By John Kohnke
Once a greyhound has progressed in early training to gain strength and stamina, then the final phase of the race preparation to ensure speed will help ensure that the animal is ready to race. In previous articles, we have outlined a training program to achieve strength and stamina. Now let’s discuss the way to condition for acceleration and speed.
Training for speed involves muscular adaptations to increase muscle fibre size and the ratio of fast twitch fibres of high anaerobic capacity.
Metabolic adaptations include increasing the high energy muscle content of creatine phosphate for acceleration, anaerobic muscle enzymes and the efficiency of muscle buffering to reduce the accumulation of lactic acid and slow down the onset of fatigue at sprint speeds.
Initial Conditioning Training
In the last article, we discussed the early training program during the first 4 weeks to lay the foundations for strength and stamina, as these are important properties which will help ensure that the musculo-skeletal system can withstand the higher speed of racing. These processes take time to increase the strength of bones, joints and muscles over a 4-5 week period.
Other adaptations increase the blood flow to and within the muscles by improving cardio-vascular strength, the blood red cell count and overall delivery of oxygen to the contracting muscles. It is important that adequate bone strength is also gained to withstand the increased load bearing and centrifugal forces imposed by racing at speeds up to 70km/hour and when cornering at the gallop.
Natural Fitness
Greyhounds have been selected and bred over centuries for speed and agility, so that in contrast to horses, which require 12-16 weeks of conditioning and speed training, greyhounds are often ready to race within 4-6 weeks of starting a training preparation.
They have a naturally high ratio of fast twitch anaerobic fibres to aerobic fibres. Provided that the foundation adaptations for strength and stamina are achieved in the conditioning period, it may only take 10-14 days to adapt the already conditioned muscles to maximise contraction speed and endurance.
Many exercise physiologists involved in both human and horse conditioning consider that stamina, strength and speed are best illustrated as a triangle with strength and stamina as the base line, with speed at the apex of the triangle. In greyhounds, because they are naturally selected for speed, once off the lead in a free gallop, they quickly adapt the muscles to higher anaerobic capacity.
In a training program, we have to extend the speed endurance phase to enable the greyhound to gallop at maximal speed over the race distance. For race distances from 300 metre sprints to around 500 metre distances, anaerobic capacity must be dominant. In distance, ‘staying’ or endurance races from 500-700 metres, aerobic and anaerobic function must be adapted and balanced to allow the animal to maintain speed over distance.
Muscle Energy Stores
It has been well established that during the initial sprint stage of acceleration, greyhounds utilise high energy creatine phosphate as the primary acceleration energy source for the first few seconds of a race, switching to adenosine triphosphate (ATP) as the energy source released from the muscle sugar stores (glycogen) by the aerobic (ozygen using) and more dominant anaerobic (no oxygen) metabolic pathways to fuel muscle contraction during the remainder of the race.
Both the use of creatine phosphate and stored ATP in the initial acceleration period are essential because the demand for oxygen exceeds the ability of the cardio-vascular systems supply it to the rapidly contacting muscles.
The actual storage capacity of creatine phosphate and ATP in the muscles can be increased slightly by jump out training from the traps, but it is much more important to improve aerobic and anaeroic capacity and extend the periods of ‘oxygen debt’ in the contracting muscles so that they are able to produce sustainable levels of ATP over the race distance.
The diet must be adapted to provide adequate fat for aerobic utilization at slower training speeds to conserve muscle glycogen to extend its storage levels under race conditions. Fats do not contribute to muscle glycogen stores and are used aerobically as a“machinery” energy source for the diaphragm and gut muscles, so that maximum storage of muscle glycogen can be optimized for racing.
Although feed supplements of creatine phosphate and injectable ATP are popular, in scientific terms, they may act to trigger the release of their important high energy compounds, rather than actually increasing resting muscle storage levels.
Fast Twitch Fibres
Greyhounds have a naturally high proportion of fast twitch muscle fibres as compared to more sedentary breads of dog, making greyhounds, and their close relative, salukis and afghan hounds, the true “speed” machines of the canine world.
Training for speed involves the increase in size of the fast twitch, high glycolytic (glycogen using) fibres to help ensure that they can function for a longer duration at speed, and extending the aerobic, oxygen using fibres to their maximum efficiency so that the fast twitch anaerobic fibres can sustain speed under conditions of ‘oxygen debt’ towards the end of the race.
Many physiologists believe that the greyhound is unique in that it can be trained for specific race distances at maximal speed, and any increase in race distance, or interference in a race, where a greyhound has to accelerate mid race to catch the field, results in the rapid onset of anaerobic lactic acid and fatigue develops over a 50-75 metre distance.
Anaerobic Buffering
In all athletes, anaerobic lactate buffering capacity is an essential function that must adapted by speed training. Although this is a relatively rapid rate of adaptation where a combination of blood bicarbonate, blood proteins and lactate dehydrogenase enzyme activity are combined to ‘soak up’ and remove acidic lactic (hydrogen ions) compounds. A high buffering capacity helps delay the onset of fatigue, as well as damage to muscle cells by high lactate contractions produced by the onset of ‘oxygen debt’ in the rapidly contracting muscles.
The muscle concentration of the oxygen storage compound, myoglobin, also increases with training in general. Not only is it important to deliver the oxygen unloaded from the haemoglobin in red cells which passes through the cell walls into the muscle cells, it increases with training to even out the fluctuations in oxygen supply and provide as a store of oxygen in the final stages of a race under relative ‘oxygen debt’ in the rapidly contracting muscles.
The concentration and rapid response of myoglobin, which is produced within muscle cells and stored in well conditioned fit muscles, is dependent on the uptake of iron into the muscle cells. In my experience, boosting the intake of iron by 20mg daily of the last 2 days prior to racing, appears to ensure optimum myogloblin concentration for racing.
Speed Training
And lastly, speed training is achieved increasing the duration and speed of galloping over the selected race distance without risking premature fatigue or stressing the muscles unduly, so that they recover quickly after racing.
Whilst walking on a treadmill or lead, with an increase in gradient will help to adapt muscles for strength and stamina, speed is really only conditioned by sprints and all out-galloping. In human athletes, the term ‘power’ is used in conjunction with speed and strength, but the ‘power’ of muscle contraction is really dependant on controlled loading by gym and weight work.
Weight lifters condition the ‘power’ of muscle contraction and at the same time, muscle strength and bulk, but these muscles do not have a high speed of contraction.
The racing greyhound, even in contrast to human and horse athletes, must have speed without excessive bulk and ‘ballast’ of muscle development. It is a fine balance to achieve the strength and explosive “power” and speed during acceleration, but is really best conditioned by simple sprint ups, hand-slips and short distance acceleration to obtain the optimum efficiency from the jump out to the end of a race.
As mentioned above, speed conditioning to some degree, occurs in association with strength and stamina in racing greyhounds and in a much quicker timeframe. Commencing speed training from 4 weeks into a standard conditioning program, will allow these three important aspects of stamina, strength and speed to be conditioned.
Short distance sprints over 100-150 metres three times weekly for 10-14 days, followed by sprints on a race track over 300-400 metres once a week after 5-6 weeks of training, and then twice weekly, will help to improve fibre size, energy storage, buffering capacity and optimise speed and endurance over the race distance.
Racing a greyhound once or twice weekly will help to maintain muscle adaptations for speed and metabolic pathways, with minimal need to walk the greyhound between races to reduce the risk of tiring it, especially under warm summer conditions where dehydration is likely to develop.