Built to last: Formulating for endurance

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Beware the bonk. If you’ve ever competed in an endurance event—or even just trained for one—you understand the wisdom behind those words. For bonking—or hitting the wall, gassing out or otherwise finding yourself energy-depleted mid-effort—is both the stuff of athletes’ nightmares and a very real physiological phenomenon.

And while helping people avoid it is arguably the raison d’etre for endurance nutrition, as more casual spectators discover their inner Olympians, they’re expanding the concept of “endurance” well beyond the bonk.

As Tom Stamsnijder, a former professional cyclist and group communications manager, team dsm-firmenich (Maastricht, The Netherlands), puts it, “Endurance nutrition may be essential for maintaining peak performance during intense activity, but demand for endurance-focused foods and beverages is not limited to athletes. Endurance nutrition today has mass appeal, and that means opportunity in this space is bountiful.”

Bonking Defined

And yet: Bonking still happens—even though it doesn’t have to.

It all starts with glucose—the fuel for working muscles. Glucose can get to those muscles via blood, but muscles (and the liver) also store glucose in the form of glycogen, with the average civilian storing around 600 grams¹, and trained athletes packing in as much 50% more.²

It’s when muscles burn through all the glycogen stored and the circulating glucose that bonking occurs. “You then start to feel physiological symptoms such as fatigue, nausea and leg cramps, which inevitably lead to ‘hitting a wall’ and having a total inability to continue,”explains Mariko Hill, global innovations manager, Gencor (Austin, TX).

“Beyond this,” she goes on, “it’s an extremely unpleasant feeling, as you don’t have control of your own body, with loss of coordination and physical weakness—almost a final message from the body telling you, ‘Stop!’”

Pure Energy

Alas, “Bonking is not a rare phenomenon, particularly in endurance sports,” concedes Martin Felkner, product manager/senior expert branded ingredients, Finzelberg (Andernach, Germany). “If athletes aren’t appropriately fueled, be it for lack of knowledge or fear of digestive issues, they’re very likely to run into depleted glycogen stores at some point in an event. So, finding the right energy balance is crucial for any athlete, particularly endurance- and long-distance athletes.”

Traditionally, endurance formulations balanced on a strategic blend of carbohydrate sources, like cyclic cluster dextrin, whose molecular structure encourages quick yet steady absorption for a more sustained energy release. Compare this to carbohydrates that spike blood-sugar levels and precipitate an energy crash.

Similarly, formulators would often weigh glucose against fructose. On one hand, muscles access glucose more quickly than they do fructose and glucose more effectively rebuilds muscle glycogen following exercise, but on the other, the body’s ceiling for absorbing glucose tops out at around 60 grams per hour. This makes glucose the less-optimal choice for activities that last longer than about 150 minutes.

Holistic Help

In any event, as the ranks of endurance enthusiasts broaden to include folks who just want something to sip during a power walk, formulating solely around energy misses the mark.

Indeed, says Hill, “Endurance formulations now encompass several aspects of health, including fatigue delay, accelerated recovery, mental performance, pain reduction, injury and inflammation management, sleep optimization and muscle power improvement—all of which play critical roles in promoting improved endurance.”

Felkner agrees; in fact, he sees the entire sports- and active-nutrition spaces as having “evolved from a more physical to a holistic category.”

“Our bodies and minds are intertwined, and the more we learn about, for example, the gut-brain, gut-muscle, gut-lung and other axes, the better we understand physical and mental health as two sides of the same coin,” Felkner explains.

No wonder, then, that consumers want what Hill calls “an all-in-one type of finished product that combines unique ingredients across multiple structure/function categories.”

Botanically Boosted

Among those unique ingredients are botanicals. And as Felkner observes, “It’s interesting to see an increasing number of [botanicals] enrich the category.”

For example, he lauds adaptogens like rhodiola and ginseng for modulating stress and energy, while prickly pear (Opuntia ficus-indica), he claims, can both replenish depleted muscle glycogen and support healthy blood glucose levels. And Greek Mountain Tea (Sideritis species), he says, “fuels oxygenated cerebral blood flow for improved concentration.”

Hill notes that while a paucity of clinical trials involving female subjects has hamstrung evidence-based developments in women’s sports nutrition, she claims that Gencor’s Libifem—a fenugreek seed extract standardized to 50% fenuside actives—is the first botanical studied in a female-only athlete population for improved sports performance.

