. This will further elevate your AMP: ATP ratio and will send a clear signal to your AMPK that it’s time to get to work. AMPK will make sure you are consistently reaching new levels of running fitness as long as you tell it to by consistently challenging your body.