Everyone has different goals in fitness. Proper goal chasing is where specificity and efficiency come into play. Kobe Bryant did not become one of if not the greatest basketball player of all time by running laps around a track all day or bench pressing a barbell all the time... Would this have helped his fitness? Sure. Does it mean it was the best approach to accomplishing his goal of winning multiple championships? No.
In this post I want to discuss how our bodies utilize certain fuel options in certain heart rate zones. After reading this you should be able to decide what type(s) of endurance training fits your goals the most. I've gathered some foundational information on this and will lay it out for you plain and simple.
Note: All content comes from reliable sources (peer reviewed and backed) and will be listed at the end of the post.
Before we figure out what type of training is best for certain situations, lets run through some of the basics...
2 Types of Training
Aerobic Training - continuous exercise fueled by the oxygen from the air you breathe
Anaerobic Training - spurts of high-intensity efforts fueled by energy you have stored
Heart Rate Zones
Zone 1: 50-60% of your HRmax (Max Heart Rate)
Light & enjoyable exercise, recovery, very easy
Roughly 85% of burnt calories come from fat
Zone 2: 60-70% of your HRmax
Comfortable intensity, feel warmed up, maybe a light sweat, able to hold conversation
Roughly 65% of burnt calories come from fat
Zone 3: 70-80% of your HRmax
Above average intensity, starting to feel some workload, controlled fast breathing
Roughly 45% of burnt calories come from fat
Zone 4: 80-90% of your HRmax
Tiring, heavier breathing, difficult to hold conversation
Carbohydrates is the main fuel source
Zone 5: 90-100% of your HRmax
MAX effort, heavy breathing, unable to hold a conversation
Carbohydrates is the main fuel source
In Zones 1 and 2, your body uses fat as the main fuel source. As you progress towards Zone 5, your bodily will make a significant swap over to carbohydrates as its fuel source. Additionally, the closer you are to Zone 1 the less taxing the exercise is on your body and less chance you have of acquiring an injury. What does this tell us and do you think you are fueling properly for how you currently training?
Lets create a couple of scenarios to help:
Client 1
Male Age 55, wants to lose weight (primary goal) & doesn't want to get injured, has a history of running, but hasn't run in 5+ years..
Suggestion: Implement 3-4 bouts of regular Low Intensity Steady State cardio (50-70% of HRmax) per week to his current training plan.
Why: Sustained cardiovascular activity that stays in Zone 1-2 has a heavier focus on burning fat as fuel. Exercise of this sort is also less taxing on the body, creating less opportunity for injury.
Fueling: Having a balanced or low carb diet seems best, as his body will use fat as its fuel source the most.
Client 2
Female Age 25, interested in a triathlon personal record (primary goal), previous college swimmer, also wants to lose weight.
Suggestion: Implement a triathlon training program with training variability in HR Zones. Since her primary goal is to improve performance, we want to have easy, moderate, and hard intensity training days. Weight loss will occur as a secondary goal.
Why: We want to focus on both goals, but the triathlon PR is the primary goal. While 50-70% of HRmax is ideal for fat loss, fat loss still occurs above Zone 2 at lower percentages due to your body's preference for carbohydrates when doing higher intensity work. Thus, fat loss will still occur during the overall training phase.
Fueling: Make sure enough carbohydrates are consumed to fuel her efforts. Her body will utilize stored carbohydrates on days with higher training intensities.
Does this bring up any ideas for your own training program? I think my whole point with this post was simply to say specificity and efficiency are important and should not be overlooked. Having a specific and efficient program creates the best opportunity for you to be successful. Your training program should be specific to you, your goals, and your situation.
If you want to talk about your own training program or how you can make some adjustments that best suit you, shoot me a note and let's discuss!
See you next post!
Andrew
Post Resources:
Source 2: https://www.healthline.com/health/fitness-exercise/fat-burning-heart-rate#_noHeaderPrefixedContent
Source 3: https://www.mountelizabeth.com.sg/health-plus/article/fat-burning-zone-heart-rate-to-lose-fat