The diet low carbohydrate high fat (LCHF) has gained a lot of attention for their potential role in weight loss, especially for people with insulin resistance and type 2 diabetes. Although weight loss in these populations may be desirable, what are the consequences for athletes and sports performance? It is possible to receive or even improve performance on LCHF diet?
In an effort to learn more, I recently visited a low carb-high-performance-seminar (26.11.14) organised a syndicate for low-carbohydrate diets (low carb down under - site here). For those interested, below is a summary of the event and my impression of LCHF for sports performance.
What is exactly a LCHF diet?
There is no 'one' LCHF-diet; There are many variations, such as with any diet. At the core of LCHF is similar to the well-known Atkins diet and carbohydrate intake is limited to a level that forces the body into ketosis. This means that fat (instead of carbohydrate) is the predominant fuel for the brain and muscles. The main point of difference is that unlike the Atkins Diet a LCHF not necessarily a 'high protein' diet.
After guest speaker, Dr. Stephen Phinney, it takes about two to three weeks for the body to achieve ketosis. During the first week of people complaints you often have nausea, weakness and ease fatigue. Once the body begins to adapt with fat as the dominant fuel, the symptoms usually disappear. First weight loss is common, but is usually a loss of water and glycogen (storage form of carbohydrate) due from the body.
LCHF means a drastic reduction of carbohydrate-rich foods in our diet such as grains and cereals, starchy vegetables, most fruits and dairy products and almost all processed foods. In its most extreme carbohydrates limited less than 30 g / day (which is about half ACUP rice or a large banana) with less restrictive regime, so that up to 75 g / day.
To reach excellence on LCHF?
In the Phinney 1983 active individuals were studied and cyclist trained a LCHF-diet, lead to ketosis before performing a series of exercise tests. During the first week, subjects reported a decrease in energy levels during training at 65% of VO2max (the maximum amount of oxygen, which can use an individual during intensive training). After 4 weeks of adjustment to a ketogenic diet could topics to get sub-maximum performance with an increase in triglycerides (FAT) use.
Exercise at this intensity be relevant during the duration of the training or competition, but what happens if we need to perform above this threshold? After connecting the LCHF diet for four weeks, a decreased ability of Sprint had issues during maximum exercise compared to the baseline. The authors concluded, sub-maximum exercise LCHF diet could be maintained, but performance is degraded during high-intensity exercise.
Practical applications of LCHF
Darren Burgess, the high performance manager for port Adelaide Football Club provided an insight into the experience of several players who have experimented with LCHF. A player to improve his aerobic capacity want to chose a paleo diet in addition to an increase in the professional exposure to follow (not the Phinney LCHF regime outlined). The player was followed by a 'cyclic paleo' regime (carbohydrate intake on some days and others do not restrict) while conducting three additional aerobic-based sessions per week. With this in mind, improving its 3 km time-trial around alone diet should be attributed to.
Two other players testing LCHF lost eight and ten kilograms during the season. One of the players has been specially aimed at weight loss while the other by hip operation was recovered and was still for the start. It is worth noting that a reduction of in body weight indicate also a loss of muscle mass, which is certainly not desirable, that most athletes. Unfortunately, no pre or post were measured performance values of the strength or exercise.
Melbourne Football Club doctor, Zeeshan Arain was the record straight about the recent attention of the media speculate that the whole playing Group had accepted a paleo diet. It seems players were presented with the option of switching to a paleo diet, but thoughts about nutrition as part of the performance, and to promote the consumption of wholefoods, the focus was to players. More specifically, the exclusion of processed foods would shift to a lower carbohydrate higher low-fat diet with players still consumes plenty of carbohydrates to game day lead.
Ultimately it is up to you
Despite the overwhelming evidence for the benefits of carbohydrate on athletic performance, the traditional carbohydrate-based diet is not the only choice for athletes. It seems sub-maximum exercise performance can be maintained after an initial adjustment, which targeted weight loss may be desirable for some athletes, especially those. Training for elite athletes regularly over 65% VO2max is likely affect a LCHF diet. Ultimately should be considered performance targets and individual preferences, prior to the adoption of a LCHF diet.