Train Low, Compete High
Matt Durkin explains why athletes are now choosing to adopt a periodised approach to their nutrition, just like they do with their training.
Since the landmark 2005 study of Hansen and colleagues, it has been well-known that the body's availability of carbohydrates can influence how we adapt to exercise training.
These preliminary findings have stimulated further investigations and shaped a training ideology known as "train low, compete high". Otherwise known as 'carbohydrate periodisation' or 'fuelling for the work required, this is, in essence, a way of inducing more incredible training adaptations by manipulating carb intake (train low). However, athletes should always perform with optimal carbohydrate stores and adhere to an appropriate fuelling strategy (compete high).
Evidence suggests that specific training sessions with low carbohydrate stores drive adaptations to fat metabolism. This allows athletes to burn more fat at a given exercise intensity and, therefore, fewer carbs. As carbs are more efficiently used, they are preserved later in an event, such as during hill climbs or sprint finishes. This is something commonly known to sports scientists as metabolic flexibility.
Many athletes are now choosing to adopt a periodised approach to their nutrition, just like they do with their training. One of the most publicised of these athletes is 4-time Tour de France winner Chris Froome, who believes this approach has helped his athletic development and weight management.
Now that we have touched on training low and competing high, let's quickly review key research findings.
The Research
In 2005, researchers wanted to assess whether training twice every other day was more effective than training once every day. In a group of healthy but untrained men, one leg was trained daily using the leg extension exercise, while the other leg was prepared twice every other day using the same activity.
The recovery period in the leg that trained twice every other day was lacking in carbohydrates. The day's second session was performed with low carbohydrate availability.
After a 10-week training block, the leg that trained twice every other day saw greater resistance to fatigue, increased muscle glycogen stores, and an upregulation of key enzymes involved in fat metabolism. Despite some limitations in the study, such as using untrained individuals, these fascinating findings inspired further work.
For many years, many studies have looked at the benefits of twice-daily training in running and cycling. Again, the second session of the day was with low carbohydrate availability. Interestingly, these studies agreed that this training method led to impressive muscle adaptations, but this rarely translated to an improvement in performance.
These results came about because the study participants were instructed to perform high-intensity interval training whilst deficient in carbohydrates. As this activity is almost exclusively fuelled by glucose, the performance drops in the training sessions were substantial. None of the studies found that 'training low' worsened performance during a simulated time trial event.
A further study conducted at Liverpool John Moores University in 2014 found that training low led to 'time-efficient' training adaptations. It means those training low saw impressive training adaptations as those who always trained with high carbohydrate availability. Despite those in the "train low" group performing much lower training volume was realised. Again, though, there was no benefit to performance.
More recent work has employed the 'sleep low' approach. In this approach, athletes complete an exercise session in the evening and restrict carbohydrate feeding afterwards, thereby sleeping with reduced carbohydrate availability. The following morning, the athletes perform a low-intensity session in their fasted state.
This method has been shown to induce favourable adaptations at a cellular level, but this has also translated into improved exercise performance. A study from 2016 showed that in as little as three weeks, 'sleeping low' led to a group of elite triathletes/cyclists improving cycling efficiency (3.1%), 20km cycling time trial performance (3.2%), and 10km running performance (2.9%) when compared to a traditional diet of chronic high carbohydrate availability. What is more is that these athletes lost more body fat, thus improving their power-to-mass ratio.
I hope future investigations build upon these findings and uncover the best 'training low' method for boosting exercise performance.
The Different Ways to Train Low
We have highlighted the merits of performing specific training sessions under conditions of low-carb availability. Some of you may be wondering how best this could be completed. It is accepted that there are numerous ways to do it, each of which we will describe below.
Low Carbohydrate Diet
There are many types of low carbohydrate diets, but they all ultimately restrict carbohydrates and see an increase in fat and, more often than not, protein. Despite much attention, a chronically low carbohydrate diet is not recommended for athletes required to train and perform at high intensities.
Firstly, a chronically high fat intake reduces the body's ability to use carbohydrates for fuel. Although glycogen may be spared on this diet, it cannot effectively be used.
Furthermore, fat is a less efficient fuel source than glucose/glycogen. It means that athletes on a low carbohydrate (and thus a high fat) diet use more oxygen for a given intensity. Naturally, this decreases exercise economy, a key determinant of performance during endurance exercise.
Twice Per Day Training
Training twice a day is the method used mainly in this area of research. Although most studies have failed to see an increase in performance, the second session of the day has been an interval-type session that has demanded high-intensity efforts. As we know, this has performance repercussions when completed with sub-optimal carbohydrate stores.
