Talk Nerdy to Me: 5 Biochemistry Facts that You Can Integrate into Your CrossFit Workouts

I’m in the home-stretch of a biochemistry course that I signed up for this fall. I have to say that this course (right up there with anatomy and physiology) was one of my favorite courses that I’ve taken. All of those small, pain-in-the-A details that we are forced to learn in the basic chemistry and physics classes all came together nicely along with biology in a fascinating class that can really be applied to what our bodies do every day in our CrossFit boxes. Without going into too many details and putting you all to sleep, I narrowed this post down to 5 interesting facts about the human body that you can think about and apply during your next training session. Here you go:


1) Enjoy your morning cup O joe. Caffeine is a multi-functional pre-WOD supplement. You have 3 primary hormones in your body that we will focus on during exercise or lack-thereof: insulin, glucagon and epinephrine. At least one of these hormones is active in your body at all times. Caffeine stimulates epinephrine and glucagon using a 2nd messenger in cells called cyclic AMP (cAMP.) Caffeine inhibits the enzyme that degrades cAMP, so your “go” signal builds up and lasts much longer than without caffeine.

Why do we want epinephrine and glucagon active in our bodies?

  • Energy for “Fran” and “Helen” – it increases glycogen breakdown and glycolysis
  • Who DOESN’T want to lose fat – it increases fatty acid mobilization
  • Prep for action and improve circulation so that you can breathe easier – it increases heart rate, blood pressure and dilation of respiratory passages

2) Sit down between lifts. ATP is your energy currency, but humans only have a tiny amount in their bodies. It needs to be regenerated quickly for short rep, heavy lifts. This is a job for creatine phosphate (CP.) CP can replenish ATP within a matter of seconds, which is what we all want! For this to happen effectively, take a seat in between heavy sets. You only need a minute or 2 but your muscles will thank you. Allow your muscles to relax and let the rephosphorylation begin!


3) It’s OK to work out in the fasted state, sometimes. I’m going to talk about glucagon again. After you wake up from a restful night’s sleep, you are in the fasted state. The active hormone in your blood is glucagon. Let’s say you are 10 – 15 minutes into your 30 minute AMRAP. You are now reaching deep into your glycogen stores for glucose for your muscles. Sidenote – High carbohydrate intake leads to filling of glycogen stores. When your glycogen stores are full all the time, excess glucose is then stored as fat, so we WANT our glycogen stores depleted after a hard WOD, or we’ll keep getting fatter (which is America’s biggest health problem, pun intended.) Glucagon allows you to use glucose from your glycogen stores for energy. When those stores begin to run low, your body turns to fat mobilization, yay!!


4) But it’s not a bad idea to maintain high concentrations of amino acids during high intensity exercise. If you work out in the fasted state, your body turns to another pathway, gluconeogenesis, for fuel. This pathway can potentially break down your muscles to get to the amino acids for energy. Avoid muscle wasting. Have a small protein shake or supplement with amino acids before your kick your WOD’s ass on an empty stomach.


5) Not once did I hear the phrase “lactic acid.” Lactate is your friend. Lactate is formed during intense exercise when your muscles can’t get oxygen fast enough. Lactate is then transferred from your muscles to your liver and converted back to glucose (recall, glucose is your fuel for almost all CrossFit-style WODs.) Even better is the fact that when lactate is formed, it takes up a proton, which actually makes your muscles LESS acidic and helps you keep on executing those wallballs beautifully. Main point: lactic acid is not why your muscles hurt.


That sums up my nerd talk for the month. Drink your morning cup of java, take your aminos and thank your lactate.


Leave a Reply