Preparation phase	Performance phase
This is the time to implement carbohydrate periodisation (see next slide)	This is the time to increase carb intake to the higher end of the range more consistently
This is the time to focus on body composition changes (both losing fat or building muscle)	You should be trying to stay weight stable in this time.
You can be more aggressive with your diet as it is further from the event.	Eating at maintenance or in a slight surplus.
Training can be manipulated to align with this.	Practicing nutrition habits that are going to be replicated on event day
This is the time to add more variety in the diet	Time to focus on less variety and more consistency

 

Metabolic flexibility

Metabolic flexibility for endurance refers to your body's ability to efficiently utilise burning carbohydrates and fats for energy depending on the demands of exercise.

To improve this, you can manipulate carbohydrate intake and focus on specific training sessions. The goal is to shift the graph.

Making you more efficient and not needing to grab the gummy bears after 5km.

Carbohydrate periodisation

Manipulating carbohydrate intake (especially during the preparation phase) can enhance AMPK signalling, increase GLUT-4 activation, and improve mitochondrial function, leading to better aerobic adaptations.

There are a number of ways to achieve this (see below)

• Train-low sessions must be low intensity.
• Chronically low carbs can raise cortisol, weaken immunity, and break down muscle so do on low to moderate sessions.
• Harder sessions always fuel with carbs.

The amount of protein needed for endurance athletes

A habitual protein intake of 1.5 g/kg of body mass (BM) 1·day-1 is typical in male and female endurance athletes (sometimes even less than this in my anecdotal experience with athletes)

Based on findings from a series of recent protein requirement studies, the evidence suggests a daily protein intake of ~ 1.8 g·kgBM-1·day-1 should be advocated for endurance athletes.

Protein requirement may be further elevated in excess of 2.0 g·kgBM-1·day-1 during periods of carbohydrate and energy restricted training and on rest days [4, 5, 6]

Protein distribution

It is advised to try to distribute protein intake evenly to help maximise protein synthesis.There is research to suggest that larger single intakes of protein can mitigate the need for this.

However, from a practical perspective, I still advise trying to distribute more evenly.

Aiming for 0.3-0.5g/kg in main meals and using snacks and recovery drinks to top up is advised [7].

This graphic shows an example day of hitting 1.8g/kg of protein.

Fats and food quality

From an energy source to supporting an optimal hormonal environment and driving metabolic adaptations, quality fats are crucial for the endurance athlete. 

Recent research has shown that although runners met or exceeded protein recommendations, their carbohydrate intake fell short of endurance-specific guidelines, whilst total dietary fat intake exceeded recommendations (excluding long-chain polyunsaturated fatty acids).

Diet quality scores averaged 63.1 out of 100, with a high intake of discretionary items [8].

I have observed the same pattern. So I encourage you to think about the following - 

• Where are your fats coming from? Is it junk food and peanut butter or are there good quality sources?
• Are you overeating fat at the expense of carbs?
• Are you timing fat correctly (away from the training window)

Key nutrients for endurance

Fuelling training sessions

The key principles to follow

• The closer you get to your session the more liquid-based your nutrition should be.
• Low fibre, high carb. This is the focus.
• The longer the session, the more you should eat BUT do not chase this right before the run. Make sure you are eating enough in the meals / day before.
• The ranges are there to play around with. Longer more intense session - edge to the higher amount.
• You can split the amount of carbs into the two feeds before. For example if you need 50g you can eat 35g at 90 minutes pre and 15g of liquid carbs in the 30 minutes pre run.

 

It is also useful to practice the products that you will use during your event.

• Gels - check out the unflavoured (to help reduce sweet fatigue) and mixed berry gels from MARCHON here.
• Bars
• Hydration
• Snacks
• Chews

As you get closer to your event you want to remove as much of the decision stress around nutrition as possible.

Gut training 

Gastrointestinal distress is widely reported as one of the primary reasons people fail to finish endurance events [9].

The thing is it can be prevented.

Ultra running places significant stress on the gut with butyrate levels dropping, intestinal barrier function being comprised alongside the practical issue or trying to digest large amounts of food, optimal gut function is crucial.

Check out this article on gut training.

Next up in the series is Ultra race day nutrition

This will cover -

• Common mistakes
• Carbohydrate loading
• Pre-event meal
• Intake during the race
• Advice for different length ultras
• Hydration strategies

Check this article out here.