Book Review: Body by Science by John R. Little and Doug McGuff

There are a lot of fitness books out there and I admittedly don’t know anymore where I got this one from, probably some podcast, but it is one of the best I have read, probably because I am a science guy and this one explains fitness and how the body works.

You already get that this is different because it starts with definitions:

Catabolic: Anything that results in the breakdown of the organism.

Anabolic: Anything that results in growth and differentiation of the organism.

Health: A physiological state in which there is an absence of disease or pathology and that maintains the necessary biologic balance between the catabolic and anabolic states.

Fitness: The bodily state of being physiologically capable of handling challenges that exist above a resting threshold of activity.

Exercise: A specific activity that stimulates a positive physiological adaptation that serves to enhance fitness and health and does not undermine the latter in the process of enhancing the former.

To understand what to do you need to understand how the body works and what effects certain actions will have.

I will try to put it very shortly, and you have to read the book to really understand it, but you have a very quick glycolysis cycle that leads to ATP relatively quickly, and the krebs cycle which is a lot more complicated but also more powerful. You need to stress the glycolysis cycle to train the krebs cycle. Call it the support system that needs to improve together with more muscle. But the glycolysis cycle will always be faster, but might just not be enough.

The most fun thing is that this stuff is so majorly complicated. If you really work out and lactate forms in your body, it goes through the liver back to pyruvate and from there glucose, made again available to the muscles either spent directly or stored as glycogen in the muscles directly.

Also, this lactic acid, you also produce hydrogen ions that act on hemoglobin molecules so they have less affinity to oxygen which leads to better osygen delivery to the tissues. Scary eh? It’s called the Bohr effect and btw, high altitude training does not really lead higher lung capacity (I doubt that admittedly, probably a bit too), but to an easier give up of oxygen by delivery molecules.

So why do they talk about importance of high intensity training? Because if you run or walk, you burn X calories, makes no difference. The difference is that high intensity trainings activates hormone-sensitive lipase. Ok, it’s complicated. A lot more depth is in the book.

The second part is that you have slow-twitch, intermediate-twitch and fast-twitch muscles fibres. Normally you only employ the slow twitching fibres and the fast-twitching ones were really built for high emergency situations. The latter really were needed to use every now and then and hence need a week to re-energise and you need to make sure that you push weights over a 45–90 second interval (150 seconds absolute max), constantly (think TUL aka Time Under Load) and slowly, to cycle through all different fibre types. It means you start with a weight that is a bit too light, which will become heavier during the workout, and at best in the last few seconds you continue pushing for 10 of them while nothing really moves.

Proper strength training does exactly the opposite. Rather than recruiting all muscle fibers in tandem, it recruits them in a sequential, orderly fashion and taps the fast-twitch motor units last, after you’ve tapped out all of the other, lower-order fibers. This yields a far more thorough stimulation of your musculature and of your metabolism. There isn’t a rock that’s left unturned. Not only are all fiber types stimulated, but also, because of the tie-in of the metabolic pathways to mechanical movement, you’re involving everything related to fitness in the organism by using this protocol.

You just need to work until positive failure. You should move the weights as slowly as possible, at best at 75–80% of your starting strength, go above the point where you feel you need to quit, continue breathing, and push at the very end for 10 seconds even if nothing moves.

After all, the purpose of the exercise is not to make the weight go up and down; it is to achieve a deep level of inroad, to reach the point where you can no longer move the weight but still keep trying. If you have that degree of intellectual understanding, then you will be able to override the instincts that otherwise would intercede to prevent you from stimulating the production of a positive adaptive response from your body.

If you can push longer than 90 seconds, increase weight by 5–10%.

In the face of epinephrine, hormone-sensitive lipase will mobilize fatty acids out of the fat cells for emergency energy usage, but in the presence of insulin, the action of hormone-sensitive lipase is inhibited. When you perform high-intensity strength training, epinephrine stimulates an amplification cascade of hormone-sensitive lipase, allowing the liberation of fatty acids from the fat cells, to begin the fat-mobilization process. This outcome is a dividend of high-intensity exercise itself, irrespective of calorie balance.

Also, the reason why doing these exercises burns calories long after the exercise is that due to the nature of your workout the energy stores of your muscles are empty need to be refilled.

A mere pound of fat stores an astounding 3,500 calories for delayed use at any time in the future. Because it is dormant tissue, there is almost no metabolic cost for keeping it on the body. As members of the human species, we all owe our existence to fat.

For about 150,000 generations, efficient fat storage was essential for survival, but only three to four generations have seen efficient fat storage lead to obesity.

Also important is that if you work your muscles, the body will try to build up muscle, hence if you have a calorie deficit it will try to get rid of other nutrients (e.g. fat) first. Also the reason that fruits, vegetables and lean meat are better to loosing fat is because the cost of converting those is higher than e.g. refined carbohydrates, a concept known as “thermic cost of digestion”.

In the end, this function holds, no matter what:

Energy intake − basal metabolic rate (determined largely by the degree of muscle mass) + increase because of added muscle through proper exercise + energy cost of activity, including exercise + thermic cost of digestion + heat loss to the environment = fat loss (or fat gain, if energy intake is greater than the energy cost of the listed components).

To loose weight, they suggest the following:

First, eat natural, unprocessed foods. These foods typically have a lower calorie density per unit of weight. Research has shown that humans gravitate toward eating a specific weight-based quantity of food each day.

Second, stay cool. Keep your thermostat down, and wear cooler clothes.

Third, sleep well and sleep cool.

Fourth, avoid stress as much as possible.

Fifth, employ high-intensity exercise.

Good insights I have to admit and the science play allows me to understand and accept their insights better. Let’s see how I think about that in a few months :)