Alternatively, it is proposed that those wishing to embark on this method perform a high-intensity session in the morning under optimal carbohydrate availability and a lower-intensity session later in the day following carbohydrate restriction.
Long Training Sessions Without Carbs
Current sports nutrition guidelines recommend consuming 30-60g of carbohydrates per hour during sessions exceeding 90 minutes. Up to 90g per hour is often recommended for training sessions exceeding 3 hours.
By restricting carbohydrate intake, muscle and liver glycogen stores will become depleted, increasing the stimulus for training adaptations. However, this will also increase perceived exertion, as the athlete will have to dig deeper to maintain training intensity.
Sleeping Low
Sleeping low is characterised by an evening exercise session designed to lower glycogen stores. The following morning, a low-intensity session is performed without the ingestion of carbohydrates. As discussed, this is a relatively new approach to training low and one that appears to have merit. Due to the nature of the training sessions, the lack of carbohydrates seems to exaggerate training adaptations.
Fasted Training
It is the least complicated training method, and athletes often consume black coffee before training. Eating a breakfast containing protein and fat does not negate the benefits.
No Carbs During Recovery
Traditionally, consuming a rich carbohydrate source at least once within two hours of exercise is recommended. The body is primed to replace glycogen stores within this timeframe. However, prolonging the time in a low carbohydrate state can accentuate the adaptations to training, while the trade-off is a slower recovery time.
The Downsides to Training Low
While it is important to understand that not all studies have seen a performance improvement, it is also important to mention that there are certain downsides to training low. As mentioned previously, carbohydrates are the primary fuel source for exercise. So, it should not surprise that performance at high intensities is impaired.
Even when low-intensity sessions are performed, it is well accepted that the athletes perceive themselves as working significantly more complexly to maintain the required intensity and achieve the training volume.
Furthermore, it is well-known that high training volumes can impair immune function. As carbohydrates fuel immune cells, providing the body with adequate carbohydrates can help keep illnesses at bay.
Although the only research study in this area has shown that low training does not lead to more illnesses than regular training, athletes who often suffer from diseases may be wise to limit the low training they complete.
Finally, regular training without taking on carbohydrates can affect the ability of the gut to absorb and utilise this fuel source seamlessly. Research has shown that the gut can be 'trained', as it can become accustomed to taking on large boluses of carbohydrates whilst exercising at high intensities. Fueling correctly during endurance events without suffering stomach upsets is a crucial performance aspect.
For the above reasons, it cannot be stressed enough that low-level training should not be done too regularly. Instead, it should be incorporated into the mesocycle, a phase where optimal performance and fast recovery are not paramount.
Strategies to Negate Dips in Training Performance
Certain nutrition strategies can help maintain training intensity while training low. The first of these is caffeine, one of the most researched supplements in sports nutrition.
The research is almost unanimous in favour of caffeine's ability to improve endurance exercise performance. For most athletes, taking ~200mg 30-60 minutes before exercise will suffice.
Secondly, carbohydrate beverages do not need to be consumed to elicit a performance benefit. Research has consistently shown that swilling a carbohydrate solution in the mouth for 5-10 seconds and then spitting it out increases performance as it positively influences the reward centre in the brain. A 2-3% performance benefit is often noted in the literature.
Interestingly, there is a scientific study to validate these strategies, as trained cyclists were able to perform much better when using caffeine and carbohydrate mouth-rinsing while training low.
Summary
The role of carbohydrates in exercise performance is a topic that has been fascinating to exercise physiologists for over 100 years since it was first investigated. Despite training, low being a relatively new topic in the field, and further investigations are of course warranted, there are some conclusions we can confidently come to:
Training under low carbohydrate availability increases exercise adaptations and, when performed correctly, can improve exercise performance. Competitions should always be performed with optimal carbohydrate stores.
The approach to adhere to for best results is fuelling the work required. It ensures that the athlete can perform optimally during high-intensity sessions and then promote adaptations in low-intensity sessions when high carbohydrate availability is not paramount.
It is accepted that there are numerous ways to train low, each with similarities, differences, strengths, and weaknesses.
Training low should be used sparingly to induce adaptations when performance and recovery are not the primary focus. It is because, among other limitations, it can worsen performance and delay recovery. Caffeine supplementation and carbohydrate mouth-rinsing can partially negate performance decrements.
Page Reference
If you quote information from this page in your work, then the reference for this page is:
- DURKIN, M. (2018) Train Low, Compete High [WWW] Available from: https://www.brianmac.co.uk/articles/article359.htm [Accessed
About the Author
Matt Durkin, MSc, is a principal nutritionist at Simply Supplements. With extensive sports nutrition experience, Matt advises on new product formulations and provides tailored nutrition to clients.