Literature review

Cycling performance of cyclists and sprinters is greatly affected by the interaction of quite a number of variables such as environmental factors, human factors among other mechanical variables. In efforts to establish valuable variables through the development of essential power data on cycling activities. As power is essential in any other form of physical work, and cycling being an energy straining activities, sufficient power is need by cyclists for cycling. The essence of power required in cycling can be estimated and evaluated by ergometry. For cycling and bicycle ergometer and the magnitude of the external power and the entire workload are generally expressed in terms of watts. Maintaining and improving exercise performance among athletes is key and these two are achieved through constantly monitoring the workload. In cycling practices, the workload is often gauged through power output. However, the power output of cyclists depends on various parameters such as road gradient, topography, and riders’ specialties or experience. Therefore these factors also influence the critical power and workload.

Research has established that the power input originates from liberating metabolic source and the power output directly relates to metabolic processes of the body. In 2017, Tucker stated that power output is the rate of exchange of free energy as one of the valuable variables that contribute to the power data of cycling operations. The rate of increase of temperature and entropy is an equivalent product of the input metabolic power often generated from the meals that cyclists consume on a daily basis. To attain peak performance among cyclist, most of the cyclists have embraced the training with power. Coaches and physiologists have constantly highlighted the numerous benefits of training with the power firsthand among world champion cyclists. Hunter justifies the merits as he explains that even the cyclist power masters such as Phil Whiteman when had a try on the power meter. He discovered that his capability and cycling performance was tremendously improved over a short period as compared to other years of his training.

One of the advanced steps is the installation of power meters on bikes by cyclists to enhance the access of data while training or even during competition. Engineers and stakeholders have even developed power meter software to enable cyclists to truly accrue the benefits that come with the implementation of power meters in their training. However, at first, it was a huge challenge to accommodate seeing the projections of the graphs and statistics data from rides as it was daunting. But with time many came to embrace as merits were weighty than challenges and most importantly was the performance improvement on cyclists. The discovery of power meters was timely and was encouraged by the revelation that monitoring heart rate alone wasn’t enough indication on how to improve cycling performance.

Cycling Power output

Cyclists need to overcome various external forces and other factors that oppose the normal motion. Scholar Martin explains that based on physical and engineering principles it is important to identify them early enough to overcome resistance to produce movement. A simple definition of the power of the cyclist can be expressed in the form of,

P_NET = P_AT + P_RR + P_WB + P_PE + P_Ke

Where

P_NET =Power produced

P_AT = Needed Power to overcome aerodynamic

P_RR  = Needed Power to overcome rolling resistance

P_WB  = Power loss to wheel bearings

P_PE & P_Ke = Kinetic and potential energy

One of the greatest challenges to the movement that needs to be overcome in cycling is the aerodynamic drag force. Aerodynamic drag force depends on the cyclists’ frontal shape and bikes’ shape, density, and air velocity. The larger the frontal part the more the aerodynamic drag. The ground velocity of the ride and bicycle also causes a change in the air velocity to work against the ride. Other valuable parameters that affect the rating of the output power are difference in tire pressure, tread pattern on the tire, and the general weight of the bike and bike and texture of the gradient.

Muscle activities and cycling

Dorel and Hug (2015) showed that muscles generate a considerable amount of electrical signals as the muscles are activated during the cycling process. They further explained the importance of wire indwelling needles that applies surface EMG techniques and that deep muscles record signals of the extended area. Cadence and power are the known measure units for muscle performance during cycling, research and tests have shown that these two parameters extensively affects the muscle activities.

Critical power often referred to as asymptote for power and the work doable beyond CP are the main parameters that predict and give the tolerable duration of cycling exercise. The concept of critical power is used to integrate respiratory, physiological, and metabolic activities with a coherent framework to justify practical and scientific utilities. Other than these factors, other calibrating factors equivalently stimulate metabolic processes, some of these are setting exercise intensity relative to critical power, intramuscular response, and lactate threshold. Sports scientists and human physiologists have been working on developing the connection between mechanistic fatigue and exercise performance. However, fatigue is more of an ongoing and continuous dynamic process of an intense exercise involving peripheral and central mechanisms thus limiting the power of the neuromuscular systems.

Through hyperbolic evaluation of the cycling critical power and speed, duration illustrates how long a cyclist can maintain the motion above critical power. Studies showed that it is more often than the cyclists are capable to continue and maintain motion for as long as the intramuscular and metabolic processes can sustain the output power required to continue cycling. Hence there is no defined time limit set for cycling above critical power but rather depends on other parameters. Though there is no set time or duration limit for which cyclist can move above critical power, through review of past studies on the same subject, it can be established that an average individual (male cyclist) can sustain between 5 to 20 minutes while cycling above critical power while the average female can sustain between 2 to 15 minutes while cycling above critical power.