24. First Principles of Fitness

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    Happy Tuesday everyone!

    Last week I talked about the importance of focusing on the basics when it comes to health and fitness. I emphasized the importance of avoiding optimization until you've built a strong foundation.

    But what are the basics?

    Physical fitness, like many things, has its own first principles. If you understand the underlying principles then it becomes way easier to make sense of fitness information and get the results you want.

    The application of these principles will vary somewhat depending on your goals but let's say you mostly care about general fitness and longevity. Plus, maybe you want to lose a little weight and gain some muscle too :)

    To begin, it helps to have a rough understanding of what you're trying to accomplish and work backwards.

    Am I Fit?

    Fitness is such an abstract term it almost doesn't mean anything. There are thousands of physiological and biological indicators of fitness but most of us don't have the time or ability to measure them all.

    As a starting point, however, there are really three elements of fitness that matter:

    1. Musculoskeletal Health - bones, muscles, joints, connective tissue
    2. Cardiovascular Health - heart, lungs, arteries, veins
    3. Metabolic Health - energy systems, mitochondria, fat & carbohydrate utilization

    If your goal is general fitness, you will want to structure your activities around these three elements. By focusing on these areas you will improve your energy and pain levels, your overall physical capabilities and resilience, as well as your aesthetics.

    How do I get fitter?

    The obvious next question is how do I improve in these areas?

    While there are many factors that impact your physical fitness, to make things simple, let's focus only on exercise principles and set aside adjacent topics like nutrition, recovery, sleep etc.

    Musculoskeletal Health

    Exercise Principles

    When it comes to musculoskeletal health there's a few high leverage areas to focus on:

    • Postural Endurance
    • Strength and Hypertrophy
    • Mobility

    Postural endurance is a measure of how well your stabilizing muscles maintain correct joint position while moving. Many injuries occur because of weak or fatigued stabilizing muscles. When you are unable to correctly stabilize and position your joints you are far more likely to add too much load to tissues that can't sustain it.

    Strength is a measure of how much load your tissues can withstand and hypertrophy is increasing the size or length of these muscles. Building strength and growing muscles are not strictly correlated however both are important to overall fitness.

    Building proper joint mobility is important because it will enable you to move correctly and safely while under varying degrees of load. If you can't mobilize your joints correctly, you limit overall function. Plus, you run the risk overloading tissues and causing injury.

    How to train?

    To achieve the best results you need to stimulate your musculoskeletal system in three ways:

    1. Move a lot
    2. Lift moderately heavy things frequently
    3. Lift very heavy things (for you) consistently

    In general you want to move around a lot and make sure every joint is going through its full range of motion. By lifting moderately heavy things frequently you build muscular endurance and maintain muscular size. The only way to become stronger is to safely load tissues at 80% or more of their max capacity. This is done by lifting heavy things.

    Whatever your exercise routine it should include every form of stimulation to some degree.

    Cardiovascular Health

    Exercise Principles

    When it comes to cardiovascular health you're trying to improve the strength and capacity of you heart, lungs and vasculature. In practical terms, your cardiovascular fitness will be determined by the following:

    • Anaerobic Power (work output for 30 - 120 seconds)
    • Aerobic Capacity / VO2 max (work output for 3 - 12 minutes)

    In order to improve your anaerobic power and aerobic capacity you must stress your cardiovascular system. This stress is what drives adaptation.

    How to train?

    The only way to improve cardiovascular health is to push your heart rate to the max or close to the max. How long and how often you do this will depend on your goals but if you're not getting your heart rate at or close to its limit then you will not gain any benefit.

    Usually this looks like sprinting, rowing, burpees, kettlebell circuit etc. where you're not resting and pushing hard. A very rough calculation of your max heart rate is 220 minus your age.

    Metabolic Health

    Exercise Principles

    I covered this topic in a bit more detail in another issue however the main thing to understand is that you want to make your body as efficient as possible at using the energy sources available to it.

    The best measures of your metabolic health are:

    • Your ability to preferentially burn fat
    • Your mitochondrial health

    Ideally, you want to rely on fat as an energy source for as long as possible because it is the most energy dense and therefore efficient macronutrient. Your mitochondria are organelles in your cells which are responsible for almost all energy utilization. These organelles should be dense where appropriate and as efficient as possible.

    How to train?

    One of the most effective strategies for improving metabolic health is what's called zone 2 training. Zone 2 training is exercising hard enough where you can still have a conversation but if you pushed a little harder wouldn't be able to. For many people this is a faster jog or bike ride.

    If overall fitness matters to you then you'll want to start incorporating several longer zone 2 training session every week.

    Do What Works For You

    There is a massive amount of complexity involved in improving your physical fitness in each of these areas. Fortunately the basic principles for each are relatively simple.

    At the end of the day it all comes down to how you want to apply the principles, your specific goals, what's fun for you, and what's sustainable.

    Get after it!

    Nick


    © Nick Nathan, 2022