- Annie Bothma, 11 September 2022
Are you maximizing your nutrition leading-up and during your next key workout, long session or upcoming race, competition or endurance adventure?
Set yourself up for success by using your nutrition to get the most out of your training to lead the benefits when it matters most. Learning how to fueling right and enough can help you adapt properly, recover faster, and perform better!
Use the following strategies before and during your training and ultimately race to get the most out of the hard work you are doing in training.
TRAIN YOUR GUT JUST LIKE YOU TRAIN YOUR MUSCLES
START EARLY
Just like you won't start training for a marathon the week before the race, you shouldn't just start thinking about nutrition the week leading up to the big day. Neither would you wear a pair of brand new shoes on race day...So why would you try out a new gels, drink or other food the days prior to on race day.
Just like you train your muscles to tolerate more training, you can train your gut to tolerate food and fluids while you exercise. By gradually increasing the amount of fluids and food you ingest pre- and during exercise you can also increase the amount you are able to consume. This is a strategic approach that may help increase the gut’s capacity to absorb carbohydrates during exercise. This may reduce the residual volume in the intestine and reduce the risk of GI discomfort or problems during exercise.
PROTECT YOUR GUT
Frequent and consistent consumption of carbohydrate during exercise is a protective strategy against GI disturbance, since the presence in chyme, increased intestinal carbohydrate transport activity and carbohydrate post-absorption stimulate nitric-oxide induced vasodilation, the most potent stimulator for increasing postprandial microvascular blood flow in intestinal villi. Carbohydrate intake during exercise maintains splanchnic perfusion (attenuates exercise-induced hypo-perfusion) and ameliorates intestinal permeability in response to exercise stress and NSAID administration. It would be beneficial to identify individual carbohydrate intake tolerance levels in terms of the quantity and quality during exercise that requires an exogenous fuel supply. It is best to consume carbohydrates evenly and more frequently throughout exercise. (Casto, 2017)
AVOID GETTING DEHYDRATED
Dehydration over 2% of body-weight can impair performance, but avoiding dehydration is also very important for the gut. Dehydration may exacerbate gastrointestinal (GI) disturbances, due to the decreased blood flow to the gut. Carbohydrates like gels also need to be consumed with adequate fluids to ensure sufficient gastric emptying. On the flip side, over-hydration is also a risk during exercise, considering exercise-associated hyponatremia has also been linked to gastrointestinal symptoms (particularly nausea and regurgitation). It therefore appears that starting exercise well hydrated and minimizing fluid and electrolyte loss as much as possible throughout the duration of the session may help reduce GI disturbance. (Casto, 2017) Consuming fluid during training will also teach your gut to be comfortable handle carrying more fluids. Plus it will help you refine how much you need to consume on race day.
MAINTAIN STABLE BLOOD GLUCOSE
Carbohydrate ingestion during exercise over 90-minutes can also delay fatigue development by slowing the rate of liver glycogen depletion and helping to maintain the blood glucose concentration. Central fatigue is indicated by an impaired ability to sustain maximal muscle activation during sustained contractions can also be a major factor during prolonged exercise and can be accelerated if prolonged exercise is performed in a carbohydrate depleted state. Without adequate carbohydrate intake before or/and during training athletes may run the risk of developing hypoglycemia (low blood sugar). (Jeukendrup, 2019).
IMPROVE TRAINING ADAPTATIONS AND AVOID INJURY
Training with sufficient carbohydrates during exercise and ensuring your carbohydrate intake is high in the weeks leading up to an important race will also help improve your training adaptations, lead to better recovery, reduce the likelihood of injury and avoid low-energy availability (LEA).
USE DIFFERENT CARBOHYDRATES SOURCES
Greater carbohydrate intake has been associated with improved performance. During prolonged exercise, the performance benefits of carbohydrate ingestion may be achieved by maintaining plasma glucose concentration and high rates of carbohydrate oxidation.If you are aiming to consume more than 60g of carbohydrates per hour it is best to use different types of carbohydrates, since limitations to exogenous carbohydrate oxidation appear to be in the absorptive process most likely because of a saturation of carbohydrate transporters. By using a combination of carbohydrates that use different intestinal transporters for absorption (multiple transportable carbohydrates), carbohydrate delivery and oxidation can be increased. Studies demonstrated up to 65% higher exogenous carbohydrate oxidation rates of multiple transportable carbohydrates, such as glucose:fructose combinations during exercise compared with a single carbohydrate source such as glucose only.
Recommended carbohydrate (CHO) intakes per hour to optimize performance:
Exercise lasting less than 1-hour: Mouth rinse or nothing.
Exercise lasting 1-2 hours: 30 - 60g of CHO/h
Exercise lasting greater than 2-2.5 hours: 60 - 90g of CHO/h
PRACTICE MAKES PERFECT
Athlete's should be experimenting in training with pre-race and race-day nutrition multiple times during training before the big day arrives. Figuring out what works best will reduce the likelihood of GI issues ruining the race. Test out many different brands to find out which ones you like and would allow you feel and perform at your best. These should be easy to digest carbohydrate-rich options with minimal fat, fibre and protein as these slow down digestion. Sports foods such as gels, energy chews, sports bars and sports drinks are suitable choices and easy to carry on the run course. Consuming a standard 6% carbohydrate sports drink at aid stations located throughout an event will help to meet carbohydrate and fluid needs simultaneously.
SUMMARY:
Train your gut during training to take on fluids and fluid.
Start practicing frequently and well in advance of race day during training.
Frequent and consistent consumption of carbohydrate during exercise is a protective strategy against GI disturbance, since the presence in chyme
Avoid dehydration or over-dehydration by starting exercise well hydrated and consuming sufficient fluids throughout. Consume fluids with solid carbohydrates sources like gels and bars.
Maintain stable blood glucose and avoid hypoglycemia.
Consuming sufficient carbohydrates during training can help improve training adaptations, lead to better recovery, reduce the likelihood of injury and avoid low-energy availability (LEA).
Use multiple transportable carbohydrates when ingesting more than 60g of carbohydrates per hour.
Start experimenting in training with pre-race and race-day nutrition multiple times during training before the big day arrives
We all know those stories of athlete's who race experience was ruined by unwanted GI upset. Set your self start training your gut during training by practicing your fueling and fluid strategy early and often! Don't let your gut be the thing standing in the way of all your hard work on the big day!
READ MORE:
Sport Nutrition, Third Edition. (2019) by Asker Jeukendrup, Micheal Gleeson
Multiple transportable carbohydrates and their benefits (Jeukendrup, 2018)