The influence of strength-endurance training on the oxygenation of isometrically contracted forearm muscles

Abstract

Ice-climbers frequently use the squeezing of rubber rings for increasing their isometric strength-endurance in the forearm muscles. The aim of this study was to ascertain whether such training influences oxygenation and endurance of forearm muscles at higher as well as lower testing intensities. Fourteen healthy young ice-climbers were divided and randomized into two groups. Group A performed a specific ice-climbing test, an ice-axe-grasping (axe weight 750 g) until fatigue. Group B performed 150 N isometric hand-squeezing of dynamometer until fatigue. Both groups performed similar training of squeezing a rubber ring at 30% of Maximal Voluntary Contraction (MVC) for 6 weeks. The forearm oxygenation was assessed by relative saturation of oxygen (RSO(2)), total hemoglobin concentration (RTOTHb), the concentration of oxygenated hemoglobin (ROXYHb) and concentration of deoxygenated hemoglobin (RDEOXYHb). The results revealed that muscle strength-endurance training increased performance of forearm muscles during 150 N contraction with an accompanied increase in oxygenation of the exercising muscles. In contrast, the same training did not influence the performance of forearm muscles during ice-axe-grasping in spite of increased oxygenation. Muscle oxygenation during intense isometric contraction is low in spite of an increase observed in training. This may be due to oxygenation levels that were below the limit where oxygenation may influence the duration of the contraction. Increased oxygenation may have occurred due to an increased blood flow and perfusion through superficial muscles or layers may not have contributed to the generation of the force of the contraction, as would be the case in deeper muscle layers.

Neurobiological Degeneracy and Affordance Perception Support Functional Intra-Individual Variability of Inter-Limb Coordination during Ice Climbing

“…Beginners mostly used horizontally- and diagonally-located angular positions (since limb anchorages are at the same level for the horizontal angle, the arms or legs appear in an in-phase coordination mode) (Figure 5 displays two examples of an angle-time curve of beginners). This strategy of motor system (re)organization led them to maintain a static “X” body position with arms and legs extended or with arms flexed and legs extended, which was likely to be achieved at a high energy cost and resultant fatigue, due to long periods of isometric muscle contraction [57]. Conversely, experts exhibited multi-stability in their inter-limb coordination patterns (e.g., horizontal-, diagonally-, vertical- and crossed located angular positions) to achieve their task goals (Figure 6 displays two examples of an angle-time curve of experts).…”

Wireless near-infrared spectroscopy of skeletal muscle oxygenation and hemodynamics during exercise and ischemia

“…Spectrum overlap prevents distinction between Hb and Mb, but with continuous wave (CW) NIRS instruments using multiple NIR wavelengths, it is possible to use software algorithms to derive chromophore concentrations from raw optical data, and distinguish between oxy-and deoxy-hemoglobin/myoglobin (O 2 Hb/O 2 Mb and HHb/HMb). The feasibility of conventional CW NIRS in monitoring the pattern of skeletal muscle chromophore changes during rest, isometric exercise and ischemia is reported by different investigators [3][4][5][6]. NIRS has contributed new knowledge related to muscle physiology at a basic science level, is widely used as a measure of performance in exercise science, [7][8][9] and also to monitor muscle hypoxia and ischemia in sports medicine [10].…”

Monitoring Detrusor Oxygenation and Hemodynamics Noninvasively during Dysfunctional Voiding

“…The noninvasive optical methodology described for studying the detrusor is based on established principles and a body of research in other organs and tissues, as is the methodology explained for interpreting the potential physiologic relevance of NIRS data. Simultaneous NIRS and UDS studies done to date, additional urologic research using wireless NIRS [9–11, 24], and the body of NIRS studies in muscle [2–4, 23, 25–28] offer urologists an opportunity to evaluate where abnormal detrusor hemodynamics or oxygen supply and demand underlie voiding dysfunction due to BPH. This novel information has the potential to add to greater understanding of the pathophysiology underlying male LUTS because this is a condition which is recognized to be a heterogeneous clinical syndrome that probably has multiple causes of which BOO is only one [15, 16].…”

“…It is probable that what is observed is physiologic because similar patterns of change are seen in health and disease in studies involving voluntary muscle [2–4, 23, 25–28], and the bladder responds to specific physiologic events, including the effects of oxygen debt due to hypoxia or fatigue, and reduced blood flow or ischemia, with NIRS patterns that match those seen in other tissues [8, 11, 20, 25]. …”

“…However, in patients with pathologies that increase metabolic demand and/or impair the normal response of the microcirculation, abnormalities do occur and oxygen debt does develop. Under these circumstances during work involving contraction the functional capacity of the muscle or organ is adversely affected and symptoms of dysfunction result [2, 8, 9, 25, 28, 32]. …”