Tag Archives: Oxidative system

Fat loss for athletes!

Body composition and body mass are important for most sports. The success of an athlete can rely heavily on falling within the norms of their sports, especially where a weight category is involved. Nutrition and training are both vital in the role body composition and weight management. I will not discuss dietary strategy as it is not my are of expertise. Instead I will discuss the training considerations and strategy.

Step one is for an athlete to identify whether he needs to reduce bodymass (weight) or reduce body fat. Bodymass deals directly with bodyweight on the weighing scale with no concern for body composition. Body fat deals with body composition with possibly no influence on overall bodymass. When reducing body mass the main focus, is to create a consistent calorie deficit. How one trains doesn’t really matter as bodymass will decrease over time if calorie expenditure exceeds consumption. The issue is that this reduction will not be selective in terms of tissue loss. Both muscle and fat tissue will be lost but this is not such a good thing. In many cases an athlete will need to retain as much lean mass as possible and may even need to increase or at least maintain it. This creates a more complicated scenario where fat tissue must be the focus for reduction while avoiding any muscle tissue loss. The training strategy becomes a little more complex.

We know that in terms of metabolism, exercise at lower intensities utilise fat as fuel more effectively than high intensity exercise. The main drawback is that in terms of time efficiency it takes a relatively long period to burn sufficient calories. The other issue is that low intensity work can promote adaptations that are not so favourable for an athlete. Long periods of low intensity (LSD) training can promote a conversion of type 2 muscle fibers into fibres which more resemble the characteristics of type 1 muscle fibers. The athlete runs the risk of losing strength, speed and power. So this method must be used sparingly.

High intensity training has been touted as the magic pill for fat loss and performance in recent literature. Calorie expenditure is higher for a given work period and metabolism is elevated in the post training period. Sessions must, however be shorter as they will be more demanding. It is in this post training period where an elevated metabolism and active oxidative system plays its role in metabolising fatty acids. HIT may also promote strength, power and conditioning through a number of adaptive responses. At first glance this seems to be the obvious choice. As with most training methods it carries its disadvantages. By focusing on HIT we become reliant on the Glycolytic system during exercise. This system utilises carbohydrate metabolism and is always active even at rest when the oxidative system is dominant. Over time an athlete may promote the use of carbohydrates during metabolism which will in fact spare fat cells. If they do not consume enough carbohydrates there can also be a reduction in lean tissue as muscle cells do not get enough energy to survive.

The best strategy is to utilise both methods in an appropriate fashion. LSD can be made more effective in reducing fat and improving fat oxidisation by adding fasted LSD sessions into a program. Done before breakfast or immediately following a training session, enzymes active in fat oxidation must up-regulate to compensate for glycogen depletion. This means that less time is needed to initiate fat oxidation. HIT should then be performed in a fuelled state in a separate session to make use of its benefits. When both types of sessions are used in a balanced way that does not impede the athletes recovery, they can see all the benefits while negating the disadvantages.

As with most strategies a balance is required for optimum results. The body is exceptional at adapting to stress. Overemphasising one method over another will only display short lived success and may create problems in the long run. In the case of managing body weight and body mass a strategy must be formulated to suit the needs of the individual. A gradual and monitored approach is best for achieving long term and consistent results.