Endurance is your ability to run, hike, bike, fight, you name it – for an extended period of time. It’s the maximum pace/speed you can sustain for the duration of said activity before you get tired and have to slow down (fatigue). Endurance is limited by fatigue. So, the goal of endurance training is (you guessed it): fatigue resistance (delaying the inevitable).
What causes fatigue?
- Your body’s inability to meet energy demands (either you don’t have enough reserves or your body isn’t efficiently using what it already has)
- Certain metabolites accumulating or diminishing
- Reduced motor nerve signal
Your brain is the ultimate regulator of your endurance/fatigue (brain always gets final say). No matter what causes the fatigue, your brain will respond by telling your body to slow down. So, endurance is not just about pushing through the pain. It’s about making sure fatigue doesn’t hit you for as long as possible, (thus preventing your brain from slowing your body down).
SO, good conditioning/endurance training raises the limit of how much you can do before that fatigue signal has the brain shut everything down.
What are you training when you train for endurance?
As you might have guessed, your <3 heart <3 is doing most of the work to send oxygen out to the body. The more efficient your heart is at delivering oxygen, the more conditioned you’ll be (probably). The good news: the heart is a super teachable muscle. You can actually train it to pump out more oxygen with each heartbeat (& thus improve delivery to your muscles & thus delay fatigue).
The next piece of the puzzle is how well your muscles utilize that oxygen once they get it. This is dependent on the muscles’ “aerobic” qualities (also very trainable). During any exercise, your brain controls which muscle fibers are being activated and for how long.
Most activities favor a certain type of muscle fiber, and you can train these fibers depending on the adaptation you want (strength, speed, power, endurance, etc). For example, long steady-state training improves the aerobic (oxygen using) qualities of your slow twitch muscle fibers. Short bursts of high intensity train the anaerobic qualities of mostly fast-twitch muscle fibers.
So, good conditioning/endurance training doesn’t target just one system, but rather multiple systems working together. You have to train each system appropriately in order for your body to become fatigue resistant as a whole and reach your true potential as an athlete. The primary systems I’m talking about are the aerobic system & anaerobic system. They are connected. If you only focus your time/energy on one, you’ll eventually hit a plateau and come up with some bullshit narrative that you’re “not built for endurance”.
Moving on! <3
People who have great endurance/conditioning (these terms used interchangeably):
- Can take up and use a lot of oxygen during exercise (Vo2 max)
- Are very efficient in their movements (technique that doesn’t take unnecessary energy AND efficient metabolic processes…they’re efficient inside & out!)
- Can produce and sustain a good amount of energy/output (key word: sustain (lactate threshold))
One last thing for part 1. Stay with me!
Let’s talk briefly about ATP. ATP is a molecule inside every single cell that holds energy. Think of it like your body’s currency (the more intense an activity the more (ATP) expensive it is. So, the faster your body can pump out & recycle ATP, the faster you’ll be able to go for anything beyond like 5 seconds. So, we want our body to be churning out (and properly utilizing) ATP out like a MF so you can go faster longer.
The body takes two main routes to fuel activity (supply ATP):
- Anaerobic glycolysis – great for high intensity because this pathway can supply more ATP immediately.
- Aerobic – produces much more ATP, but it’s a slower-process & therefore better for long-duration stuff.
IN SUMMARY: improving endurance/conditioning is about training the different metabolic processes & systems (how your body produces energy to get ‘er done), not about redlining as long as you can every workout*.
*Should you redline as hard as you can sometimes? Hell yeah! But it’s probably less than you think.
🙂
That’s all for right now! Stay tuned for PT. 2 where we’ll cover the science a bit more and also start the discussion of what this stuff actually looks like when applied in real life!
Thanks for being here!