Namely, a recent double-blind, randomized, placebo-controlled clinical trial investigated the extract’s effects on exercise performance and body composition in females aged 25 to 45. The study found significant, dose-dependent changes in body composition, endurance, muscle strength and recovery among subjects taking the supplement.³

“This gold-standard study provides a better understanding of how functional ingredients can benefit female physiology safely and effectively,” Hill says. “Now, brands can develop supplements tailored to women’s specific needs while moving away from the traditional ‘one ingredient fits all’ or ‘shrink it and pink it’ approach of feminizing male-centric products.”

Rest and Recovery

Holistic endurance formulations also help users address recovery which, Stamsnijder says, “forms a major part of training schedules, as athletes and fitness enthusiasts recognize that what they consume after their workouts is as important as what they consume during.”

And for years, protein—read: complete protein rich in essential amino acids and especially branched-chain amino acids like leucine—has been the macronutrient most celebrated for promoting recovery. Yet while “complete” once implied “animal-based,” Stamsnijder says that “revolutionary new solutions are emerging...making plant-based proteins viable options, as well.”

By sourcing its CanolaPRO protein from canola press cake, for example, dsm-firmenich turned a byproduct of canola-oil production into a complete plant-based protein that doesn’t just promote recovery and muscle growth, Stamsnijder claims, but “blends effortlessly” into popular endurance-nutrition applications like ready-to-mix shakes and beverages, “significantly enhancing their protein content without altering texture or taste.”

The Second Bonk

Protein also thwarts what Angie Rimel, marketing communications manager, North America, Gelita (Eberbach, Germany), calls the second bonk—that is, the one related to lactate threshold.

“Lactate is the substance that appears in the blood as a result of anaerobic metabolism when oxygen delivery to tissues is insufficient to support normal metabolic demands,” she explains. The lactate threshold, it follows, is the point when lactate begins piling up in muscles because its production outpaces their ability to clear it.

The higher that threshold, Rimel declares, “the faster the athlete can go for an extended time—usually more than thirty minutes.”

But athletes toe a fine line because tipping above their lactate thresholds both compromises muscle efficiency and ushers in rapid fatigue—hence that second bonk—which is why Rimel says that what’s important isn’t so much the lactate threshold itself, but how fast and for how long an athlete can perform at it.

“Traditional products on the market address the energy supply,” she argues, “but both bonks matter to endurance athletes.” And to address the lactate one, she points formulators to Gelita’s PeptENDURE protein-collagen.

A double-blind, placebo-controlled randomized trial in which subjects participated in 12 weeks of a training regimen found that, compared to placebo, those taking 15 grams of collagen peptides experienced significant improvements in running performance in a one-hour time trial as well as velocity at both the lactate threshold and individual aenorobic threshold, as measured by a treadmill erogmeter.⁴

“By promoting adaptive changes in the mitochondria when taken daily for at least three months, PeptENDURE can increase endurance levels and enable athletes to run longer and faster,” Rimel concludes. “This makes it an appealing daily training partner for those participating in endurance sports, from long-distance running and triathlons to team sports and high-intensity gym work.”

Cellular Turbines

“Training” the mitochondria—those fabled “energy factories of the cell”—is a theme in endurance nutrition, and not without reason: these organelles are key to cardiorespiratory health. And as Hill points out, “Cardiorespiratory fitness is a crucial factor in athletic performance, particularly in endurance events.”

Results of a recent study showed that Gencor’s ActivAMP, a Gynostemma pentaphyllum extract standardized to the saponin actives Gypenoside L and 20(S)-Ginsenoside Rg3, improved mitochondrial respiration as well as performance in a 20-kilometer time trial by as much as 113 seconds, or roughly 4%.⁵

“To put that into perspective,” Hill notes, “Nike’s Alphafly running shoe sparked a massive controversy before the Tokyo Olympics because of the supposed advantage it gave runners. Peer-reviewed studies claimed that, thanks to a trio of carbon plates and cutting-edge midsole—the cushioning above the tread—the shoe served up a 4% increase in running efficiency and an estimated 3.4% in speed.”

So super were these “supershoes” that World Athletics banned them from elite competition in early 2020, all but forcing Nike to develop the Vaporfly—which is still super, but not quite as much. The take-home as Hill sees it: “Undeniably, a natural botanical that can improve performance to similar levels is a game-changer.”

Striking Synergies

Shawn Baier MS, MBA, president of business development, TSI Group (Missoula, MT), notes that myHMB, TSI’s branded calcium β-hydroxy β-methylbutyrate, has a record of improving lactate threshold, respiratory compensation point, VO2max and other key endurance indicators. “Furthermore,” he adds, “there’re proven synergistic benefits in building lean muscle mass and strength when consuming myHMB plus creatine during activity.”

