Doctoral thesis: New Sensor Technology Helps Measure Oxygen Changes in Muscles

Lihaste varustamine hapnikuga on töövõime oluline tegur. Siiani on seda olnud raske efektiivselt rakendada sportliku treeningu või taastava ravi eesmärgil, kuna olemasolevad mõõtmismeetodid on olnud kaudsed või ebamugavad kasutada. Karmen Reinpõld uuris oma doktoritöös uue sensortehnoloogia kasutamist, mis mõõdab hapniku muutusi lihases otse naha pinnalt, ja testiti seda erinevate füüsiliste koormuste tingimustes.

Understanding how muscles are oxygenated can help improve athletic performance and aid in rehabilitation, but traditional measurement technologies are inconvenient to use. However, a novel sensor technology enables muscle oxygen saturation to be measured from the skin. In her doctoral thesis, Karmen Reinpõld, PhD candidate at the School of Natural Sciences and Health, Tallinn University, investigated the application of this technology in sports science in both elite and amateur athletes.

Muscle oxygen saturation is a key factor in performance. However, so far it has been difficult to effectively apply in athletic training or rehabilitation due to the indirect or inconvenient nature of the existing technologies. Reinpõld's doctoral thesis investigated the use of new sensor technology that measures oxygen changes in muscle directly from the skin’s surface. The technology was tested under various levels of physical exertion.

In addition to the use of the technology, a notable aspect of the thesis is that it investigated elite and amateur athletes with significant training experience and high exertion tolerance. Such experiments are typically carried out with students and volunteers, whose physical fitness and motivation levels are varied. This makes the findings of this thesis particularly valuable for trainers and sports scientists who are developing effective training programmes and research methods.

The research showed that during physical exertion, muscle oxygen consumption differs significantly from whole-body oxygen consumption. These findings provide deeper insight into how respiration and blood circulation respond to muscle exertion over time and under varying intensity levels. Additionally, data analysis allowed an assessment of the differences in muscle activity and oxygen consumption in load-bearing muscles between the dominant and nondominant leg. A slight asymmetry in exertion between two sides of the body is a natural way to maintain the internal balance needed to survive in an ever-changing environment. However, training or injuries may cause unhealthy imbalances. The findings of the current study can help prevent these imbalances.

The research also highlighted differences between participants with varying speed or endurance potential. This information is useful for tailoring training loads, since muscles may respond in different ways. The new sensor technology provides an effective way to measure and account for these differences in training.

Karmen Reinpõld, PhD candidate at the School of Health and Natural Sciences, Tallinn University, defended her doctoral thesis "Bilateral Measurement of Oxygen Saturation in the Vastus Lateralis Muscle During Endurance and Sprint Cycling in Well-Trained Cyclists Across Different Age Groups: Associations with Systemic Reactions and Performance Metrics" on 20 December. Her supervisors were Associate Professor Indrek Rannama and Professor Kristjan Port from Tallinn University. The opponents were Professor Vahur Ööpik from the University of Tartu and Professor Peter Hofmann from the University of Graz.