Tuesday, August 14, 2012

Ergogenics.. Improving race day performance

By definition it is the tendency to increase work output. Nutrition is a prime example. Consume carbohydrate during prolonged exercise and you can exercise for longer, plain and simple. The mechanism behind the ergogenic effect of carbohydrate ingestion is two fold. Firstly it provides a fuel source for contracting skeletal muscle. However, secondly and of a more complex and less understood nature it staves off the fatigue signals monitored by the brain.

Here we now have two vastly different components that we can target with a little physiological knowhow. i) a peripheral mechanism; being the muscle its-self and the metabolic complexity that is required for continued muscle contraction. ii) the central component; The brain and nervous system that monitors the energy status of the body and ultimately regulates intensity and duration of exercise based upon feedback from the periphery.

Nutritional ergogenic aids can be classified into two main categories. Ones that targets the periphery such as sodium bi-carbonate, nitrates and also fuel substrates such as carbohydrate. These aids all help sustain muscle contraction by either supplying a fuel source, maintaining homeostasis such as pH levels or by assisting biochemical reactions that result in a greater yield of energy production for muscle contraction.

In contrast we have the aids that work on the central component, these being the ever so common stimulants such as caffeine. The central nervous system is what drives the muscles and if we can ‘turn up the dial’ of the output from the brain then the muscle will respond and contract with greater force. Central stimulants weather they be natural or synthetic are simply mimetics that act very similarly to the bodies own hormones. If you stimulate the nervous system the neural drive to the muscles is increased, the cardiovascular system pumps more blood and the body is better equipped to deal with a life threating situation. After all, this ‘flight or fright’ response initially evolved so we could escape danger back in our early years of evolution. Fortunately for athletes enhancing sporting performance works along similar lines. Perhaps adding a little danger to our next race may help crack a few new PB’s?

The power of this up regulation of the central nervous system on human performance is probably best outlined by the old wives’ tale of a mother lifting a car off her child. A super human effort that may be beyond belief but if indeed true may just outline the actual limits of human performance under the right circumstances.

Science has shown that central stimulants can improve performance in a range of events and can be as effective as eliciting a ~1-12% improvement in performance. Notably however is the large inter-individual variation in this performance improvement. Some respond well and others don’t.. so trying your chosen strategy prior to race day is essential. Preferably under controlled conditions so you can monitor any performance improvements.

My latest research project was based on the premise that we can improve performance using ergogenic aids. But more precisely what happens if we combine an ergogenic aid that targets the peripheral mechanisms with one that targets the central component? Theoretically we should get a combined effect. For example consuming dietary nitrate in the form of beetroot juice has now been repeatedly shown to improve time trial performance. It exerts its effects on the muscle itself by increasing blood flow and somehow reducing the oxygen cost of muscle contraction thus, increasing gross efficiency. It has been shown to improve power output during a 10-16km TT performance on average by 3-6%. Then we have good old caffeine that works via a central mechanism. It’s tried and tested and capable of improving performance to a similar degree as beetroot juice. So in theory we could see a 6-12% improvement in cycling performance? Well we tried this and I wont disclose the results just yet, that’s another story.

One more interesting observation that has been tested in the laboratory and proven to work is the use of music to enhance performance. These days its common to see pros warming up listing to what ever it is that gets them pumped up. But what is this pumped up mechanism and how does it work? Once again its simply a central stimulant. The brain in all its complexity sends commands to the muscle. If we can ‘make the brain happy’ by activating reward centres that are integrated with the motor cortex that drives the muscles then we can drive the muscles harder. Ultimately it’s like having a more powerful battery driving the engine.

So where does peak performance lay? Once we have adapted to training and prepared our physiology for optimal performance we must then ensure our race day protocol maximises our physiologies full potential. Optimisation of the performance of the central component through motivation, and the possible use of centrally acting ergogenic aids is step one. Then, giving the muscle every chance of functioning to its full potential by making sure it has adequate fuel for contraction and the biochemical capacity to contract as efficiently as possible while maintaining homeostatic balance.

Now.. get out there, there is a race to be won…

Tuesday, January 31, 2012

Well rounded cyclist or master of the art?

