Nutrition
What a topic.
Right up front, I am not a nutritionist, or a Dietician. I am a life-long athlete, 16-year full-time professional endurance sports coach and have yearly access to USOPC staff that include dietitians and physiologists. So I've learned a lot - mostly through success and failures with athletes - but also through discussions with my peers, in educational classes, sessions between Dietitians and their athletes and constant reading.
So, with all that, the number one answer to most nutritional questions is, "It depends". Not what most athletes want to hear, right? But it's true. It's an exceptionally complex, individualized and constantly evolving science for the endurance athlete.
My "kick-off" to any discussion is the following:
There are no absolutes in training, and there are no secrets in training. Additionally, everyone is different. What I talk about below is “in general”, “rule of thumb" or “bell curve”. Obviously there are outliers, and you may be one of them. What I write here is current (as I write it) nutrition principles as they apply to endurance sports athletes during training and racing.
Carbohydrates (CHO)
Arguably the most important change to all endurance sports within the last 70 years is the understanding of how to correctly fuel athletes during training and racing. In the past, shooting for “metabolic efficiency” or promoting “fat oxidation" was often a main goal in training achieved by under-fueling. That would also promote weight loss.
What we’ve found now is that this was completely wrong. Under-fueling not only inhibits quality training, but also negatively affects muscle recovery following exercise. The human body is burning way more calories than we thought.
In the past, we knew that our intestine could only take in ~60 grams (240 calories) of carbohydrates (CHO) an hour before they “closed up”. If we ingested more within that time, it caused all sorts of variable G.I. issues. Now we know that if we target the correct combination AND ratio of carbohydrates, there is NO limit on the number of grams of carbohydrates per hour that the body can absorb. Currently, professional Ultra Runners, Triathletes and Cyclists are experimenting with upwards of 160+ grams (640 calories) an hour of CHO for upwards of 14+ hours of racing.
The following is a brief overview of of the concept, taken from www.Never2.com:
Glucose uses a “transporter” (a protein called SGLT1) to “move” it through the cell membranes. But it can only move about 1 gram per minute, or 60 grams per hour - hence the limit of ~60grams per hour. Anything not absorbed accumulates in the intestine.
But, if we add another carbohydrate with a different transporter, we could actually “open up the doors” to our cells and absorb infinite amounts of carbohydrates. Fructose is that carbohydrate (transported by GLUT5). Because glucose and fructose use different transporters, they are often referred to as multiple transportable carbohydrates or MTC.
The following combinations of carbohydrates proved most effective:
maltodextrin:fructose
glucose:fructose
glucose:sucrose:fructose
In all cases, the glucose transporter needs to be saturated and this will not happen if less than about 60 grams per hour is ingested. The additional second carbohydrate (fructose) will have to be ingested at sufficient rates to add to the carbohydrate delivery (30 grams per hour or more).
If these amounts are ingested it gives you a ratio of 2:1 glucose:fructose and an intake of 90 grams per hour. But this can vary and nothing is exact. This ratio is most effective when used for training greater than 2.5 hours.
Below is a chart I made and use with athletes I work for:
If you're training over 5 hours a week, I believe you should fuel yourself every time you train, whether that's for 20 minutes or for 4 hours. So, reading the above chart, to keep it simple, I recommend you fuel yourself up to 30 grams (120 calories) of CHO for any training up to an hour. That could be one gel, one scoop of your favorite caloried drink or any combination.
From 1-2 hours, shoot for 30-60 grams PER hour. That could be one gel each hour or 1 gel every 30 minutes, for example.
2-3 hours we want a MINIMUM of 60 grams per hour. That's the minimum and what I recommend all athletes try to get to, regardless of gender and weight (*But remember the "bell curve" I reference above*). For this period of training time, 60-90 grams per hours works great.
And, obviously, anything over 3 hours we should be trying to get closer to 90 than 60. Many athletes will easily be able to take 100-120 grams/hour. But if you're not one of them, no worries! Just get close to or at 90 grams / hour.
Remember that if you do a strength session, then go to straight into a bike ride, you'll need to add those two sessions together and treat them as a longer session when determining your nutrition requirements.
