Fatigue is a known troublemaker in athletics, but can also have negative effects in physiology research. Fatigue can become a confounding variable, giving researchers data that may be less accurate or reliable.
Men and women may respond to fatigue differently, which can make obtaining good data especially difficult. In one study on fatigue by Stern et al. (2012), the researchers attempted to monitor fatigue and show different effects between men and women. This study attempted to follow a central nervous system component, as well as the peripheral nervous system. Using the BIOPAC MP160 system with AcqKnowledge software to record and analyze EMG, researchers were able to continually monitor muscle and neuron activation during the exercise tests.
The results of the study found that females had a higher rate of reduced central neural drive of the quadriceps, coupled with knee extension torque preservation. These factors, when paired together, can create a higher percentage for the possibility of knee injury for women.
With coffee being such a staple in the home (and in the lab!), researchers Smirmaul et, al (2017) wanted to see if coffee had any effect on fatigue, duration of exercise, and the perception of effort. This study used seven adult male cyclists in moderate hypoxic states to obtain their results. The experiment used a double-blind procedure, with some participants receiving no coffee. The researchers wanted to see if the coffee participant group took a longer time to reach fatigue. EMG was obtained by using BIOPAC MP160 with EMG amplifiers. The results showed that coffee has no effect on fatigue, but coffee did improve the time it took until the athletes reached exhaustion in high endurance tasks. The researchers believe that coffee lowers the perceived effort of the athlete, leading them to think they can go further.
Fatigue can also have impacts on data, even when using gold standards of measurement. A separate study done on fatigue by Neyroud et al. (2016), attempted to show that muscle fatigue has an effect on the validity of the ITT (Interpolated Twitch Technique). The ITT is used to evaluate the capacity of the central nervous system in activating skeletal muscles. This study used a BIOPAC MP system with EMG amplifiers to monitor muscle and neuron activation. Electrical stimulus was given to both samples to create fatigue, and a separate stimulus was given to mimic the ITT. This study found that peripheral fatigue factors do have an effect on the outcome of the ITT.
BIOPAC offers a variety of equipment that can be used in studies similar to the ones presented. To find more information on solutions for recording and analyzing signals such as EEG, EMG, respiration, skin conductance using the MP160/MP150, MP36, and other platforms, you can visit the individual application pages on the BIOPAC website. If you are interested in reading other related studies, visit the publications page on the BIOPAC website.