Nutrient timing – time when you eat to level up your performance?

So you have been nailing your diet and training consistently but want to level up your performance? This is where when you eat can make a tangible difference.

As usual, some science is included, but feel free to skip to the sections that you want.

Table of contents:

• Debunking the myths
• So does nutrient timing matter?
• How does nutrition influence performance and recovery?
• So does it matter when I eat around my training?
• Nutrient timing matters more
• Nutrient timing matters less
• Pre, post, intra workout nutrition?
• Take aways

Debunking the myths

Popular claims made around nutrient timing include:

1. Protein should be consumed immediately post training to maximise the advantage of a post anabolic window
2. Nutrient timing can prevent fat gain
3. Nutrient timing can have a greater impact on body composition than total daily nutrient intake

Debunking the myths:

1. Protein should be consumed immediately (<1 hour) post training to maximise the advantage of a post anabolic window

Whilst some research indicates that there is a post-exercise window (1), this ‘window’ of opportunity, appears to be greater than 1 hour.

Additionally, hitting your daily protein intake comes before any timing!

A single bout of resistance exercise can increase muscle protein synthesis (MPS) for up to 24-48 hours and protein intake distributed throughout this period is relevant for training induced mass gains in muscle hypertrophy.

(7)

Protein timing may still be relevant for protein distribution due to the muscle full concept – the idea that there is a ceiling on how much protein can be used for MPS at one time. This is suggested to be about 20-40g of protein, over an approximate 3 hour period. (8,9).

Research indicates that consuming a high-quality protein such as 20-25g whey or 6g essential amino acids (EAAs) pre-workout can elevate muscular uptake of AA for up to 4.4 times and that levels do not return to baseline until 3 hours following workout (11).

If you eat a protein rich meal 3-4 hours pre workout, you ideally need to consume protein as soon as possible post training – if we are have the goal to optimise recovery and body composition.

2. Nutrient timing can prevent fat gain

This claim is based on the idea that nutrients, specifically carbs, are less likely to be stored as fat immediately post workout due to glycogen depletion and glucose use during a workout (resistance, high-intensity or > 90 mins endurance).

On a short-term basis, it maybe that available nutrients will initially be less likely to be stored as fat as they will be utilised to restore glycogen.

However, on a long-term (24 hour) basis, providing overall energy balance remains similar and only nutrient timing differs, the net difference will be zero –

• glycogen replenishment can occur with carbs or fats (carbs quicker/easier)
• gaining fat requires being in an energy surplus over time(this can come from carbs or fat)

Fat gain can only be prevented by consistently being at energy balance.

3. Nutrient timing can have a much greater impact on body composition than total daily nutrient intake

Body composition is influenced by energy balance, training stimulus and protein intake. To reduce fat stores, requires creating an energy deficit – most readily achieved through creating a calorie deficit!

Physical activity can also increase that energy deficit. Likewise, to increase fat stores, requires an energy surplus.

To increase muscle mass and strength requires following a progressive resistance training programme, hitting your daily protein intake and having enough calories (12). The amount of muscle mass and rate you wish to build it at, along with your current levels of bodyfat and training experience, will determine how much of an energy surplus you need to be in.

Therefore resistance exercise, followed by energy and protein intake, are the most important factors for influencing body composition.

So does nutrient timing matter?

Whilst a meta-analysis of nutrient timing concluded that the 1-hour post-anabolic window may not stand, nutrient timing still matters – especially if you are training regularly.

In general, space calories and protein by no more than 3-4 hours around training, so you have sufficient calories and protein availability.

Reminder of how nutrition influences performance and recovery

Exercise requires sugar (glucose) to generate energy (ATP) – this can deplete muscle glycogen levels and trigger muscle protein breakdown (13). Calorie and nutrient availability around training can therefore influence our capacity for output, as well as replenishing stores/

Performance

Times when you may deplete glycogen stores:

• resistance training: depending upon intensity, volume and duration (15).
• endurance training > 90 mins and high-intensity aerobic training (>70% VO2 max)

Consuming carbs pre and intra workout can provide an immediate source of sugar to fuel the workout, benefit performance and reduce fatigue.

Thus the immediate post workout shake is less relevant for glycogen repletion. Since glucose is the preferred fuel for the body, to restore glycogen rapidly, a carbohydrate based meal would be optimal.

Recovery

Glycogen depletion is associated with fatigue and reduced levels of performance. Rates of glycogen repletion are faster immediately (2-4 hours) post workout (18) due to increased insulin sensitivity and exercise-induced muscle responsiveness.

But stores can be normalised within 24 hours (unless you have severe muscle damage) and it will not make a difference whether you replenish levels immediately or within your window (18) – unless, you are training again that day or you trained in the evening and are training first thing in the morning.

Whilst research indicates that the addition of carbs to protein post workout may not increase MPS, it may reduce muscle protein breakdown (MPB). Since muscle protein synthesis is a balance between muscle protein synthesis and muscle protein breakdown, levels of glycogen may therefore influence the repair of muscle fibre and recovery levels.  

Additionally since consuming 20-40g dose of protein every 3-4 hours is optimal for MPS, having one of your protein doses will likely be necessary at this time.

Additionally, the stimulus for recovery may be stronger in the hours immediately following training and avoiding entering a catabolic state is a priority.

• Consume a protein rich meal/snack within 3-4 hours of your last meal/snack pre workout. Protein shakes/milk are a useful way to ensure you are meeting your protein intake post workout, whilst hydrating.
• Consume enough carbs within a 24 hours period to replenish glycogen levels or sooner for your next workout. Post workout is an ideal opportunity to have your second fruit.