Another note: I recommend using products that are third party tested by companies such as NSF Certified for Sport. Why? Well we know that they are batch tested constantly for WADA prohibited substances, but really when a product is NSF certified, its ingredients are verified. Another certified tester is Informed Choice (or Informed Sport) certified. Either is a great piece of mind that you’re getting exactly what is advertised.
Supplements
Before taking any supplements, you should check with your doctor or dietician. In general, though, most endurance athletes will need some supplemental nutritional support due to the volume, frequency and intensity of training on a weekly basis. Endurance athletes should be aware of the demands on their body in training and racing and supplement appropriately to improve performance, recovery and overall heath.
I do not normally make it a habit to recommend anything other than increased protein (whole food or not) to athletes.
That said, I believe there is a small group of supplements that should be considered that can benefit most athletes in some amount and form. Again, each athlete should check with their doctor or dietician first.
Sodium
Sodium is the other essential ingredient we need to "track" within our CHO nutritional plan while we train. It is one of the 5 Electrolytes (Potassium, Magnesium, Calcium & Chloride are the others) that we need. Referencing Sodium, most people will need somewhere between 200 to 800 mg of sodium per hour during exercise, but, of course, there are many factors that determine how much each of us needs.
To really know, athletes would need to test their baseline sodium levels and then determine if they're a big sweater or not. Regardless, the main companies that understand the new CHO transporter types and ratios now simply also include sodium. So start to pay attention to this.
Caffeine
Caffeine is a natural stimulant that can improve endurance, promote alertness and increase reaction time. It can also reduce fatigue perception. A typical healthy range of mg of caffeine in the body is roughly 3-5mg per kilogram of weight.
So, If you weigh 170lbs, or 77.11 kilograms, then your healthy range would be 231mg - 386mg. Of course, you may be fine going over this “range”, or you may not. Going over could cause nervousness, G.I. issues, etc.
Caffeine peak benefit typically occurs 45-60 minutes after ingestion. In other words, you’ll see the max benefits of caffeine about an hour. This knowledge can then be used to strategize on when to take caffeine during longer training and racing scenarios.
How Long Does It Stay In Body? Here’s the kicker - it has a half-life of 5 hours! So if you down 3 cups of coffee, one right after another, and have ~300mg of caffeine in your body, you’ll still have 150mg in there 5 hours later! The moral of the story is to spread out your intake!
Protein
Most of us know that protein is essential for muscle growth and repair. And, if you look closely, there are many food products that contain protein besides meat. So we can get a good amount of protein just from eating well - without supplementing. However, as an active endurance athlete, you probably aren't getting enough.
It's generally recommended that athletes target .8-1.2 grams of protein per pound of body weight. However, higher performing athletes and those with big training days may need to take more. It's not exact, and really, like most supplements, consistency is key. How much at a time? 20-40 grams is the window that works best for most athletes.
When we take protein after workouts within an appropriate amount of time, we're targeting muscle recovery and helping to reduce soreness and promoting muscle synthesis. The most common delivery system is protein powder that is made into shakes. I recommend taking protein within that first hour after the training session.
Do we need carbohydrates along with that post training protein supplement? It may speed up delivery to the body, but you don't need that much. A 2:1 or 3:1 carbohydrate to protein ratio is plenty (if you're fueling correctly with CHO during the session).
Creatine
There is now enough research done to recommend creatine supplementation to endurance athletes on a daily basis. While it's a naturally occurring compound in the body that enhances energy production during high-intensity exercise, it also has been found to aid in recovery post exercise as well as support cognitive function.
In general, it's recommended that athletes supplement 5 grams per day. While it's not important when you take it daily, it is important to take it consistently every day. With added creatine, there may be a very small weight gain due to water retention within the muscles, so ensure that you stay hydrated.
Some athletes have found an initial "bloating" feeling during the first few weeks of supplementation, in which case reducing the amount per day should cause a positive response. Over time, though, most athletes adjust just fine.
Footnote:
A great reference of many supplements that can be beneficial to endurance athletes can be found in an article written by Emma-Kate Lidbury for the Nutritional Supplement company, Momentous. While I did reference her article for some of the above info, I also changed some info based on my learning and experience. I highly recommend Momentous if you are interested in using supplements as a place to get them from.