It’s January, the first month of the new year and the ideal time to stop and think about your goals for the year! Once your 2017 goal is set, it’s time to start thinking about how you should fuel for your best performance. How to fuel for endurance goals is critical. What many athletes don’t understand is that your fueling strategies for training and racing should differ. Fueling for training should support optimal training adaptations while race-day fueling should support maximal performance.

There’s a school of thought called ‘Train-Low’

When carbohydrate is restricted, enhanced training adaptations are commonly reported, termed ‘train-low’. Training ‘low’ appears to enhance fat metabolism and may improve exercise capacity. If race-day fueling is optimal, these enhanced training adaptations can improve race-day performance.

Despite the potential benefits of training ‘low’, there are negative implications of persistently training ‘low’:
• The desired training intensity is unlikely to be maintained because carbohydrate is the primary energy source for high-intensity exercise.
• Immune system functioning can be suppressed, increasing the risk of illness.
• Muscle protein breakdown is increased. Continually raised muscle protein breakdown can reduce overall muscle mass, which will reduce power output and exercise performance.
• The body can no longer utilize carbohydrate as effectively during high-intensity exercise, decreasing race-day performance.

And then there is ‘Train-Smart’

A recommended approach to overcome these negatives is ‘Train-smart’, a periodized approach to carbohydrate intake rather than ‘train-low’. ‘Train-smart’ recommends that an athlete fuels for the work required. Carbohydrate can be restricted for selected training sessions aiming to enhance training adaptations. When the goal is to perform the highest workload possible, a restricted carbohydrate approach isn’t appropriate. In sessions lasting 60-90 minutes or less, performed at a low or moderate intensity, training ‘low’ is likely to be beneficial.

Multiple ‘train-smart’ strategies that appear to enhance training adaptations are reported in scientific literature:
• ‘Sleep-low & train-low’ uses overnight carbohydrate restriction followed by a moderate-intensity, ‘train-low’ session in the morning. Beforehand, high-intensity sessions are performed in the afternoon/evening after consuming carbohydrate during the day.
• ‘Twice per-day sessions’ suggests training twice per-day every other day rather than once every day. The second session of the day is a ‘train-low’ session, having restricted carbohydrate intake following the first session.
• During a ‘train-low’ session, carbohydrate should also be restricted, as consumption of carbohydrate during training appears to blunt enhanced training adaptations.
• ‘Train-low’ sessions should be protein-fed rather than fasted to reduce muscle protein breakdown.
• Consuming caffeine before a ‘train-low’ session appears to increase exercise performance by mitigating some of the loss in exercise intensity observed when carbohydrate is restricted.

So what about Race-day?

When maximal performance of high-intensity exercise is desired, high carbohydrate intake is key because carbohydrate is the primary energy source for high-intensity exercise. Contrary to popular belief, one day of carbohydrate loading is just as effective as three days. Therefore the day before race-day, we recommend consuming 8-10 grams per kilogram of body mass of primarily high GI carbohydrate such as white bread or SiS GO Isotonic Energy Gels.



To maximize performance and carbohydrate loading, training should be tapered leading up to race-day. Tapering should begin two weeks prior to race-day with a steady reduction in training volume. The final training session should take place in the afternoon/evening two days prior to race-day and carbohydrate loading can begin with the post-training meal.
On race-day:
• Large quantities of fiber, protein, fat, and fructose should be avoided as these have been associated with stomach problems during exercise. Individual preference is also important.
• The pre-race meal should contain some carbohydrate, however if the individual is sufficiently loaded the day before, it doesn’t have to be especially high in carbohydrate.
Carbohydrate consumed during a race provides an alternative source of energy to muscle glycogen and is used as fast energy. Carbohydrate should also be consumed following high intensity and/or during long duration exercise to replace used muscle glycogen to enhance recovery.

Summary of Recommendations

‘Train-low’ sessions…
• Only for moderate or low intensity training lasting less than 60-90 minutes
• Consume protein beforehand rather than being fasted
• Consume caffeine approximately 20 minutes beforehand

Performing carbohydrate loaded…
• For high-intensity training and/or sessions lasting longer than 60-90 minutes
• For events lasting longer than 90 minutes consume 8-10 grams per kilogram of body mass of mainly high GI carbohydrate the day before race-day
• Consume 60-90 grams of carbohydrate every hour during a race, aiming for 20 grams every 20 minutes, e.g. an SiS GO Isotonic Energy Gel
• Consume 1.2 grams per kilogram of body mass of carbohydrate following high-intensity and/or long duration exercise


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