The Fitness Junction

This week:

• Knowledge Corner: Endless Endurance

• Monthly Challenge Update: May Yoga-a-thon

• Meme Center: Pool Aerobics FTW

Knowledge Corner: Endless Endurance

Last month, I discussed the three energy systems the human body uses to power cardiorespiratory endurance. Check that out if you don't recognize any of the terminology I use below. The focus today is the oxidative system, aka the aerobic system. This is the longest lasting energy pathway, providing the majority of ATP for activities lasting over two minutes. For steady state cardio, which includes activities like running/biking/rowing/swimming at a sustainable pace, the oxidative system is the primary source of energy (~70% of ATP). By training for aerobic endurance, we can raise our baseline cardiorespiratory health and increase our performance across all facets of fitness.

Oxidative system training has two primary mechanisms for improving endurance. The first is through mitochondria - the powerhouse of the cell! Aerobic exercise signals to your body to create additional mitochondria and improves their efficiency - leading to increased energy production. The second mechanism is by increasing the strength of your heart, specifically its stroke volume. Stroke volume is how much blood your heart pumps out each beat. With a higher stroke volume, your body can deliver more oxygen and energy substrates (nutrients needed for energy production) to muscles and removes waste products faster, like CO2 and lactate.

These mechanisms are beneficial to all three energy systems. Even if your training focus is on sprints or weightlifting, an improved aerobic system will be beneficial to your performance. The oxidative system is essential to speeding up recovery. It does this by removing waste products and buying time for the energy stores of the ATP-PC and glycolytic pathways to return to baseline for the next set. This is why aerobic fitness is considered foundational for cardiorespiratory endurance and overall performance.

The key metric to keep in mind when planning your aerobic endurance training is your heart rate. More specifically, you want to target your training to spend 20+ minutes at certain percentage of your max heart rate. To improve aerobic capacity, 60%-75% of your heart rate max is ideal. This range is often referred to as "zone 1" cardio training. There are multiple methods of determining when you're in zone 1 but I prefer the talk test. The talk test measures how easy it is for you to converse while exercising. If you can get short sentences out, but are uncomfortable talking for more than that, they're you're in zone 1 and should sustain that pace for aerobic training. Doing the talk test with yourself is a simple way to gauge how intense your exercise is and adjust your pace accordingly to meet your training goals for that session.

There is minimal difference in the effectiveness of improving aerobic fitness between running, biking, rowing, and swimming. If you are training for a specific race or event, then it's best to focus on that exercise. If not, then I recommend you mix up your modalities to keep your body guessing and avoid over-use injuries. Also, don't forget that activities like basketball, martial arts, soccer, and moshing are also great aerobic training - and a lot more fun than standard cardio. Even lifting weights can help train your oxidative system if you maintain a high tempo (e.g. super sets, triple sets, circuits, and shorter rests). So take your pick and don't skip cardio!

Sources: National Academy of Sports Medicine, National Strength and Conditioning Association, and American Council on Exercise

Trivia

How many fat calories does the average person burn in an hour of steady state cardio?

• A. 125

• B. 112

• C. 98

• D. 69

May Challenge: Yoga Once Per Week

I knocked out this flow session with YouTube legend Adriene for my first round of yoga. Always a great way to start or end your day! And free resources like YouTube makes it easy to do, even if you have no experience.

Meme Center:

Trivia answer: A. 125. Your total calorie burn during an hour of steady state cardio would be ~180, with fat making up 70% of that. Fun fact, you burn more total calories during moderate or high intensity cardio but your burn a higher percentage of fat calories doing low intensity (steady state).

Thank you for reading this week's Fitness Junction! If you aren't already, subscribe here and share the newsletter with anyone you think will enjoy it. Click the button below to learn more about Natural Function Fitness and our services.