Forget The Carbs Before A Race: Research Supports Diet High In Fat Improves Endurance
By admin
Even if you’re not training for a race, you’ll want to know this. It’s interesting stuff. Just go with it.
You’re training for a race (hypothetically speaking) and the one nutritional element that you rely on is what?
Carbohydrates.
Everyone is familiar with the popular pasta night before a big race to help fill your body up with glycogen, the fuel your body uses to get you from the start of the race to the finish line. Right?
Well, what if we have it all wrong?
I ask because my training has been off this season. My runs weaker, my paces slower… what gives?
I spent some time thinking about what’s different (a lot during this particular run!). And for me, my macro-nutrients have changed (intake of carbs/protein/fat), and I don’t think for the good.
The Fuels Of Your Body
Think about this for a second…
The body has two main sources of fuel:
Glycogen (this pretty looking molecule I drew for you):
and Fat:
Energy… did you know that’s the point of fat? To keep energy reserved should we need it (think famine).
But when it comes to fueling workouts, fat is predominately used during lower – moderate intensity workouts. Your body doesn’t want to let go of it if it doesn’t have to. <— Damn!
Which is silly because there is practically an unlimited amount of energy in your fat to have you running for days and days and days!
But glycogen… that’s different.
It’s kept in limited supplies in muscle, often depleted in about an hour after starting a workout. Yet it’s what your body relies on and it’s what we have grown accustomed to focusing on for our endurance workouts.
That’s why many of us squeeze a gel (or chews) every 5-7 miles during a run… to replenish our glycogen so that we don’t hit a wall. Bonk.
If you’ve never bonked, you’re lucky. Basically, the body gives up and no matter how much your spirit wants you to keep pushing, your body says enough is enough.
But what if we could make it so that we don’t rely on glycogen? What if we could teach our bodies to use all that fat we have to fuel us from start to finish?
Not only would we not have to worry about bonking, but we would also train our bodies to burn more… BODY FAT.
And seriously, we all know it’s annoying as all get out to try and squeeze a GU during a race when you’re out of breath and just concentrating on not tripping over your own feet. It takes skill friends. Real skill.
Train To Burn Fat
I have several friends who are crazy awesome runners and have spent months, some even years, training their body to tap into their fat stores.
You can do this by something called low heart rate training. It works, and if you like to run at very slow speeds for a very long amounts of time, then it might be something to check out. Those that follow it often see new PRs being set (personal records) and no longer fear bonking.
For me, I love speed. I guess you can say, I have the need for speed. But I would also love to use my fat more instead of the limited sugar that is hiding in my body.
I want the perks that my LHR friends have seen, that’s fair right?
And not just because I want a 6-pack, but because science shows that having the diet I am about to share with you may help increase endurance abilities, by as much as 20%.
Just think, if you eat your beets AND follow such a diet, then your endurance may skyrocket! <— Maybe not, but that would be awesome.
I’ve got a half marathon in about 30 days and I am really aiming for a PR, now is the time to start putting my head down and really focusing. I’ve trusted my training program, now it’s time I get my nutrition right.
High Fat Burns More Fat
It makes perfect sense… if you eat a high carb diet, which a lot of runners do, you’ll naturally have a lower fat and protein intake. Right? You can’t have a high carb AND a high fat diet.
If you opt for a high fat diet, you’re carbohydrate intake will naturally go down too.
The body is pretty smart, and it adapts to what you give it.
Carbs are easy to digest which is why it’s the go to source if your body had it it’s way. But should you cut carbs, and give it something else, the body will learn to adapt. Through something called ketosis (I actually did my senior thesis on this), the body breaks down fat to use as energy.
Well, studies, show that a diet high in fat can help your body…
BURN FAT.
Not only that, but in comparison to a high carb diet, there is evidence to support that a diet high in fat (over 35% of daily calories) can actually improve overall endurance performance.
Let’s take a look.
What The Science Proves
- In a study published in The International Journal Of Sports Medicine, 7 well-trained runners were placed on 2 diets where their endurance capacity and VO2max was studied. For one month, they were on a low-fat diet (18.4%), then they had a month of a normal “washout period” diet where their diet was comparable to normal Americans (32%) and finally they enjoyed a high fat diet (42%). During all periods the protein intake was kept the same (15%) resulting in a change in just carbs and fat intake. While there was little difference in performance after the low fat diet, the high fat diet results in an endurance increase of 21%.
- A 1999 study on cyclist found that being on a high fat diet after just 5 days altered the body’s metabolic process. During this time, the body changed from carbohydrate to fat oxidation during exercise. The body quickly adapts to what it needs! Performance was based on a timed 40km, where performance was not significantly different between those on a normal diet and those on a high fat diet (69%). Side note: I would have liked to see instead of a timed distance, if their overall endurance had been affected.
- This study, from The Euro Journal Of Applied Physiology and Occupational Physiology, studied athletes on a high fat diet for 2 weeks. What they found was that those on the diet, had an enhanced resistance to fatigue and were able to exercise for substantially longer periods of time. Almost twice a long!
- And finally, a pretty convincing rat study. Rats were placed either on a low carb diet, high carb diet or normal diet. After 1 and 5 weeks the rats were placed on a wheel and run as long as possible. In both situations, the low carb rats ran longer by 5 minutes. Other observations I can’t help but share include: the LCD had lower muscle and liver glycogen content, decreased rate of glycogen breakdown during exercise, decreased lactate production, and elevated blood ketone levels. The study revealed that muscle is able to quickly adapt to dietary changes to spare the little glygcogen levels available. Cool, huh?
As you clearly see, all of these demonstrate that the body is A. Fast to adapt to dietary changes and B. That a HFD (high fat diet) influences endurance.
But does it influence speed?
Not likely. Increasing speed comes from training and building fast twitch muscle fibers. That comes from dedication and pushing your body during workouts. And with energy, high intensity does seem to react better with carb heavy foods.
Per a study at the University Of Kansas State:
“We and others have observed that although fat oxidation may be increased with a high-fat diet, the ability to maintain high-intensity exercise (above the lactate threshold) seems to be compromised or at least indifferent when compared with consumption of more carbohydrate.”
Long distance running, fat is good. But for intense training, carbs may very much still be your friend.
Foods High In Fat
SO what does this mean?
Of course, everyone is different and reacts differently to nutritional changes.
For me, I went almost 5 years on what is considered a low carb diet, and I saw great results (not purposely, I just was not a big carb eater). Last year, I was setting new PRs practically at every race!
So for me, I know a low carb high fat diet works. In fact, over the past few months I have been eating a high (for me) carb percentage due to a fruit obsession/addiction and I have seen a difference in my overall performance abilities.
So, I’ll be making a few tweaks to my diet starting today in an effort to give my body plenty of time to adjust to the changes before my half marathon.
With proper planning, I’ll work to make a diet that is 40% Fat : 30% Protein : 30% Carbs
Let’s take a look at a few of the main sources of fat in my life.
It’s important, in fact crucial, to remember that a diet high in fat doesn’t mean a diet high in butter, saturated fats and crap.
High quality is key! Any time you’re aiming for improved performance.
- Salmon (I order mine from SizzleFish)
- Avocado (favorite avocado salad pictured above)
- Coconut Oil
- Nuts
- Eggs
- Flaxseed