Each one sounds like it’s going to bring you the body composition changes you might be looking for. Each has a specific target audience. There are diets for those who just want to lose weight. There’s diets for those who want to improve cardiovascular health. And then there are those that promise huge gains in athletic performance, especially in endurance sports.
Let’s sift through some of the most talked about diets in the sports world and look under the hood of each to see if they indeed provide the promise they are selling on the surface.
The Paleo diet touts a way to eat that brings overall health based on our genetics honed through evolution. This is one of the diets that calls us to eat like our cave ancestors did about 10,000 years ago. The argument in favor is that humans evolved to thrive on seeds, nuts, fruits, vegetables and all kinds of wild game and eggs.
It avoids grains, beans, dairy and just about everything that gets grown on a farm these days. And it certainly says to not eat processed foods.
There are certainly benefits to eating more basic foods. However, humans and food have actually evolved in the past 10,000 years. Many cultures have actually benefited from eating beans and grains that are whole and contain their essential fiber and nutrients necessary for gut health and good levels of magnesium, selenium and manganese. Also a lot of western cultures get essential calcium for bone health via dairy products. Restricting these can lead to low bone density, which can be an issue as people age.
This one is popular with athletes recently. This is one of the diets that focuses heavily on restricting carbohydrate intake. Someone on a strict keto diet is going to get about 10% of their calories from carbs and 70% from fats. The other 20% is from protein.
The idea is that by eating like this your body gets much more efficient at utilizing fat for fuel. And as an endurance athlete, being a good fat burner is generally thought of as an advantage in a long race where it can get tough to keep shoving in carbohydrate calories fast enough to sustain a good pace for hours on end.
When carbs are super restricted like this, your body has to do a few things. One is to make ketones (thus the name keto diet) to provide fuel for your brain. Your brain likes glucose. That is it’s main fuel. But it can function on a backup fuel, which are ketones that are a form your brain and your muscles can use for energy.
However, that comes at a cost. For exercise, when you run out of carbs (which is a constant state in a keto diet where you go into what is called ketosis) you need to do something that is a negative to release stored fat for energy. You need to break down lean muscle to then be converted into glucose. That then fuels the fat breakdown chain to release the energy in stored fats in your body.
That means that muscle you are trying to build up is getting broken down to fuel the workouts that you are doing to try to get stronger and faster. That’s not good!
On a keto diet you will end up burning more fat. But it will only make you a bit more efficient at workouts or races that are fairly slow. As you speed up, the whole metabolic process just cannot keep up. A few carbs at that point will indeed get the whole engine firing.
But more importantly is that on a keto diet, you can end up with low nutrient levels. The restrictiveness of this diet eliminates a whole host of foods that provide essential vitamins and minerals needed for overall health.
There are a lot of definitions of this as a tool to get your body into a more balanced state metabolically. The main tenant is to have a big chunk of hours during a 24-hour period where you are not eating. And by doing this it helps your body to reset from an insulin producing cycle where you are having to store away calories that were eaten into a fat burning phase where your insulin levels drop and you start to release stored fats for fuel.
The amount of time that is needed to do this varies depending on who you talk to. Generally it is felt that you need 12-14 hours a day without eating to stimulate that rebalancing of fuel utilization and body composition changes.
There was a study done recently to determine why a lot of marathon runners from Africa are so lean even though they generally eat a diet high in carbohydrates, almost twice as high as the average top level American marathon runner.
So the project looked at a lot of variables in their daily life to see what the answer was. They saw that the runners would eat dinner at a reasonable hour and then not eat anything later at night. Then in the morning they would do an easy moderate length run before they had breakfast (an aerobic fat burning workout). After that they would eat their first meal.
Later in the day they would often do a more rigorous run. Some days it was their very intense speed session that was all anaerobic and carb burning.
The result was that the African runners would have at least 12-hours where they were not eating anything. That was followed in the morning by a fat burning workout before breakfast. That was their intermittent fast. That hyper-stimulated their fat burning engine to kick in and develop. And fat burning is one of the promises of intermittent fasting advocates.
Then later they did their anaerobic sessions. That is also when eating carbs and having them stored in their bodies was essential for good training. Speed work is anaerobic and mostly carb burning.
They developed a very balanced physiology. This enabled them to run fast for their marathons, to eat balanced and to have body compositions that could now be explained even though others thought you had to go Keto to be lean and burn fats!
At this point your head is probably spinning! So many diets, only one body. What is the best for you!
If you have not read it yet, go back to the blog just before this one. It breaks things down to the basics and can help you experiment with what you eat and develop a diet that works for you from the ground up. Experiment until you hit on a way of eating that is both health and fitness enhancing as well as sustainable. Here is that link:
Evolve how you eat so that you continually meet the daily demands of what your body needs to repair, replenish and rebuild. This can change dramatically depending on how you exercise and the age that you are at right now.
And here is something even more important. How you eat each day adds or detracts from your overall health and body balance. Neither the positive or the negative will likely be noticed in one day though. But over weeks and months you can see dramatic effects. The negatives can be weight gain, sluggish energy levels and difficulty concentrating. The positives can be steady energy levels, steady and appropriate body composition and enhanced overall physical and mental health.
If you are coming off a long period of eating habits that you are now seeing detracted from your well being, give yourself a good amount of time to reverse those impacts.
One day of “sticking to the plan” won’t do much physiologically to change your body’s health. However, even one good day gives a huge boost to you mentally. It is one piece placed into the foundation that will become a life of health and good eating!
Join us at Mark Allen Coaching and make your commitment to being your best!
(This is the fifth in a 9-part series of blogs on tips to help you train and race at your best!)
I am the Founder and CEO at Mark Allen Coaching. I am proud to have been voted in an ESPN global poll "The Greatest Endurance Athlete Of All Time." During my multi-sport career I won the Ironman Triathlon World Championship six time, the inaugural Triathlon World Championship at the Olympic Distance in Avignon, France, and at one point in my career I won 21 straight races across every derivation and distance. It was a great career, but that's all it would ever be unless I was able to share all of the experience and methodology we invented long before smart watches, power meters, and flashy uniforms. That's why I started Mark Allen Coaching, as a way to return to others at least the part of the gifts I received.