Nutrition Fads: Many Tried, Few True

By Ian McMahan | June 26, 2018, 1:14 p.m. (ET)

We all wore fashion choices that seemed good at the time — velour tracksuits and acid wash jeans — but now we shudder when we looked back at old photos. Similar to regretful choices in fashion, nutrition has had its share of fads.

In fact, popular nutrition, not just that of endurance sport, is virtually defined by the waxing and waning of nutritional trends — high carb, no-carb, Pritikin, Banting and Paleo, etc. Like any individual looking for benefits, triathletes are drawn to the newest nutrition fads in hopes they will provide a quick boost in performance. However, many have been tried, but even fewer are true. 

Let’s take a look at some of the nutritional fads that have come and gone (or stuck around) in the sport of triathlon.

Fad: Ketogenic Diet

Mark Allen (six-time IRONMAN World Champion): “The biggest fad I am seeing now is people completely starving themselves of carbohydrates to reach a state of ketosis. It’s the complete opposite extreme of when I started in the sport in the 1980s, when athletes were trying to follow the Pritikin diet of high carbs and low fat. From what I can gather, there seems to be mounting evidence that when someone is in ketosis, their training quality drops as well as getting changes in blood chemistry and lipid profiles that are not healthy. On top of that, my guess is that over time a ketosis diet will not be something that people can sustain.”

What the science says: Because a high fat/low carb diet might enable the body to better use fat as fuel, some have attempted to use supplements to mimic that effect. Early reports suggested that ketones (or a state of ketosis), byproducts produced by the liver that the muscles and brain can use as fuel, could be used to improve performance. A 2016 study, performed by researchers at Oxford University, found that cycling time-trial performance was significantly improved when ketones were added to a carbohydrate drink. 

However, more recent research on ketones, including a study by a group of researchers at the Australian Institute of Sport, determined that ketones impaired time trial cycling performance in elite cyclists. The conclusion, and note of caution, stated, “This outcome appears to be linked to the general observation of gut discomfort and intolerance among the study participants, with symptoms ranging from mild to severe.”

Fad: Mustard Packets

Meredith Kessler (10-time IRONMAN and 20-time half-IRONMAN champion): “When you feel like you are on the brink of cramping, put some mustard on your tongue and it’s supposed to send a neurological message to the brain to stop cramping. This all could be a misnomer yet it works for me!”

What the science says: This practice might have reached peak popularity when football players began using pickle juice and mustard to prevent cramps. Though research has determined that high-sodium mustard and pickle juice doesn’t adequately replenish electrolytes, they can be effective in reducing exercise-induced muscle cramping. The researchers concluded, “This effect could not be explained by rapid restoration of body fluids or electrolytes. We suspect that the rapid inhibition of the electrically induced cramps reflects a reflex that originates in the (mouth) region and acts to inhibit the cramping muscle.”

Fad: Gels Plus Water Plus Salt Cocktail

Tim O’Donnell (2009 ITU Long Distance Triathlon World Champion, 2015 IRONMAN World Championship podium finisher): “I put my CLIF SHOT energy gel in a flask and mix with my sodium and water. It makes it a little easier to ingest while racing and allows you to consume at your own pace. Combining the sodium with the CLIF SHOTS means there is one less thing to worry about taking when you are out on the course.”

What the science says: Carb ingestion during exercise has been correlated with faster finishing times. Basically, it’s pretty well established that consuming carbs during exercise helps you perform better. But it’s also important to understand that higher levels of carbs can be associated with stomach upset and, putting it delicately, gastrointestinal problems. However, tolerance to carbs can be trained, and given the importance of fueling to performance, figuring out ways to get in enough carbs is a worthwhile endeavor. O’Donnell’s method, while personalized, is one such technique.

Fad: Beetroot Juice

Conrad Stoltz (Four-time XTERRA World Champion, three-time ITU Cross Triathlon World Champion): “I haven’t raced competitively the past two years, but the last ‘big thing’ of my pro career was the red blood cell-stimulating beetroot juice the month before the race. Luckily, I like beetroot. Just don’t pee in the pool.”

What the science says: A 2017 review article in the journal Sports Medicine concluded that so far, the benefits of beetroot — aka dietary nitrate supplementation — were restricted to the lab, and not the road. “Dietary NO3-supplementation is likely to elicit a positive outcome when testing endurance exercise capacity, whereas dietary NO3-supplementation is less likely to be effective for time-trial performance.”

Fad: Sodium Bicarbonate (Baking Soda)

Conrad Stoltz: “One thing that is old news but apparently works, is lactic acid buffering [using sodium bicarbonate]. Not for everybody, as it can be a bowel irritant.”

What the science says: Research on cyclists and triathletes suggests that sodium bicarbonate — aka baking soda — can limit the buildup of acid in the bloodstream and improve endurance performance. One such study found a 24-percent increase in cycling time to exhaustion after using the supplement. However, as Stoltz notes, the use of sodium bicarbonate can cause a laundry list of uncomfortable stomach and GI side effects. 

Fad: Flat Coke

Barb Lindquist (Olympian, USA Triathlon Hall of Fame inductee, USA Triathlon Collegiate Recruitment Program Coordinator): “I drank a Coke after races where the water quality seemed a bit dodgy. Coke cleans pennies to a shine and can clean blood from a crime scene, so why not do its magic on any ingested water I took in. Not once did I ever have a GI issue after a race, and I’ve swam in some pretty gross water. No science behind this one that I know of — maybe a wives’ tale or two.”

What the science says: Though Lindquist was referring to using Coke as a means to avoid “Traveler’s Revenge,” many endurance athletes use the soft drink at the end of a race for a little performance boost. A well-designed research study on the effects of Coca-Cola ingestion on endurance performance, again by researchers at the Australian Institute of Sport, found a performance benefit to the popular late race beverage. Interestingly, although the study found only a small increase in the blood levels of caffeine, there was a significant boost in performance likely due to both the “caffeine hit” and the sugar.

Fad:  Glucose (Sugar) Tablets

Barb Lindquist: “Four to six glucose tablets (for diabetics, over the counter) during the run to help my mind stay focused, especially in hot races. The brain only uses glucose.”

What the science says: The things are literally pure sugar, without electrolytes or other forms of sugar, like fructose. Though there isn’t any specific performance research on the glucose tablets for diabetics found in pharmacies, there is abundant research on glucose and endurance performance. In short, glucose (sugar) improves endurance performance, especially in long events like triathlons. One potential drawback with the glucose tablets is that they only provide a small amount of sugar (~4 grams), requiring 10 or more to equal the sugar in one gel or energy drink.

The Bottom Line

Of course, maintains Allen, a common sense approach to nutrition — balanced diet, eliminating refined sugar, eating good sources of high quality fats, getting enough quality protein and avoiding excessive amounts of grains — is kind of boring. But, focusing on the foundation of the pyramid, rather than just the fad supplements at the tip, might offer the best chance for improved performance. Finally, like training, a successful nutrition strategy varies depending on the athlete. What works for your training buddy may not work for you, so always test strategies in training before implementing for racing.