We are quickly approaching the beginning of the road season and hopefully full of inspiration and motivation from all the action of both the Australian National events and the Tour Down Under. The start of the year is often the best time to reflect on the year gone and begin to map out the year to come. I have a few athletes that have given me their goals for the year and we are now beginning to decide the best course of action to achieve these goals as the year progresses.  I try to follow the old premise ‘practice what you preach’ but often find myself training without any specific direction and following old habits. This year I’ve set my first goal to change this and follow a structured program that addresses all the weakness I have in my cycling armour.

Before I go any further I’ll say that I don’t have weak points and any race that I loose is sheer bad luck!!!.... Any good periodised program consists of several key stages which most would be familiar with. Each phase has a specific goal and we incorporate specific sessions/races that will target the physiological/psychological adaptations that we desire.  The basic premise of any program should be this; Step 1: Teach the body to use oxygen, spare carbohydrate and develop endurance to go the distance. Step 2: Teach the muscle to resynthesise energy quickly via the appropriate energy systems, clear waste products, maintain chemical homeostasis and activate all muscle fibres (neural recruitment and patterns). Step 3: Get specific and determine the physiological demands of the races you wish to excel in. Specificity of training is often the most overlooked of all components. Think about.. How long are the efforts required to go with breaks, how many watts do I need to put out in a sprint, can I repeatedly attack and recover to make sure I can go with the important moves in a race?

A well rounded rider may be good at all of these components. More importantly you cannot expect to master all of them in one season. It may be better to stick to one component and focus on it. I have worked with a few guys now that have specific goals and forego the want to be the ‘all-rounder’.  If you want to be good at time trails then hang up the road bike and perform the majority of your training on a TT bike. Stop riding 100+km and focus on going as fast as you can for shorter distances. This would require dedication to interval training and a lot of time focusing on holding power in the most aerodynamically position possible. Once you have maximised your ability to use oxygen (aerobic capacity) you need to work on improving your aerobic threshold. In untrained individuals power at lactate threshold may occur as low as 70% of their peak power and elite athlete with some threshold training may increase this to 80-82.5%. With specific training I have seen individuals increase this to up to around 95% of their peak power but this has taken years of specific threshold training and the ability to hurt like nothing else.

 Alternatively, If you want to be a sprinter then be specific and perform more sprints. This gets a little trickier because you still have to be there and in a good position when the hammer goes down so there are skill components to think about. Sprint training is all about energy turn over. The more energy you can produce the faster you will go. Learning to do this defies the normal physics of endurance training and turns more to all out strength. Ever heard of the mother that can lift a car to save her baby? Under normal circumstances we are unable to activate our entire muscle, we can however learn to do this by maximally loading the muscle and nervous system through either low repetition high load resistance training or through specific all out efforts on the bike. Then comes learning to sustain near maximal power for the entire length of a sprint. Generally speaking we measure anaerobic capacity through a Wingate test which is essentially a 30 second all out sprint. We record time to maximal power, average power and the degree of fatigue throughout the 30 seconds. All of these components will determine the type of sprinter you are.

If you are more inclined to go up hill then training specifically to go up hill is required. Body mass now plays a large role and power to weight ratio expressed as Watts/kg.bodymass is the main predictor of performance.  A good club level climber has a peak power (power at VO2max) of about 6 Watts/kg and a threshold power of around 5.2 W/kg. This may be good enough to hold a few Strava KOM’s but the Pros are pushing sustainable numbers closer to 7 W/kg.BM. Climbing is not all about power to weight it is also about learning to accelerate above threshold and recover again… repeatedly!! I prescribe a lot of out of the saddle climbing for my athletes that  want to improve their climbing skills. This teaches them to recruit different muscles which is a major benefit and can dramatically improve climbing ability.  And of course what goes up must come down so learning to descend quickly and safely is essential.

To achieve goals you need to identify the specific demands of the activity and determine the best techniques to target both the skills needed and the physiological components required. Sometimes it is just the motivation in training to learn to hurt like you would in a race. Training with friends is often a good way to include a little extra motivation to push harder and the best way to improve skills if specific race type scenarios are practiced. So… Get out there and train properly. Map it out, monitor progress ensure adequate recovery and most importantly RACE HARD!!