Nuffield Research Placements 2019

Exploring the physiological responses that occur throughout and after maximal incremental exercise tests and during triathlon racing

by: Billy Stanhope

The main aim of this study is an exploration of the physiological changes that occur throughout maximal, incremental exercise tests and during a lab simulated triathlon race, such as; muscle oxygenation, heart rate, VO2 and blood lactate. These results will be used to support physiological reactions throughout the body such as; aerobic and anaerobic respiration. This data will also be used to help athletes make their training more specific to what they need to train and improve upon. If the data collected correlates with the physiological processes in the body then the main aim of the experiment will be met or not.

The key objectives of this study is to:

1. Plan a method of how the data is going to be collected and practice this method until it is fully understood
2. Identifying suitable participants in triathletes
3. Performing the research and gathering sufficient data
4. Analyse the data collected
5. Come to a conclusion on the data to see whether is supports current theories and physiological processes

This data collected can be used to support or lead to new hypotheses on physiological processes in the body. This data will also help triathletes in their races to test physiological limits and  improve their training by making it much more specific to their needed improvements both physically and tactically. When all the data is collected it will be analysed by using statistics and comparing the data from multiple athletes on their visits to Essex university.

During the first two weeks of my placement I was learning the basics of the study and practicing the method that was going to be implemented, the blood lactate would come from anaerobic exercise and would rise the more difficult the maximal tests became, meanwhile NIRS tracked heamoglobin and oxyheamoglobin levels. After learning the basics of the study we then began to practice the method such as learning where to position the NIRS devices on the athletes body and recording the results during the maximal tests and self paced triathlon.

Triathletes will have three visits to the laboratory, the first visit is the incremental maximal test on the treadmill after this the triathlete will be familiarised on the swimbench and woodway, each athlete will also be weighed and their height measured so that the program for the bike incremental maximal in their second visit is prepared and programmed. The last incremental maximal test is the swimbench which the pace will be determined by the familiarisation in the first visit. On the final and third visit the triathlete will perform a self paced triathlon.

While at Essex university I made sure to use some of the high rage equipment in their possession such as; NIRS, Large Treadmill, blood lab and many other pieces of equipment for the study. To help me with the study I worked alongside a university student who helped me work out the method and help me achieve an understanding of the study while I helped him with the collection of data during the athletes visits. A lecturer at the university also helped us by showing us the method of setting up the NIRS device to any laptop.

Muscle oxygenation is measured by using NIRS (Near Infrared Spectroscopy), NIRS devices use the electromagnetic spectrum (from 800 to 2500 nm) (1), the results are analysed by the absorption or reflection of the electromagnetic waves as deoxygenated haemoglobin and oxygenated haemoglobin have different absorption spectra meaning infrared waves are absorbed at different frequencies(2).

Triathletes will perform three incremental maximal tests which will be on a swim bench, bike and treadmill, NIRS devices will be attached to their latissimus dorsi (back muscle) and vastus lateralis, which is one of the 4 main muscles in the quarecip(3). Certain muscles are used to reveal how the muscles work and how hard the muscle group would be working such as; when the athlete is on the swim bench the latissimus dorsi will be working and it’s evident in the muscle oxygenation. To gather more accurate results after the first maximal test on the treadmill there is a familiarisation on the woodway for the triathlon and the swim bench so that the pace for the maximal test can be accurate.

The method used in the maximal test was:

1.The NIRS devices would be attached to their latissimus dorsi and vastus lateralis.

2.After this resting oxygen saturation would be taken and on the NIRS reading a marker would show this

3. An oxygen mask is attached to the triathlete and begins to record oxygen and carbon dioxide levels

4.The triathlete would first warm up on either the treadmill or bike and swimming bench, a marker on the NIRS readings would show this

5. After the warm up the triathlete would either begin the treadmill maximal test or bike and swim bench maximal tests

6. On the treadmill there are incremental stages of difficulty increasing every 3 minutes

7. Every 3 minutes there is a 30 second rest stage in which blood lactate is recorded and a marker is put down on the NIRS reading and all oxygen levels are recorded

8.On the bike and swim bench maximal test there is no rest other than the swim bench which is a short rest to record blood lactate.

9. Each stage is shown by a marker on the NIRS readings

The method used in the triathlon test was:

1.The NIRS devices would be attached to their latissimus dorsi and vastus lateralis.

2.After this resting oxygen saturation would be taken and on the NIRS reading a marker would show this

3. An oxygen mask is attached to the triathlete and begins to record oxygen and carbon dioxide levels

4.The triathlete would first warm up on either the treadmill, bike or swimming bench, a marker on the NIRS readings would show this

5.After the warm up the athlete will begin the 10km bike ride

6.After the bike ride there is a short 30 rest rest period for the change over to the swim bench for a 750m swim

7.After the swim bench there is another short 30 second rest period for the 5km run on the treadmill

8.The NIRS readings will show markers to show the change between stages of the triathlon

Conclusion

Overall two athletes were tested on the run test. The NIRS readings show that the oxygen saturation of their latissimus dorsi stays fairly constant throughout the run unlike the vastus lateralis which has oxygen saturation variation throughout the test as the muscle is being used more this causes the muscle to respire and lower the amount of oxygen present in the leg. As time went on exhalation of CO₂ and O₂ increased, this is because the body is not able to process the oxygen it inhales fast enough to be able to use it effectively as the athlete begins to hyperventilate. When the test continued to the later stages heart rate is constantly increasing, however there were a few technical problems with the equipment so some values of the heart rate were not recorded. Overall these results support the physiological reactions that occur throughout the body, along with that the results can be used to help athletes train certain areas and make their training more specific to what they need so they can improve their performance.

More research would need to be done with multiple athletes so that the results can be assessed statistically to prove that the results are reliable, as sadly only two athletes were tested in the run test meaning that they would still need to complete both the bike and swim test along with the triathlon simulation. This would need to be done with multiple athletes as well to secure accurate results.

1 - https://www.eurofins.co.uk/agro/feed-forage/nirs-analysis/what-is-nirs/ - 21/07/2019

2 - https://www.shimadzu.eu.com/about-nirs-principle-operation-and-how-it-works - 21/07/2019

3 - https://www.healthline.com/human-body-maps/quadriceps#1 - 22/07/2019