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.

This study examines how different exercise types affect heart rate variability (HRV) and muscle oxygen saturation in athletes specializing in rowing and long-distance running. Eighteen male athletes participated, performing a graded exercise test on the first day and a 6-minute exercise at a target heart rate on the second day. Findings revealed that during the initial 2 minutes of the target heart rate test, runners exhibited higher RR intervals compared to rowers. Additionally, muscle oxygen saturation in both muscle groups was higher in runners during the first minute. During recovery, significant differences in RR values were observed within the first 90 seconds for both groups. These results suggest that autonomic control processes during acute recovery differ qualitatively between muscle groups of varying sizes engaged in different exercise types, even when heart rate levels are similar.

The study examines the relationship between Speed Reserve Ratio (SRR), muscle oxygenation (SmO₂), and blood lactate levels in Division I middle-distance runners. Results show that athletes with a higher SRR tend to have lower VO₂ max but greater muscle oxygenation changes during exercise. A strong correlation was found between muscle oxygenation and maximal sprint speed (MSS), suggesting that faster sprinters experience greater SmO₂ variations. These findings indicate that monitoring SmO₂ can provide valuable insights into aerobic and anaerobic performance. The study highlights the potential for individualized training strategies based on SRR and muscle oxygenation data.

The study examines energy conversion and recovery processes in artistic gymnastics ring apparatus performances. Given the intense upper-body engagement required, it explores how energy systems are utilized, muscle fatigue develops, and recovery occurs. Understanding these factors is crucial for performance optimization and athlete well-being.

This study examines how varying exercise intensities affect muscle oxygenation. Utilizing multiple near-infrared spectroscopy (NIRS) devices, the research measures oxygen levels in specific muscles during exercises of differing intensities. The findings aim to enhance our understanding of muscle oxygenation dynamics, potentially informing more effective training and rehabilitation protocols.