Cardio for CrossFit - Build your engine!

Recently at CrossFit Widnes we added a new speciality class to our timetable, a class which many
members have been asking for. With members continually growing and members
wanting to work on weaknesses it was a no brainer.

So what is aerobic capacity?

This is the ability of the heart and lungs to deliver oxygen to the muscles at any given time frame. An
example of this is the body’s ability to take in and use oxygen to improve aerobic performance.

So how is this related to CrossFit workouts?

So here’s a little bit of science, there are 3 energy systems we cover in CrossFit:

ATP-PC (anaerobic) = High power, short duration 0-10 seconds
Glycolytic/ Lactate = Moderate power, short duration 30-90 sec
Oxidative (Aerobic) = Low power, long duration 90 sec +

Note: In very few circumstances is just one energy system in use. To make understanding these
energy systems clear let’s use the example of the experience many of us have had, which is anything
longer than 30 seconds on an Assault Bike.

At the start you are at a sprint start and your power output is at its peak , it’s the ATP-PC system
which provides this immediate energy and functions without oxygen, this usually lasts for around 10-
15 seconds and from there intensity and power output drops off.

So this is the system we are going to focus in more detail today. The ATP-PC system:

When we want to lift something really heavy we call upon the ATP-PC system.

ATP-PC is the path to instant, raw power, but it doesn’t hang around for long. It’s our first choice for
immediate energy we can tap into it for 10-15 seconds. ATP already present in the muscle is used up
and then reproduced by the breakdown of creatine phosphate (that stuff we buy online), this allows
us to shift big weights, run fast and then it runs out. Usain Bolt, Rory Mcilroy and Matt Fraser all
have to engage their ATP=PC system to perform at a high level.

Most ATP workouts can be easily done through EMOMS at 75-90% of 1RM for 8-12 minutes or a
barbell complex works well too.

So that concludes a brief insight to one of the three energy systems we cover in CrossFit, part two
coming next week.

In the meantime if you would like to find out more about our CrossFIt Cardio class or would like to
try it out for yourself head over to our website and register using code FIRSTFREE to attend your first
session for free. Every Saturday at 9.30am!

Coach Aimee