Want to Improve your Performance? Manage your Carbohydrates

Carlos Sánchez 6 min. of reading Fitness Leave a comment

In this article, you’ll discover the importance of playing with carbohydrate amounts to maximise your performance.

If you’ve followed me for a while, you’ll know that I’m a big fan of cycling both calories and carbohydrates.

As I’ve written in some articles before, following a low-carb days protocol with 1-2 days of REFEEDSs (days with high carbohydrate intakes) helps improve fat loss thanks to its effect on T3 and leptin (among other factors).

In terms of performance, it’s no different, as the expression of certain proteins depends on the (non-) presence of carbohydrates.

Index

1 Carbohydrates and Type of activity
2 Cellular expression and training
3 Post-workout Carbohydrate Suppression
4 What about post-workout protein?
5 Athletes with type I fibres
6 Conclusions
7 Bibliographic Sources
8 Related Entries

Carbohydrates and Type of activity

Carbohydrates play an important role in training, especially in two specific situations:

Long-duration training (+ 3 hours), such as with people training for a marathon or Ironman.
High-intensity workouts (above 80% VO2max), where glucose consumption at the cellular level skyrockets.

However, for endurance athletes, it’s good to use both metabolic pathways, both fats and carbohydrates.

What’s known as “metabolic flexibility“. You’ll find an extensive analysis of this concept in this link.

For this, the cell (especially the mitochondria) must be efficient when using the different substrates.

When carbohydrates are restricted, a greater expression of enzymes related to the oxidative capacity of the cell (1) is achieved, in other words, it favours the use of fat as an energy source.

This phenomenon is due to the fact that when we have a low amount of glycogen (glucose), a series of mechanisms are put in place that can save glucose by using more fatty acids, although as they show in this study, “it does not translate into higher performance during high intensity exercise”.

Cellular expression and training

Muscle contraction (especially weights) is a powerful stimulator of gene expression related to the synthesis of mitochondria (greater number of mitochondria, greater performance), in addition to providing other benefits at the muscle level.

An example of the latter is seeing how the deep squat helps improve running performance (2).

At a mitochondria level, the training acts in four ways , with 2 of particular interest:

Control of the expression of mitochondrial DNA genes by the transcription factor Tfam
Mitochondrial fission and fusion mechanisms

Tfam (mitochondrial transcription factor) is genetically determined and is related to higher aerobic performance (such as cyclists, swimmers, marathoners…etc.), where the higher the Tfam, the higher the performance (4).

And the fusion of mitochondria helps the muscle become much more “effective” when using energy (5,6). Training, along with low-carb diets, helps increase this process.

When mitochondria fusion decreases, the likelihood of muscular atrophy increases

When we reduce the presence of carbohydrates, there is an increase in the levels of AMPK (through which the body seeks energy) and a protein called “p38”. Both factors help increase the fusion and synthesis of new mitochondria (7,8,9), which will help increase the post-training mitochondrial response.

Post-workout Carbohydrate Suppression

This study (10) shows how the intake of carbohydrates or post-training placebo affected the expression of proteins related to the synthesis of mitochondria (where the p38 that I just mentioned is found).

HI-LO = SUBJECTS WHO CONSUMED PLACEBO POST-TRAINING

HI-HI = SUBJECTS WHO CONSUMED POST-TRAINING CARBOHYDRATES

The expression of p38 was much higher in the group that consumed post-workout placebo during the afternoon training session than in those that consumed carbohydrates.

My personal opinion is that the intake of carbohydrates or fats lower the AMPK pathway, altering the “adaptation” generated by training.

What about post-workout protein?

Other studies have found that this does not occur with post-workout protein.

In view of this, we can see how delaying post-workout food can be an excellent option for starting the mechanism of mitochondrial synthesis.

Athletes with type I fibres

If we focus on the type of fibre, the most beneficial are those of type I, as the presence of mitochondria and oxidative capacity is very high.

What athletes have a high number of these fibres?

If you look at the dat, those with the most type I fibres are people who do marathons, swimming, cross-country running…etc.

It is in this group of people that the most benefits will be seen when increasing the number and size of mitochondria, as they’ll generate more energy from less substrate, what I call “metabolic effectiveness“.

This means that the athlete will delay the onset of muscle fatigue by making less use of glucose.

Conclusions

Although carbohydrates play an important role in recovery, delaying post-workout intake (2-3 hours) in some of the workouts can be a valid technique to favour the adaptation generated by training, even when the person carries out a second workout that same day.

As I always say, the best way to improve performance is using both fuels, don’t base your peri-training on only carbs or fats. Your muscles will thank you.

Cheers! S.Espinar