Last time, we talked about the difference between PUSHING and PULLING to raise your racing/objective paces. Most people intuitively grasp that pulling (going harder than race pace) works. “Going hard to learn to go hard” makes SENSE. Therefore, I’ll save the deeper discussion about pulling for another blog post.
Today, let’s talk a little about how pushing (training at a SLOWER than goal pace) works. But first, some basics.
Training Basics:
- Think of your body like a machine. You have lots of structures (heart, lungs, muscles, etc.), and lots of functions (the chemical makeup of your blood, cells, etc.)
- In order to make a specific structure or function more capable, you need to stress it, and reduce the stress (recover), and then your body will adapt that structure or function so that it won’t be as affected by that stress the next time.
- Thus, the process of training is to stress specific structures and functions in order to make them adapt to become more capable of reaching your goal.
Physiology Basics:
- Muscle needs energy (in the form of ATP) to contract repeatedly.
- That ATP comes mainly from two systems: Anaerobic (“without oxygen”), and Aerobic (“with oxygen”), and comes from two main substrates: Carbohydrates (sugar), and lipids (fat).
- At lower intensities, more oxygen is used, and more fat is burned. As intensities get higher, more energy comes from anaerobic sources, and more sugar is burned.
- Anaerobic and Aerobic contributions are 50:50 at races that are about 90 seconds long, and aerobic contribution significantly increases as races get longer (in a 10 minute race ~90% of ATP comes from the aerobic system). Thus, the aerobic system is the focus of most endurance training.
- You can think of the aerobic system as being made up of three important things: 1) The transport of OXYGEN to the muscle, 2) the transport and storage of FUEL (sugar and fat) to/in the muscle, and 3) BURNING the fuel and oxygen to make ATP.
- While the anaerobic system can ONLY burn sugar, the aerobic system can use fat or sugar.
- Even the most lean of us has nearly unlimited amounts of fat stored in the body, but we have a very limited amount of stored sugar.
- So when we’re training for an endurance sport, we’re usually trying to stress the systems that:
- Deliver more oxygen
- Use more oxygen
- Burn more fat
What pushing does:
- As we discussed last time, there are some advantages to pushing just because of what it ISN’T. Pushing ISN’T incredibly stressful (it requires comparatively little recovery), so you can do a lot of it. Pushing ISN’T stressing our ability to go hard (no high heart rates, no sympathetic nervous system stimulation), so pushing well allows us to be ready for really hard workouts.
- Pushing (done well) IS very stressful to the mitochondria (the only place oxygen is used), and preferentially stresses fat burning structures and functions.
How to push the best:
- At a certain point (around the middle of Z2), your body is burning its maximum percentage of fat, and thus maximally stressing the “base” systems of burning fat.
How to push the worst:
- If you go harder than L2, you start to preferentially burn more sugar, which LESSENS the stress on your fat burning systems, thus slowing down your progress.
- Harder than L2 also wrecks the signal:recovery ratio, meaning that it takes longer to recover from the same amount of stress.
- Lots of time ‘kinda pushing’ in L3 actually SLOWS DOWN your progress.
- Thus, it’s actually best to go EASIER to progress the fastest when pushing.
How pushing makes you faster:
- Let’s go back to our athlete AC from last week’s post. She currently can run 6 miles in one hour (10:00/mile), but wants to run 9:00/mile for an hour.
- By spending a lot of time in L2 (for her, let’s guess 12:00/mile), she will maximally stress the systems of oxidative lipolysis (fat burning using oxygen).
- As a result, at her race pace she’ll be 1) Burning less sugar, 2) Producing less lactate, and 3) Burning more fat.
- Because she’s burning less sugar, she won’t have to slow down as sugar stores get low. Because she’s producing less lactate, she won’t have to slow down as her muscles get acidic.
- Thus, she goes FASTER by training SLOWER.
- Additionally, because her fat burning systems are getting stressed, her Z2 pace improves to 11:00/mile. And then 10:00/mile, etc.
In summary:
Why run easy:
- Leaves energy for hard days.
- Stresses the mitochondria maximally.
- Is the most workload for the least recovery.
Why run hard:
- Stresses the cardiovascular system (oxygen delivery to the muscle).
- Works best on mechanics.
