FUEL YOUR RACE
Nutritionist Nigel Mitchell explains how to lose weight without compromising training
Reach your race weight without compromising your training.
Weight management is a topic that competitive endurance athletes love to discuss. The issue, though, is how do you reduce your calorific intake enough to lose weight but ensure you have adequate energy for training?
In endurance sport, carrying extra weight slows you down. On the bike when climbing on a six per cent climb, 1kg is equivalent to having to produce about an extra six watts of power.
To understand this we need to examine and challenge some of the basic principles of nutrition. In very simple terms, the body stores all extra energy in the form of adipose (fat). We store a small amount of energy in carbohydrate, in the region of 60g, in the liver and a few hundred grams in lean tissue. Even in a lean person, the body will store about 10kg of fat and the reason we stock all of this excess energy as fat is because fat yields more energy than any other organic nutrient.
One gram of carbohydrate provides 3.75kcal and 1g of fat provides approximately 9kcal per gram. Body fat (adipose) is not pure fat, so 1g of adipose is around 7kcal. That means 1kg of adipose is worth about 7000 kcal. Therefore, to lose 1kg of body fat, you need to be in an energy deficit of 7000 kcal. In exercise terms, that’s the equivalent to someone running about
70 miles, or in food terms this equates to about 28 Big Macs or about 6.5 kg of cooked quinoa.
When we train, we use more carbohydrates, and if we do not have them in our system, it will affect the quality of training; we have all under-fuelled and felt the results of ‘bonking’.
One other point we must consider is that when we are losing weight, we want to lose fat, not muscle but, all too often, when we reduce energy intake we lose both fat and muscle. There are many reasons for this but one major reason is when we reduce energy, especially from carbohydrate, the body will use more protein as an energy source. However, there are both dietary and exercise strategies that can help reduce and prevent the loss of muscle.
Before starting a weightloss plan, people should consider whether it is worth the additional work and stress. Also, how much weight have you got to lose? Today there are many body composition monitoring devices, such as scales, that use bio impedance to gauge body composition. The precision of these can be variable, but they can provide a guide for weight loss and also the monitoring of weight loss.
KEY POINTS FOR EFFECTIVE WEIGHT MANAGEMENT »
Following a weightreducing diet can add additional stress to the body. Only start this if you have good health. Have your iron levels checked and, if low, consider an iron supplement too.
Plan gradual weight loss. This will compromise training and recovery less than rapid weight loss. 0.5-1kg a week is about the maximum you should aim for; this equates to a deficit of 500-1000 kcal per day.
Ensure you have about 1.5-2g of protein per kg of body mass a day. This should be split up throughout the meals, eg, a 70kg triathlete would require 100-140g of protein a day. Dairy protein is good, and there are plenty of good vegetarian sources of protein. Foods, such as quinoa, soya, pulses and nuts, are excellent.
Periodise your carbohydrate intake. If you are doing light or low-intensity training, reduce the carbohydrate around the training session. If, the next day, you have a hard session, then the carbohydrate should be increased after training.
Base your carbohydrates mainly on low glycemic index (GI) foods such as porridge, sweet potatoes and quinoa. These are more slowly absorbed.
Include a mid-morning and mid-afternoon snack – banana or about 40g of pistachio nuts work well. A common mistake is for people to cut fat back too far. Like proteins, we need essential fats as well. I always recommend that people include fats ,such as oily fish, eggs, avocado, milled seeds, pistachio nuts, olive oil. Iʼd suggest an omega-three supplement high in Eicosapentanoic acid (EPA), aiming for about 1-2g a day. Also, with elite athletes, I may include a CLA supplement as well.
Monitor your weight. Try to get weighed on the same scales at the same time each week, and keep a record of this to spot trends.
Incorporate some strength work to help reduce muscle loss.
For most triathletes, weight management should not be a big issue, and for anyone who is really unsure they would benefit from some professional dietary input. The SENR register provides a list of suitable qualified sports nutritionists (senr.org.uk/ find-an-senr-nutritionist)