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XSurge helps with exercise fatigue

Fighting Fatigue

We all know what exhaustion feels like. Feeling burnt out by work, struggling to find the motivation to exercise and feelings of general tiredness plague many of us.

What causes fatigue?

It's common for Americans to experience fatigue - even without health conditions associated with chronic fatigue.1 It's also common to experience fatigue during intense exercise, resulting in decreased performance.2,3 Both general fatigue (feelings of tiredness) and fatigue experienced during exercise have mechanisms that are influenced by multiple factors in the central nervous system, including adenosine accumulation in the brain.4 Adenosine is a neurotransmitter that interacts with receptors in the brain to induce drowsiness and sleepiness. Caffeine works by blocking the adenosine receptors and stimulating the central nervous system.5,6 

A 2016 supplement use survey conducted by the Council for Responsible Nutrition (CRN) suggests that of the 170 million supplement users in the United States, the second most prevalent reason for taking supplements is to increase energy.7 Many products with claims of increased energy contain some type of central nervous system stimulant, like caffeine. Market research continues to suggest that the demand for more energy will continue to grow, especially among millennials who want to achieve maximum levels of mental and physical performance every day.8 

When it Comes to Caffeine, Clean-label Matters

Of the consumers that are looking for a boost in energy, 1 in 4 are committed to finding safe products with all-natural ingredients.8 Caffeine, the standard active ingredient in energy-boosting products, can come from both natural and synthetic sources. Caffeine naturally occurs in over 60 different plants and is most commonly consumed in the diet through coffee and tea.5 Natural and synthetic caffeine are chemically identical, but natural caffeine - especially that sourced from tea plants - can provide a range of health benefits like improved fat oxidation, improved antioxidant status and benefits during exercise.9-15 

A Cup o' Tea Won't Cut It

So why not just brew a cup of tea before working out? Although brewed tea is a natural solution for consuming energy-boosting caffeine, there are limitations. The caffeine content in brewed tea can vary based on plant type, growing conditions and brewing conditions. Studies have shown ranges of 40-120 mg caffeine per 8 oz serving of brewed tea.5 The low end of this range falls below the dose at which increased energy, focus and athletic performance benefits of caffeine have been supported by research, so your cup of tea may not offer the same pick-me-up as more concentrated caffeine sources.

Chemical Extracts Aren't the Only Answer

To alleviate the variability of caffeine content, energy-boosting product manufacturers commonly extract caffeine from natural sources and concentrate it at higher, more consistent levels. The downside to these extracts is that most require the use of chemical solvents that remove other beneficial active compounds. According to CRN research, consumers' number one reason for purchasing supplements is overall health and wellness benefits, so why strip your product of its natural health-benefitting compounds?

XSurge™: Water-extracted Caffeine

Kemin has gone to great lengths to find a proprietary ratio of green and black tea (Camelia sinesis) that provides optimal levels of caffeine for a natural energy boost. By using a water extraction process, our tea retains the catechins from green tea and the theaflavins from black tea to provide additional health benefits. In addition to the benefits of caffeine, results from clinical trials of XSurge have shown improved antioxidant status, muscle recovery and reduced inflammation after damaging exercise.

Add XSurge to Your Formulation

XSurge meets two popular consumer needs by providing an energy boost alongside antioxidant and exercise-recovery benefits. Click here to learn more about our safe and natural tea extract.


1.            Ricci JA, Chee E, Lorandeau AL, Berger J. Fatigue in the US workforce: prevalence and implications for lost productive work time. Journal of occupational and environmental medicine. 2007;49(1):1-10.

2.            Lambert E, Gibson ASC, Noakes T. Complex systems model of fatigue: integrative homoeostatic control of peripheral physiological systems during exercise in humans. British Journal of Sports Medicine. 2005;39(1):52-62.

3.            Davis JM, Bailey SP. Possible mechanisms of central nervous system fatigue during exercise. Medicine and science in sports and exercise. 1997;29(1):45-57.

4.            Pageaux B, Marcora SM, Rozand V, Lepers R. Mental fatigue induced by prolonged self-regulation does not exacerbate central fatigue during subsequent whole-body endurance exercise. Frontiers in human neuroscience. 2015;9.

5.            Heckman MA, Weil J, De Mejia EG. Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. Journal of Food Science. 2010;75(3):R77-R87.

6.            Davis JK, Green JM. Caffeine and anaerobic performance: Ergogenic value and mechanisms of action. Sports Medicine. 2009;39(10):813-832.

7.            Supplement Use Among Younger Adult Generations Contributes to Boost in Overall Usage in 2016 - More than 170 Million Americans take dietary supplements [press release]. Council for Responsible Nutrition Webpage: Council for Responsible Nutrition2016.

8.            Moloughney S. Energy Trends: The Market Charges On. Nutraceuticals World. Vol Online: Rodman Media; 2017.

9.            Hursel R, Viechtbauer W, Dulloo AG, et al. The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta‐analysis. Obesity reviews. 2011;12(7):e573-e581.

10.          Dulloo AG, Duret C, Rohrer D, et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. The American journal of clinical nutrition. 1999;70(6):1040-1045.

11.          Arent SM, Senso M, Golem DL, McKeever KH. The effects of theaflavin-enriched black tea extract on muscle soreness, oxidative stress, inflammation, and endocrine responses to acute anaerobic interval training: a randomized, double-blind, crossover study. Journal of the International Society of Sports Nutrition. 2010;7(1):1.

12.          Suzuki K, Takahashi M, Li CY, et al. The acute effects of green tea and carbohydrate coingestion on systemic inflammation and oxidative stress during sprint cycling. Applied Physiology, Nutrition and Metabolism. 2015;40(10):997-1003.

13.          Hursel R, Westerterp-Plantenga MS. Catechin-and caffeine-rich teas for control of body weight in humans. The American journal of clinical nutrition. 2013;98(6):1682S-1693S.

14.          Benzie IF, Szeto YT, Strain JJ, Tomlinson B. Consumption of green tea causes rapid increase in plasma antioxidant power in humans. Nutr Cancer. 1999;34(1):83-87.

15.          Panza VSP, Wazlawik E, Schütz GR, Comin L, Hecht KC, da Silva EL. Consumption of green tea favorably affects oxidative stress markers in weight-trained men. Nutrition. 2008;24(5):433-442.