Artinis Literature Overview 2019 - Exercise physiology
They
/ðeɪ/
With this pronoun chosen as word of 2019 [1], inclusivity can be considered a very influential phenomenon in today’s literature. From a classical perspective, we at Artinis separate the publications into the domain of functional brain monitoring and muscle research. ‘Brain’ - and ‘Sports’ people. With more exercise physiologists shifting towards an inclusive, integrated cerebral solution, the gap with neurology becomes smaller. Without the intention to offend or exclude any NIRS researchers, but also aiming this blogpost at the devoted crowd, we browsed through 2019’s literature shelves. This review will highlight a handful of publications in the domain of movement science.
Walking
Walking is natural for most, but it requires significant coordination and especially for our younger readers, practice. Add certain disturbances in the environment and the cognition aspect controlling for locomotor tasks becomes highly involved. Age effects, diseases and the influence of secondary tasks such as talking or mental calculation, have been nicely reviewed by Pellicioni et al. (2019) [2]. A total of 35 papers (only three before 2010) written in well-established journals has been included in this review. The paper gives accessible access for a systematic understanding of the following three domains; brain activation changes during complex walking, brain activation patterns in healthy young people and brain functioning in neurologically/walking impaired clinical groups. The conveniently accessible prefrontal cortex has been analyzed during stationary walks on a treadmill with the OxyMon system but also during ‘real world’ walking tests with the fully wearable PortaLite [3]. There appears to be a relation between activation of the prefrontal cortex and type of complex walk, 60 % of the included comparisons reported a higher activation for the complex walk types compared to ‘regular’ walking in healthy younger and older adults. More than 80% of the included studies’ comparisons showed the same increased activation for clinical groups with balance disorders. We are looking very much forward to see what future studies might find during the maturational milestone ‘a baby’s first steps’.
Swimming
Swimming comes natural to some, but for this next project the researchers collaborated with one of the best divers in the world, the seal. New light has been shed on the cerebral oxygenation during deep dives by McKnight et al. (2019) [4] who included wearable NIRS to measure the responses in brain oxygenation during deep dives. If this sparkled your interest we highly recommend reading our earlier blogpost covering this very wet lab.
Sprinting
Sprinting is one of the key parameters when it comes to quantifying fitness. Although sprint tests with highly trained jiu-jitsu fighters might sound a bit abstract, there is no discussion needed whether a match will be won by the most effective player. With movement intensity being one of the key-parameters ineffective fighting, the high-level fighters are generally very good in repeated near-maximal exercises. Woorons et al. (2019) [5] analyzed ten fighters sprinting back and forth on the tatami during two sessions, the first after breathing normal and the second session after voluntary hypoventilation at low long volume. Besides the cerebral oxygenation measured with the PortaLite system, muscle oxygenation was measured with a PortaMon device on the lower third of the right vastus lateralis. The performance was similar for the two sessions and there were no reported changes in muscle oxygenation related to hypoventilation. They did, however, observe a significant increase in change in deoxygenated hemoglobin and a decrease in the difference between oxy- and deoxyhemoglobin. Since performance is not altered, the researchers suggest this might be due to a higher oxygen uptake following the recovery periods. The aim for future studies is distinguishing the best conditions for repeated sprint training, and describing the physiological adaptations occurring over a longer period of time.
Trail running
Trail running is an endurance-based activity on the other end of the fitness spectrum. With battery life up to eight hours and offline data collection possibilities on the standard modalities, continuously measuring ultra-endurance races become possible with Artinis’ systems. Even though they were not limited by equipment, Giovanelli et al (2019) [6] stuck to a pre-, post-test regimen. The research group evaluated the muscle oxidative function during an uphill test and incremental test before and after a running competition. Not just any running competition, a 32 or 50 km long-running competition. Initially, thirty-two subjects enrolled in the study, but only eighteen finished the race and post-test regimen. The PortaLite was used to measure micromolar changes in (de-)oxygenated hemoglobin and myoglobin. These values were normalized to the values of maximum muscle deoxygenation obtained during transient ischemia, a procedure known as a physiological calibration. Peak power and time decreased in post-race testing but also at the same workload a decreased oxygen uptake was reported. This is possibly related to the muscle damage from the repeated eccentric contractions.
Fatigue
An article discussing fatigue without addressing the right nutritional supplementation would be unique in 2019. Nitrate-rich beetroot has been extensively studied in the past years since the functional component nitric oxide (NO) plays an important role in blood flow regulation during exercise. The influence of acute NO on vascular function, tissue oxygenation and neuromuscular fatigue has been determined during a knee extension task. Verges et al. (2019) [7] controversially found that there were no significant improvements on the peripheral and central mechanisms of the neuromuscular systems after acute supplementation with NO. The muscle and cerebral oxygenation remained stable however supplementation of nitrate, arginine and citrulline did lead to an improved post-ischemic vasodilatation. Translating this to athletes the researchers did not see an improved exercise performance, therewith concluding NO is not the limiting factor during knee extensions.
With research domains collaborating and flowing into each other we are excited to see what 2020 will bring in the domain of movement sciences. Will the improvement from hypoxia training on the peripheral tissue be counteracted by the negative aspects on the cerebral tissue? Can the important decisions from the team captain be quantified with the aid of hyper scanning during real-life sports matches? We hope to see these questions and many more answered with the publications of the coming year.
“It was a true delight to read the articles from last year and we like to thank you all for your nice publications. We hope to see many more in the future.”
References:
[1] https://www.merriam-webster.com/words-at-play/word-of-the-year/they
[2] Pelicioni, P. H., Tijsma, M., Lord, S. R., & Menant, J. (2019). Prefrontal cortical activation measured by fNIRS during walking: effects of age, disease and secondary task. PeerJ, 7, e6833.
[3] https://www.artinis.com/nirs-devices
[4] McKnight JC, Bennett KA, Bronkhorst M, Russell DJF, Balfour S, Milne R, Bivins M, Moss SEW, Colier W, Hall AJ, Thompson D. Shining new light on mammalian diving physiology using wearable near-infrared spectroscopy. PLoS Biol. 2019 Jun 18;17(6):e3000306.
https://www.artinis.com/blogpost-all/2019/submersible-nirs-a-very-wet-lab
[5] Woorons X, Millet GP, Mucci P. Physiological adaptations to repeated sprint training in hypoxia induced by voluntary hypoventilation at low lung volume. Eur J Appl Physiol. 2019 Jul 8.
[6] Giovanelli N, Biasutti L, Salvadego D, Alemayehu HK, Grassi B, Lazzer S. Changes in Skeletal Muscle Oxidative Capacity After a Trail Running Race. Int J Sports Physiol Perform. 2019 Jun 12:1-22.
[7] Le Roux‐Mallouf, T., Laurent, J., Besset, D., Marillier, M., Larribaut, J., Belaidi, E., ... & Verges, S. (2019). Effects of acute NO precursor intake on peripheral and central fatigue during knee extensions in healthy men. Experimental physiology.
