Thursday, 21 October 2010

Cutting weight without crash diets and dehydration

When considering the optimum nutritional plan for BJJ it is first important to consider the energetics and physiological demands of the sport.
I will begin by analysing the energy demands of a typical training session. Based on this I will give information on how to calculate your daily calorie, protein carbohydrate, and fat requirements. I then briefly talk about pre and post training nutrition needs and how these differ when maintaining weight and cutting weight. Finally I will talk about the dangers of cutting weight by crash or dehydration methods.

Training session
A typical training session can be anywhere between 1-2 hours long and in most cases will involve a warm up which includes a mix of running, breakfalls, and other acrobatic and gymnastic type movements to warm up all muscles of the body and prevent the risk of injury during sparing/rolling/grappling part of the class.
15-30 minutes of this type of activity when performed at an intensity of 70-80% of heart rate maximum is likely to burn around 100-300kcal depending on size and how hard you or your coach dictates.

This is usually followed by static and dynamic stretching and drilling certain techniques or movements and usually lasts 30minutes to 45 minutes often preformed at a lower intensity of 50-60% heart rate max. Again maybe 100 calories or so are burnt depending on what is being drilled.

The most demanding part of training usually occurs while rolling which is usually sparing from the knees against an opponent for an average of 5 minutes, this can go on for 30 minutes to an hour in an intermittent or continuous pattern depending on how fit you are/mat space.
The intensity while rolling can vary depending on sparing partner and is hard to measure with a heart rate monitor, however while browsing through studies of other martial arts including wrestling and judo it would appear that this type of high intensity activity could burn anywhere between 400-800kcal and hour.
Gives an average estimate based on weight bare in mind this is probably the calories burnt when sparing only.

Simply put, the demands of training BJJ are pretty high! My estimate is that after a good 15-30 minute warm up, 30 minutes of drilling and 30 minutes of rolling the energy expenditure during a typical session could would be between 600-1000kcal for someone my size possibly more for heavier guys! This type of work out requires muscle glycogen stores to be full at the beggining to avoid the onset of fatigue during training, and immediate replenishment after, espacially for those of you who are training everyday or more frequently.

Nutrition for general training
It is essential when training and competing to think of the food you eat as fuel, in order to perform to the best of your abilities your body needs to be hydrated and your muscles need a good supply of energy provided by carbohydrates. The recommendations I make are based on common principles of sports nutrition that will provide you with enough energy to have good training sessions and aid you in your recovery between the next sessions.
First step Calculate basal metabolic rate BMR

Women weight in kg x 22
Men weight in kg x 24

This figure is then multiplied by your daily physical activity level
Mostly inactive or sedentary 1.2
Fairly active (walking and exercise 1-2 times a week) 1.3
Moderately active (exercise 2-3 times weekly) 1.4
Active (exercise hard more than 3 times weekly) 1.5
Very active (exercise hard daily) 1.7

This should give you a good estimate of the amount of calories you need to eat daily just to maintain your weight and is the energy used by your body to maintain essential processes. For those of us not cutting weight you can then break down your nutritional requirements as follows

Pre and Post training Nutrition
The timing and combinations of food we eat can have an impact on how we feel in training. If possible eat a good meal containing protein, carbohydrates (2.5g per kg body weight) and healthy fat 3 hours before training. You can also snacking on small carbohydtate snacks such as bananas and cereal bars 1-2 hours before training begins. After training there is a 2 hour period where depleated glycogen is replenished more rapidly so if possible you should manage to eat in this time. Aim for something with around 60-80g of carbs (more carbs the bigger you are) and 20-30g protein revovery has shown to be facilitated by combining a carbohydrate and protein snack. Many people shun carbs after training or late at night but for purposes of a speedy recovery make sure you manage to eat at least 1g per kg of body weight after an intense training session.

So what does all the training eventually prepare us for? In competition fights can last 5-10 minutes and to get to the finals you may have to fight as many as 10 matches in popular categories so you have short intense burts of activity separated with short breaks, highly taxing on the anaerobic and aerobic systems. Not something you would want to enter feeling any less than 100% energised. Sadly many people rely on crash diets and dehydration to cut weight leaving them feeling weak on the day of competition.

Cutting weight safely There are many studies detailing the use of extreme methods for cutting weight in martial arts athletes and I’m sure we’ve all made the mistake of trying to cut too much weight a week before competing.
Rapid weight loss and dehydration are know to adversely affect performance and can cause the following:

• Reduction in muscle strength and anaerobic power capacity
• Increased resting and sub-maximal heart rate
• Decreased cardiac stroke volume resulting in decreased ability to sustain work at a constant rate
• Lower oxygen consumption
• Impaired thermoregulatory processes
• Lower plasma and blood volume
• Depletion of muscle and possibly liver glycogen
• Difficulty of glucose homeostasis
• Altered hormonal status
• Reduced immune function

For those of you who have expericance these kind of sympotoms in competitions it is a sign that your body is not getting all the nutrients it requires.
Weight loss by achieving a negative energy balance is only one part of the equation. The foods we eat and the proportions in which we eat them are of equal importance and determine if weight loss is a result of losing fat mass, fat free mass or water via dehydration. Ideally when cutting weight we want to lose fat mass while retaining muscle as this results in better performance in weight class sports. To do this weight loss should be gradual and diet should be healthy and balanced.

Reducing calorie intake by 15% is enough to promote healthy weight loss

You can play around with percentages till you find something that works well for you but remember to eat enough carbohydrates to give you energy and aid recovery Usually 5-7g and enough protein to encourage maintenance of muscle mass 1-1.6g and aim to eat low fat products when ever possible whislt still including healthy essential fats.


BJJ is a physically demanding sport, it is important when training regularly to consume enough calories and eat a diet that is healthy and balenced.
Consider what times you go to training and ensure you eat a good meal 3 hours before giving you enough time to digest.
Post training recovery is facilitiated by comsuming a combination of carbohydrates and protein in a 3:1 ratio with 1g of carbohydrate per kg body weight.
Set realistic and safe weight cutting goals (for most people this is around 0.5kg a week)
This can be achieved by reducing your daily calorie intake by 10-20% and moderatley reducing carbohydrate and fat intake
Do not leave it all to the last week or rely solely on methods of dehydration!

Further reading on nutrtion
(this post was based on elements of sports nutrition that are supported by most mainstream research, I personally think we don't need to eat quite so much protein or use an abundance of supliments to excell in bjj) Talks about the importance of eating natuaral foods and not so much animal protein stesses the benefits of fruit and vegetables and setting goals for nutrition some easy simple guidlines Info on the evolutionary way of eating that is becoming more popular - more on this later :)

1 comment:


    Post work out smoothies :)