Endurance athletes are a special breed. Putting oneself in long-lasting discomfort for no other purpose than to travel some distance faster than you ever have before takes a bit of a masochistic streak. The level of discomfort endurance athletes routinely experience should be more than enough reason to know and practice the following unique recommendations for endurance athletes. Anything that can allow greater performance with less suffering is worth a shot, and these recommendations can revolutionize someone’s performance if they’ve been missing the mark.
1. Intraworkout carbohydrates needed per hour for maximal performance increases the longer the training session or competition is.
You’re probably under-consuming during your longest training sessions. 60-90g carbs per hour is needed to maximize performance during exercise sessions lasting longer than 2.5 hours. Body weight doesn’t matter here. If you’re a 60 kg woman or a 95 kg man, those needs and abilities to digest carbs remain similar across body sizes. There is some individual variability, but it is virtually guaranteed that you’re not maximizing your performance if you’re falling short of 60g per hour for efforts near 3 hours and longer. There are a host of reasons to target more than that per hour, including unplanned elongation of the training session or race, forgetting to consume. Some athletes can actually consume closer to 110-120g carbs per hour if composition of sugars is appropriate, which brings us to number two.
2. Intra workout carb composition matters for endurance sessions 3 hours and up.
When you’re going to consume anything over 60g of carbs per hour it is imperative that a portion of the carbs come from fructose. Of course, glucose (aka dextrose) is the widely preferred rapidly digestible sugar for the mainstay of any time you target 60g/hour, but your glucose transporter proteins in your small intestines get easily saturated above 60g/hour of dextrose consumption and increasing dextrose consumption further only leads to gastrointestinal distress. Fructose has its own gateway protein through the walls of the small intestine and so can be added as a way to get more total carbs digested. When targeting 90g/hr, roughly 2/3 glucose and 1/3 fructose is considered optimal.
3. Fat and fiber should be avoided during training. I’m looking at you, endurance athletes!
I don’t know that you’d catch too many weightlifters consuming an intra-workout snack with 7+ grams of fat in it between sets of squats. Okay, caught red-handed… I’ve been known to eat a couple pop tarts during weight training, in a pinch. It’s certainly not optimal, and it’s actually much less optimal for endurance athletes. Digestion is far more compromised in continuous activity than in intermittent activity, and the presence of fats or fiber in the intra-workout nutrition only furthers the digestion slow-down. Ironically, there are a bounty of products marketed to endurance athletes as great sources of energy that contain far too much fat and fiber for optimal carbohydrate delivery during endurance training. Anything with nuts, whole fruit, or fat added for taste as is often done in energy waffles, cookies and bars should be avoided entirely during training.
4. If using gels, chews, bars, etc to meet intra-workout carb needs, hydration sometimes matters heaps, and sometimes much less.
“Hydration, hydration, hydration!” Often cited as a highly important factor for endurance performance by inexperienced and unscientific coaches. It turns out, as long as you’re normally hydrated when you start any training session lasting under 75 minutes it’s very unlikely that a you might lose enough fluid through breathing and sweat losses to incur a measurable performance decrement due to the hydration changes themselves. Temperature regulation and delivery of carbs can probably be best accomplished with fluid consumption, so those things might be first affected by lack of drinking, but your actual hydration status isn’t likely to affect performance negatively unless you’ve exceeded 2% of body weight losses due to fluid loss. This is super important for folks competing in races, or completing training sessions, lasing more than ~2 hours because at that point it is quite possible to lose >2% of body weight if no fluids are being consumed. If for ease you decide to use gels, chews or bars to meet your hourly carb needs for longer periods of activity, it’s essential to also consume 500-1000 mL water per hour or risk sufficient dehydration to ruin performance, or worse.
5. In most cases it’s optimal to match caloric expenditure during training with equivalent calories from carbs throughout the day.
One of the most common questions among endurance athletes is “How much do I need to be eating to fuel for and recover from my training and competition?” The good news is, it’s simple in most cases. First, figure out how many calories you’re burning during your training using body weight and online calculators or something like a power meter on a bike or ergometer of some kind. Then, consume sufficient carbs over the course of the day to add up to the calories burned during activity. If you’re losing weight unintentionally while still consuming .6-1g/lb protein and ~.3g/lb of fat, then you can allocate more calories to carbs for the remainder of your balance, until desired weight loss rate or maintenance is achieved
6. Caffeine: You’re under-dosing.
Endurance athletes are notorious for underestimating carbohydrate and electrolyte consumption needs, and caffeine appears to follow a similar trend. Caffeine isn’t essential, but, if you’d like to get the most performance enhancement possible while using it, then it’s probably a good call to stop messing with 25mg here and 40mg there towards the end of the race. I can’t tell you how many times I’ve heard “I was feeling really rough towards the end of the race but then I took a gel and it really powered me through because of that little caffeine kick.” The “kick” that resurrects you when you’re in the pits of despair (aka hypoglycemia compounding fatigue from racing/training) is probably much more tied to the sugar in that gel, than the meager amount of caffeine. If you want the full benefits of increased focus and alertness, mood and motivation enhancement, and free fatty acid liberation, all from caffeine supplementation then get closer to 3-6mg/kg body weight about 30-45 minutes prior to racing or training. Caffeine blood concentration peaks roughly an hour after consumption and may be metabolized faster during exercise, so if you’d like to maintain the caffeine concentration in your body for the same benefit for the whole race then it’s probably wise to consume another .5-1 mg/kg body weight per hour for the remainder of your event.
7. Cutting carbs during a fat loss phase for an endurance athlete should be a last resort.
Retaining high muscle glycogen content may be important to encourage hypertrophy in folks who seek muscle gain and strength improvement, but it is absolutely paramount in endurance athletes if training quality is at all important. Thus, fats are the first to go, when calories are necessarily reduced during a fat loss phase, and then protein goes next, often down to .6g/lb to spare the carbs from being cut out of the diet to reduce calories.
Want more info? Check out the RP Diet Book 2.0 chapter on competition preparation, and the upcoming RP book on endurance nutrition.
RP offers running training plans from 5k to a marathon and will be releasing the newest addition to the line-up: RP Half Marathon, in January. To round out the RP Endurance stable of products, January will also see a resistance training program targeted specifically for enhancing endurance performance. Email firstname.lastname@example.org with any questions.