So does it matter when I eat around my training?

Whilst that immediate 1-hour post-anabolic period may not be as crucial as once believed, eating within a certain window around training is still relevant to optimise recovery and future performance.

Since a protein-rich meal has a limited anabolic impact of approx. 3-4 hours, overall daily meal patterns will influence nutrient timing. Additionally, the extent to which it matters will depend upon you as an individual!

It matters more if: you are an elite athlete, you are training multiple times per day, you have especially low body fat levels, you are in a calorie deficit, your goals include building muscle / optimising performance), you train fasted.

It matters less if: you have a regular meal schedule with meals spaced out approx. every 3-4 hours which enable you to meet your total nutrient intake, you have excess body weight, if you train less regularly / intensely.

The most important factor alongside your training is meeting your daily energy needs, as well as macro and micronutrient intake. Ensure that you are doing this consistently before considering nutrient timing!

Who nutrient timing matters more for:

Elite athletes: to optimise performance and recovery. The appropriate intake of carbs and protein, along with electrolytes can make a tangible difference when you are consistently eating and training well

For muscle building: to optimise MPS and create an anabolic environment to translate this to muscle mass gains.

For fat loss: to help muscle retention and fat loss.

When training multiple times a day: to replenish glycogen levels, prevent lean muscle breakdown and aid recovery.

When endurance training >90 mins: to replenish glycogen levels, prevent lean muscle breakdown and and aid recovery.

If you have low body fat: adequate fuel around training may prevent going into breakdown state.

If you are training in a calorie deficit: as above – this means levels of hormones are altered e.g. sex and stress hormones.

If you are training in a fasted state: as above!

If your pre-workout meal was 4-6 hours pre workout: as above! You may have entered a fasted like state.

Nutrient timing matters less:

If you’ve consumed a pre-workout meal right before your workout: even if this is a simple protein shake or some EAAs then you will have the supply of amino acids to fuel the training session and support MPS.

If you’ve consumed a mixed pre-workout meal 1-3 hours pre-workout: then you should be within the window necessary for circulating levels of nutrients from a meal to reach its peak and be in an anabolic state.

For short / low intensity sessions: glycogen levels will likely not be depleted and the breakdown of muscle may have only occurred at a low level.

Pre, post, intra workout nutrition?

The purpose of pre workout nutrition is to fuel the workout so that performance can be optimised. It also creates an anabolic environment to maximise MPS.

Post workout nutrition may aid recovery – rates of glycogen resynthesis are higher in the immediate hours post workout, it can provide available amino acids for MPS and create an overall anabolic environment conducive for recovery.

Choice of post workout nutrition will depend on pre workout nutrition, as well as you as an individual, your goals and overall meal schedule!

Intra workout nutrition may also be beneficial for some of the individuals specified above – such as those who are engaging in longer durations of training and / or multiple training sessions.

Takeaways:

Claims that nutrient timing can prevent fat gain and influence body composition are false: overall energy balance and resistance exercise will influence whether an individual gains fat or not and what their body composition is.

Muscular adaptations take place over a longer period than <1 hour post training: and may not be so relevant when you are having regular nutrient intake every 3-4 hours, meeting total energy and protein requirements, and distributing protein appropriately between meals.

Timing nutrient intake around training can optimise performance and recovery: and may be more relevant for certain individuals – elite athletes, individuals who train multiple times a day, those who are lean or in a calorie deficit or train fasted.

Related articles:

Will fasted cardio benefit my training performance?

Does protein distribution matter for maximising your muscle gains?

What are your experiences with nutrient timing? Have you noticed how timing your nutrition impacts your training, performance, recovery? Would love to hear about your experiences in the comments below!

References

1. Esmarck et al. (2001). Timing of postexercise protein intake is important for muscle hypertrophy with resistance training in elderly humans.
2. Verdijk et al. (2009). Protein supplementation before and after exercise does not further augment skeletal muscle hypertrophy after resistance training in elderly men.
3. Willoughby et al. (2007). Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass and strength.
4. Hulmi et al. (2009). Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression.
5. Eskine et al. (2012). Whey protein does not enhance the adaptations to elbow flexor resistance training.
6. Aragon & Schoenfield (2013). Nutrient timing revisited: is there a post-exercise anabolic window?
7. Damas et al. (2016). Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage.
8. Moore et al. (2009). Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men.
9. Macnaughton et al. (2016). The response of muscle protein synthesis following whole-body resistance exercise is greater following 40g than 20g of ingested whey protein.
10. Bohe et al. (2001). Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids.
11. Tipton et al. (2007). Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise.
12. Morton et al. (2020). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.
13. Kerksick et al. (2017). International society of sports nutrition position stand: nutrient timing.
14. Lambert et al. (2002). Fatigue during high-intensity intermittent exercise: application to bodybuilding.
15. Roy et al. (1998). Influence of differing macronutrient intakes on muscle glycogen resynthesis after resistance exercise.
16. Hawley et al. (1997). Carbohydrate loading and exercise performance.
17. Hargreaves et al. (2004). Muscle glycogen and metabolic regulation.
18. Burke et al. (2004). Carbohydrates and fat for training and recovery.
19. Lemon et al. (1980). Effect of initial muscle glycogen levels on protein catabolism during exercise.
20. Capaldo et al. (1999). Splanchnic and leg substrate exchange after ingestion of a natural mixed meal in humans.