The article discusses the use of Near-infrared spectroscopy (NIRS) to measure muscle oxygenation levels in athletes to optimize their training performance. A new NIRS sensor called Train.Red FYER was developed for this purpose. The stability, accuracy, intra- and inter-variability of muscle oxygenation saturation (SmO2) were assessed using two different phantoms and in-vivo tests. The sensor was found to be stable and precise, with inter-variability being larger than intra-variability. The article concludes that the new NIRS sensor can be used to measure SmO2 accurately in athletes during endurance and strength activities.

The article discusses using Near-InfraRed Spectroscopy (NIRS) to study rest periods between strength exercises and develop a model for predicting the oxygenated recovery state. A Recurrent Neural Network (RNN) was trained to predict shifts between the four manually categorized phases of recovery. The RNN and Multi-Layer Perceptron (MLP) had similar accuracy, but the RNN was more consistent. This can help athletes design more efficient training programs.

This study explores the potential of neuromuscular electrical stimulation (NMES) to increase muscle metabolism as an alternative to exercise for individuals unable to perform traditional physical activity. Using inexpensive stimulators and tin foil electrodes, NMES was applied to four leg muscles in healthy participants, with metabolism measured via near-infrared spectroscopy during brief ischemia. Results showed significant increases in muscle metabolism. These findings suggest NMES could effectively replace or augment exercise, offering a cost-effective solution for improving health in populations with limited mobility.