Learning Activity
1. The physiological response of carbohydrate loading in sports.
“The availability of energy during exercise modulates the physiological response to
training states Mata et al.”1 Endurance athletes obtain energy requirements by increasing their
carbohydrate intake. Carbohydrate loading produces higher amounts of glycogen storage which
is primarily in the liver and muscles. When needed, an athlete’s body transforms the stored
glycogen to glucose for fuel throughout the event. In addition to increasing carbohydrate
consumption prior to the event, an athlete can consume carbohydrates during the event. For
example, marathon competitors often consume carbohydrate gels throughout the run to avoid
“hitting the wall”. A study conducted by Kozlowski et al states, “endurance athletes have long
used carbohydrate supplementation during prolonged exercise (most recently with energy gels)
which elevates blood glucose levels and enhances performance.”2
2. The process of carbohydrate loading.
Since this athlete wants to run marathons, the process of carbohydrate loading should be
personalized using factors such as body weight, when the event starts, and duration of the event.
For the first half of the week prior to a marathon, he should focus on expending and consuming
the least amount of carbohydrates.3 During the second half, he begins “the repletion stage;
supplying large amounts of carbohydrate to glycogen-starved muscles. In response, the body
“supercompensates,” and near maximum glycogen storage is achieved.”3
3. The advantages and disadvantages of various carbohydrate
loading techniques.
2
Learning Activity
Scientific evidence suggests that carbohydrate loading is advantageous to improving
performance. On the contrary, there are also disadvantages. One article addresses the positive
and potential negative effects. Redman states, “research shows that carb loading may improve
athletic performance and reduce fatigue by 2-3% for activities longer than 90 minutes, which is a
considerable amount in relation to competitive sports.”4 However, improper or lack of
knowledge could lead to adverse outcomes. For instance, the author notes “diabetes, bloating
and/or digestive discomfort, and weight gain” as possible disadvantages.4
4. The timing, amount, and listing of appropriate food sources for
carbohydrate loading.
The timing, amount, and food sources are key components of carbohydrate loading. As
well as the previously discussed process, a high carbohydrate meal 1 to 4 hours before starting
his event will be beneficial.3 The amount of carbohydrates are specific to his needs. As an
example, assuming this athletes weighs 65 kg, he should consume 195 to 780 g/kg of
carbohydrates to meet the daily recommendation “(3-12 g/kg, 7.6 g/kg for male endurance
athletes).”3 The best food sources are those with natural carbohydrates. As artificial sources
primarily consist of additives. Food products such as plain or whole grain bagels, oats, fruits, and
vegetables are appropriate choices to fulfill his requirements.3
5. Any additional information needed to explain the why, how, when,
and what of carbohydrate loading.
Athletes participating in endurance sports require a constant flow of energy.
Carbohydrate loading is not only important prior to and during an event, but the process is also
useful for recovery. Garone says, “when paired with protein, eating carbohydrates post workout
3
Learning Activity
helps prevent post workout fatigue, helps control blood sugar, promotes muscle recovery, and
helps reduce cortisol.”5 Another aspect of carbohydrate loading is adequate hydration. “The
dietary goals of the athlete prior to exercise include avoiding hunger, delaying fatigue,
minimizing gastrointestinal distress, and preventing hypohydration (below a normal state of
hydration).”3 This athlete is young and in good health. With proper guidance, an individualized
nutrition plan will set the foundation for ideal endurance and performance.
4
1.Mata F, Valenzuela PL, Gimenez J, et al. Carbohydrate availability and physical performance:
physiological overview and practical recommendations. Nutrients. 2019 May 16;11(5):1084.
doi:10.3390/nu11051084. PMID: 31100798; PMC6566225. Accessed September 10, 2023.
https://www.ncbi.nlm.nih.gov/.
2.Kozlowski KF, Ferrentino-DePriest A, Cerny F. Effects of energy gel ingestion on blood glucose,
lactate, and performance measures during prolonged cycling. J Strength Cond Res. 2021 November
1;35(11):3111-3119. doi: 10.1519/JSC.0000000000003297. PMID: 31977833. Accessed
September 10, 2023. https://pubmed.ncbi.nlm.nih.gov/.
3.Dunford M, Doyle JA, Killian L. Nutrition for sport and exercise. 5th Edition. Boston, MA:
Cengage; 2022.
4.Redman J. Carbohydrate loading | benefits, tips, and side effects. October 28, 2021. Accessed
September 10, 2023. https://www.scienceinsport.com/.
5.Garone S. Should i eat carbs after my workout? October 25, 2022. Accessed September 10, 2023.
https://www.verywellfit.com/carbs-after-a-workout-6748707.
Powered by TCPDF (www.tcpdf.org)