Creatine—which, along with caffeine, is one of the most scientifically supported sports-nutrition supplement out there—also pairs nicely with TSI’s Peak ATP, a patented form of adenosine 5’-triphosphate disodium that is structurally identical to the ATP the body produces. Both compounds participate in the ATP-CP energy system that powers explosive efforts during high-intensity work, “giving formulators significant opportunity to create simple yet effective products for consumers,” says Baier.

Chase Hagerman, president, Golden Key Ingredients (Georgetown, TX), points to a foundational study in the Journal of the International Society of Sports Nutrition⁶ showing that reductions in free choline during intense exercise can hamper acetylcholine release and, by extension, endurance and performance.

“Simply put,” Hagerman explains, “alpha-GPC is a choline compound that raises levels of the neurotransmitter acetylcholine in the body, and from a commercialization standpoint, our GPCgold alpha-GPC is exciting for endurance formulas because it’s flavorless and soluble, making it ideal for beverage, gel, gummy, bar and other gustatory delivery formats that’re commonly seen in this segment.”

Reaching the Finish Line

Formulating effectively with these ingredients requires understanding which flavor of endurance a brand’s particular audience seeks. And Hagerman advises brands to remember that a formulation for the casual competitor won’t necessarily give a serious podium contender an edge.

“This distinction between aspirational and actual audiences should be a key consideration,” he emphasizes. “The strategic choice for brands is whether to remain true to their niche demographic or to pursue broader market appeal—because often there’s a direct correlation between cost and efficacy, and, sadly, the best-performing products are not mass sellers.”

According to Stamsnijder, product platform deserves deliberation as well, to help athletes time nutrient intake for optimal delivery and absorption. “For example, some might prefer the convenience and rapid absorption of gels during a marathon,” he says, “while others might opt for the more sustained energy release provided by bars during a long cycling tour. The key is to offer a range and cater to diverse preferences, ensuring that athletes have a variety of options to stay energized and hydrated throughout their activities.”

Whatever the formulation, Stamsnijder concludes, “Helping athletes attain peak performance and wellbeing requires a holistic view of nutrition. It’s about supporting the body in maintaining long-term health and sustaining performance, reflecting a more modern and inclusive understanding of what true endurance entails.”

References

1. Murray, B.; Rosenbloom, C. “Fundamentals of glycogen metabolism for coaches and athletes. 2018. Nutrition Reviews, 76 (4), 243-259. DOI: 10.1093/nutrit/nuy001 
2. Kerksick, C.M.; Arent, S.; Schoenfeld, B.J.; Stout, J.R.; Campbell, B.; Wilborn, C.D.; Taylor, L.; Kalman, D.; et al. “International society of sports nutrition position stand: nutrient timing.” Journal of the International Society of Sports Nutrition. 2017, 14 (33). 
3. Rao, A.; Clayton, P.; Briskey, D. “Libifem (Trigonella foenum-graecum) in conjunction with exercise on muscle strength, power, endurance, and body composition in females aged between 25 and 45 years.” Frontiers in Sports and Active Living. 2023, 5. DOI: 10.3389/fspor.2023.1207013 
4. Jerger, S.; Jendricke, P.; Centner, C.; Bischof, K.; Kohl, B.; Keller, S.; Gollhofer, A.; König, D.. Effects of Specific Bioactive Collagen Peptides in Combination with Concurrent Training on Running Performance and Indicators of Endurance Capacity in Men: A Randomized Controlled Trial. Sports Medicine-Open, 2023, 9 (1). DOI: 10.1186/s40798-023-00654-9. 
5. Ahnm Y.; Lee, H.S.; Lee, S.H.; Joa, K.L.; Lim, C.Y.; Ahn, Y.J.; Suh, H.J.; Park, S.S.; Hong, K.B. Effects of gypenoside L-containing Gynostemma pentaphyllum extract on fatigue and physical performance: A double-blind, placebo-controlled, randomized trial. Phytotherapy Research. 2023, 37 (7), 3069-3082.DOI: 10.1002/ptr.7801. 
6. Jäger, R.; Purpura, M.; Kingsley, M. Phospholipids and sports performance. Journal of the International Society of Sports Nutrition. 2007, 4 . DOI: 10.1186/1550-2783-4-5.

Kimberly J. Decker writes for the food and nutrition industries from her base in the San Francisco area where she enjoys eating food as much as she does writing about it.