This study examined the effects of Sprint Interval Cycling (SIT) on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (_IFT). Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP) and a control group (CON). The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS) measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2), tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb), total tissue haemoglobin (tHb) and tissue oxygenation (TSI %) were taken. In the EXP group (5.34±0.14 to 5.50±0.14m.s^-1) but not the CON group (pre = 5.37±0.27 to 5.39±0.30m.s^-1) significant changes were seen in the 30-15_IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (−7.59±0.91 to −12.16±2.70%); ΔHHb+HMb (35.68±6.67 to 69.44±26.48μM.cm); and ΔHbO2+ MbO2 (−74.29±13.82 to −109.36±22.61μM.cm). No significant differences were seen in ΔtHb (−45.81±15.23 to −42.93±16.24). NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes.

The development of an underwater near-infrared spectroscopy (uNIRS) device has enabled previously unattainable measurements of peripheral muscle hemodynamics and oxygenation to be taken within the natural aquatic environment. The purposes of this study were (i) to trial the use of uNIRS, in a real world training study, and (ii) to monitor the effects of a swim training program upon muscle oxygenation status in short distance swimming. A total of 14 junior club level swimmers completed a repeated swim sprint test before and after an eight week endurance training program. A waterproof, portable Near-Infrared Spectroscopy device was attached to the vastus lateralis. uNIRS successfully measured changes in muscle oxygenation and blood volume in all individuals; rapid sub-second time resolution of the device was able to demonstrate muscle oxygenation changes during the characteristic swim movements. Post training heart rate recovery and swim performance time were significantly improved. uNIRS data also showed significant changes. A larger rise in deoxyhemoglobin during individual sprints suggested training induced an increase in muscle oxygen extraction; a faster recovery time for muscle oxygenation suggested positive training induced changes and significant changes in muscle blood flow also occur. As a strong correlation was seen between an increased reoxygenation rate and an improved swim performance time, these findings support the use of uNIRS as a new performance analysis tool in swimming.

Maturation-related changes in body dimensions and performance can lead to physical mismatches and drop out from youth sport. Here, we propose a new method termed ‘discreet performance banding’ (DPB). We aimed to determine if dividing youths by actual physical performance of a discreet skill or ability (‘change or direction’ [COD] ability) could discriminate between the most and least skilled players better than a marker of implied performance, such as an assessment of biological maturation. 182 male academy Spanish soccer players (age: 13-18 years height: 143 to 188 cm; mass: 32.3 to 81.4 kg) were divided into maturation groups (Tanner stages 2 through 5) and COD groups (‘fast’, ‘intermediate’ and ‘slow’). Players’ skills (passing, shooting, ball control) were evaluated on a six-point scale with a value of ‘1’ considered ‘very bad’ and a value of ‘6’ as ‘very good’. When divided by maturity status, analyses revealed no significant differences between groups in soccer skill. However, when divided into COD groups, the analyses revealed significant differences between the fast and intermediate players ([p < 0.001] favouring the fast group) and between the intermediate and slow players ([p < 0.026] favouring the slow group). There was no significant difference in skill between the fast and slow groups, though the fast group demonstrated a higher skill level as indicated by a small effect size. Fast players were more skilful than both the intermediate and slower players, indicating that COD status can be a differentiating factor between players of different skill levels. DPB could be used to equalise competition in youth sport and to enhance the overall level of enjoyment that youths derive from engagement in sport.