< Back to posts

Using Physiological Assessment to enhance training for Runners and Cyclists

Using Physiological Assessment to enhance training for Runners and Cyclists

SSC offer a variety of tests to assess various aspects of fitness, including functional movement screenings (FMS), biomechanical gait analysis, and physiological assessment. Our physiological assessments include either a long-graded exercise test (LGET) or a short-graded exercise test (SGET) paired with breath-by-breath gas analysis and/or lactate sampling. These tests are essential for cyclists and runners to identify accurately current levels of fitness and areas for improvement.
Both the LGET and SGET are types of Cardiopulmonary Exercise Tests (CPET) and give us several vital pieces of information for determining how to train to improve your endurance running or cycling performance.

Change in heart rate:

Heart Rate is the number of times the heart beats per minute. As the intensity of the exercise increases, heart rate also increases. This is to ensure blood is supplied plentifully to the working muscles to meet the increasing oxygen demands of the muscles for ATP re-synthesis. If an individual’s heart rate can stay low even as exercise intensity increases, it means that they still are able to deliver sufficient oxygen to the working muscles to meet the increasing demands. Therefore, they will be able to work for longer at higher intensities without a build-up of metabolic waste products.

Change in VO2:

Volume of Oxygen Consumed (VO2) refers to how much oxygen the body takes in per minute. During the CPET, the amount of oxygen consumed increases, as more is utilised by the working muscles. The slower the increase in VO2, the better the capability of the individual at getting oxygen from the environment to the working muscles. This allows the individual to work aerobically for longer and at higher intensities, meaning that there is less metabolic waste and that they are able to work harder before they begin to fatigue.

Lactate threshold:

Lactate threshold is the highest intensity the body can work at for an extended period of time without a large increase in lactate production/accumulation. When working below or on the lactate threshold, lactate is buffered at the same rate as production, preventing a build-up of lactate/H+ ions, allowing an athlete to continue to exercise. However, when working above lactate threshold, there is a sudden substantial increase in lactate production which increases above the rate of buffering/clearance – this leads to the accumulation of lactate and H+ ions. The resulting acidosis/acidification of the muscles has been linked as a limiting factor of exercise performance (Sahlin et al., 1976). Therefore, the higher the intensity of lactate threshold, the harder the athlete can work before acidosis occurs.

The benefits of performing a CPET and collecting this data is that it enables us to get an accurate understanding of an athlete’s current state of cardiovascular/pulmonary fitness and their suitability to participating in endurance events. The information also allows us to create a specific and accurate training programme designed to adapt and improve factors that may currently be limiting their performance. For example, by prescribing a specific heart rate or workload training zone, they may be able to dramatically alter their Respiratory Exchange Ratio (RER). Therefore, they start metabolising fat as their main fuel source during endurance events – providing much greater volumes of ATP (energy).

If you would like SSC services for physiological assessment or any information regarding this article please contact the team.


Sahlin, K., Harris, R.C., Nylind, B., & Hultman, E. (1976). Lactate content and pH in muscle samples obtained after dynamic exercise. Pflügers Archiv, 367(2), 143-149.