SPECIALISED TRAINING Continued from Mrs. Williams p

MEASURING THE INTENSITY OF TRAINING Elite athletes need to know that they are training at the right intensity. The training needs to be intense enough so that it is beneficial, but they have to be careful not to cause any long term damage by pushing themselves too hard. If we need to be scientific about training, how can we measure how hard athletes are working without using complicated laboratory equipment?

SIMPLISTIC MEASURES OF TRAINING INTENSITY Using the BORG SCALE Measurements are subjective as they depend on the performer’s perception of how hard they are working Measuring heart rate during performance Slightly more reliable Can be affected by other influences e.g arousal, temperature

LACTATE SAMPLING The development of suitable devices for lactate sampling has enabled this method to become more popular. Involves taking a minute sample of the performer’s blood. Within a few seconds, the hand held machine analyses the sample and gives a readout of the amount of lactate present.

WHAT DOES IT TELL US? If lactate levels rise during training it is because anaerobic glycolosis is occurring in the exercising muscles and this is becoming the main method of resynthesising ATP. Performers need to train at levels of oxygen consumption (and therefore different intensity levels) that are above their lactate threshold. The higher the reading of lactate in the blood, the higher the intensity of the workout. Through experience and knowledge of lactate levels in their performer(s), a coach will know how hard a performer is working.

WHY DO WE USE IT? All concerned with a performers lactate threshold. This is taken to be a 2 mmol increase in lactate per litre of blood above resting levels. OBLA is taken to be a 4 mmol increase in lactate per litre Lactate threshold is linked to VO2 max. The higher the % of VO2 max, or the higher pace at where the lactate threshold takes place, the fitter the athlete.

WHO USES IT? Not easy for games players as the body needs to be relatively stationary Commonly used by rowers, cyclists and runners who are exercising on stationary machines. Can be used by swimmers who take very short breaks in between sets.

THE RESPIRATORY EXCHANGE RATIO (RER) This is the ratio of carbon dioxide released by the body to the volume of oxygen consumed (VCO2 / VO2) It can be used to estimate the relative contributions of fat and carbohydrate to the provision of energy for ATP resynthesis. RER works as an indicator of fat and carbohydrate breakdown, because fat and carbohydrate differ in terms of the amount of oxygen used and carbon dioxide produced during oxidation. Remember that fat oxidation requires much more oxygen than carbohydrate matabolism.

WHAT DOES IT TELL US? When fat is the major fuel, the amount of oxygen consumed will tend to be a big number, which will make VC)2 / V2 and hence RER a small number. The amount of oxygen being consumed will be a more modest number when carbohydrate is the main fuel, and therefore VCO2/VO2 and RER will be bigger since less oxygen is required to break down carbohydrates than is needed to break down fat.

HOW IS IT MEASURED? Measurement of VCO2/VO2 is completed using a cycle ergometer or treadmill, with the athlete attached to a gas analyser. Volumes of carbon dioxide being produced and oxygen being consumed are measured directly.

WHAT DO THE VALUES SHOW? When RER is measured at about 0.70, 100% of energy for exercise is coming from fat. When RER settles at 1.00, carbohydrate is almost the sole source of fuel. When RER is 0.85, metabolism is equally divided between fat and carbohydrates. RER MEASURED DURING EXERCISE CAN TELL ATHLETES AND PHYSIOLOGISTS WHERE THEY ARE IN REGARD TO FUEL USAGE.

WHY WOULD THIS BENEFIT ATHLETES? Endurance type training improves the ability of the muscles to use fat as an energy source, but using fat is also a sign of aerobic work. Many elite performers depend on anaerobic processes to provide energy for their event. Fat is not used as an anaerobic energy source. By knowing the RER at which the performer is exercising, coaches can see whether they are working aerobically or anaerobically.

BASICALLYYYYYYYY…… RER LESS THAN 1.00 = some fat being used therefore SOME aerobic work. RER MORE THAN 1.00 = energy is being provided solely by anaerobic means. In other words, RER becomes another way of measuring INTENSITY. Very limited method of testing because of the need for expensive laboratory equipment and restricted to rowers, cyclists and runners as they HAVE to use the equipment.