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Recent decades have witnessed a remarkable expansion of the application of scientific principles to sports and exercise. Whether running a marathon, competing in a triathlon, or cycling in a road race, all activities require focus, exertion, energy, and discipline. Some endurance athletes methodically follow their training program while other athletes leave training to chance. They pick and choose their workouts without monitoring if they are effectively training both their aerobic and anaerobic systems. This method may work for a small percentage of athletes, but the latter typically arrives at the start line under or over-trained. To effectively train for an endurance race, or coach an athlete who is competing in one, accurate physiological data is paramount to guide and monitor training performance and intensity.
What is included in physiological data?
For endurance athletes, the aerobic threshold and anaerobic threshold is at the root of physiological data. All activity is fueled by the energy consumed from food. During rest and less intense bouts of exercise like distance running or cycling, the aerobic energy system works to produce adenosine triphosphate (ATP), the body’s source for energy (Ghosh, 2004). The aerobic energy system breaks down either fat or carbohydrate to make ATP.
When activity levels increase, the body increases its use of the anaerobic energy system, which uses carbohydrates (namely glucose and glycogen) stored in muscles (Park & Kwak, 2016). The anaerobic energy system operates by using glycogen and lactate as fuel for intense activity. There are two energy systems that fall into the anaerobic energy system; immediate (uses ATP and Creatine Phosphate) and short-term (which uses glucose as a source of energy. Both anaerobic systems do not require oxygen. The anaerobic energy system is associated with an athlete’s sprint to the finish line or during a kick to get out of the transition area in triathlon.
How can understanding the physiological systems affect performance?
Physiologically, there are three ways an endurance athlete can increase performance: increase aerobic capacity, elevate lactate threshold, and improve movement economy. An athlete can increase their aerobic capacity by knowing, and training at their individual aerobic threshold. The aerobic threshold is an essential marker of intensity for endurance athletes. It corresponds to the most critical training zone to use in developing aerobic capacity, the key to all endurance activities that last more than 2–4 minutes. When an athlete improves their aerobic capacity their body is able to effectively use fat as a fuel source and increase the energy stored in the muscle. In essence, the athlete can go further and longer on their available fuel.
The anaerobic threshold (also referred to as the lactate threshold) defines the upper limit of sustainable efforts in training and competition (Ghosh, 2004). Athletes most frequently attribute the intense burning felt during exhaustive sessions of exercise to the accumulation of lactate in the blood, where in fact it is caused by the byproducts associated with excess lactate production. For endurance athletes, this is the area where gains in speed are made.
Movement economy is a complex concept that signifies the sum of various metabolic, cardiorespiratory, biomechanical and neuromuscular characteristics during submaximal exercise (Barnes & Kilding, 2015). Many of the determining factors of movement economy can be adapted through training or other interventions, however, a change in the economy of one athlete may not work with another athlete because of differences in other physiological or biomechanical characteristics (Barnes & Kilding, 2015). For each endurance event, sport-specific movement economy differs and for triathletes, factors differ from one discipline to another.
To effectively train for an endurance race, or coach an athlete who is competing in one, accurate physiological data is paramount to guide and monitor training performance and intensity. Gains in aerobic capacity and elevating one's lactate threshold can markedly improve performance for the athletes and equate to success on race day.