Throughout my life, I’ve always maintained health to be of paramount importance, even surpassing career aspirations as a need. A healthy body predicates a healthy mind, which is the ultimate derivative of everything else. Even though I would self-proclaim to be knowledgeable about most things fitness, this book has expanded my knowledge even more, which would definitely nudge me to tweak my regime.

The book has brought up a handful of arguments and studies (don’t sit too long, sleep is important etc.), but these are some key points that I found to be really useful.

The Stages of Energy Consumption

With burning fat as the ultimate goal we all aspire to attain, the understanding of how our body draws energy, which eventually burns fat, is important so that we may exercise “correctly” to meet our goals.

At the start of the exercise, we consume ATP (Adenosine Tri-Phosphate), which becomes ADP (Adenosine Di-Phosphate), and the energy generated to break away the single Phosphate Molecule powers our movement. Our body tries to replace ATP as quickly as it can so that we may sustain our energy consumption.

In the first stage of ATP regeneration, the body consumes Creatine Phosphate to produce more ATP. This is why Creatine is a popular supplement amongst athletes, as it gives them a larger reservoir of expandable energy.

In the second stage of ATP regeneration, the body then proceeds to break down glucose through a process called Glycolysis. During this process, a by product called lactate is produced, and it brings the familiar aching of the muscle as this lactic acid builds up.

In the final stage of ATP regeneration, the body then seeks to break down the fat storage for energy.

The whole process from the first stage to the third takes about 30 minutes, depending on the intensity of the exercise. What this means is that doing quick and bursty exercises may seem exertive, and while it does consume a lot of energy, you may not be consuming enough to press the body to break down fats for energy consumption.

Instead, your exercises should be intense and long enough to reach the final stage. HIIT exercises are a good example of such a workout.

The Costly Repair Hypothesis

Our body, which requires oxygen to function, paradoxically kills itself through the process of oxidization. This damages the body slowly overtime.

The Costly Repair Hypothesis posits that by exercising strenuously and intensively enough, you would induce significant amount of damage to the body. In return, a significant amount of repair is done by the body to heal the damage done, and this repair would in a sense “over-heal” the damage induced by the workout, and also heal the damage done when not exercising (e.g. being sedentary).

This over spillage of recovery can only happen when the exercise is intense enough, hence HIIT would be preferable over LISS

Strength VS Endurance Training

While strength training is required to keep your muscles and bones healthy and fit by inducing stress, it’s not as important as cardiovascular health.

When comparing the different permutations: (Cardio + Weights) > (Cardio) > (Weights) > (Nothing).

And when we talk about cardio: (HIIT) > (LISS) , so try to incorporate a mix of HIIT (Which sprints are the best), with some low steady state cardio. It’s important to state that low steady state cardio must be done long enough to compensate for the lack of intensity. HIIT can only be sustained for a short period of time, while LISS can, and must be done longer to achieve the same effect.

Closing Thoughts

You don’t stop exercising because you grow old, but grow old because you stop exercising.

Growing up, I’ve always been a weights person, and never really focused on my cardio. I used to joke that when it comes to Fight or Flight, I’ll always Fight, but after reading these studies, it has changed my view of what “fitness” really means, and it’s not always about having muscles or looking fit, but more toward cardiovascular fitness. Generally, what I hope to achieve is:

LISS/Weights/HIIT/Rest/Weights/HIIT/Rest

To start the week with a LISS, to end the week with a Rest, and to incorporate 2xWeights and 2xHIIT a per week