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Following treadmill accommodation and a 3-day period of tapered running, ten well-trained male distance runners [x maximum oxygen uptake (VO2max) = 71.3 ml.kg-1.min-1] performed two 10-min level treadmill runs designed to assess running economy at 90% VO2max. Video recordings were obtained during the last minute of each run to quantify selected gait descriptors. Two to 3 days following the second economy run, each subject completed 30 min of high-intensity (HI) running at 90% VO2max. One 2, and 4 days after the HI run, subjects repeated the 10-min economy runs. Compared to pre HI-run values, no significant change (P > 0.05) in running economy was observed during the post-HI runs. Biomechanical analyses also revealed that running style remained unaltered after the HI run. These results support earlier findings obtained on moderately trained subjects featuring measurement of running economy and gait mechanics at less-demanding intensities and suggest that among well-trained athletes, 30 min of HI running does not elicit an increase in VO2 or disrupt gait mechanics over the short term in subsequent distance runs performed at near-maximal speeds.

Purpose: The purpose of the study was to explore how individuals in the United States of America applied BFR/KAATSU devices and administered BFR/KAATSU training. In addition, the study sought to examine safety topics related to BFR/KAATSU training.Methods: The study was completed using survey research. Subjects were recruited through Facebook, email, and word of mouth. The survey was developed, piloted, and finally deployed March 22, 2021-April 21, 2021.Results: In total, 148 consented to the research; 108 completed the survey, and of those 108, 70 indicated current use with BFR/KAATSU equipment. Professions represented included athletic training, personal training, physical therapy, and strength and conditioning. Among those currently using BFR/KAATSU training (n = 70), the following results were found. The most common devices used were inflatable devices (n = 43, 61.4%). Education completed prior to device administration was formal (n = 39, 55.7%) and/or self-directed (n = 37, 52.9%). Barriers were faced by 29 (41.4%) when trying to enact training. Techniques and parameters varied during application. Screening processes were used (n = 50, 71.4%) prior to training. The devices were used to determine restrictive pressure (n = 31, 44.3%), and a supine position was used most when determining initial restrictive pressure (n = 33, 47.1%). For subsequent restrictive pressure measurements, respondents repeated the same method used initially (n = 38, 54.3%). Workload was often defined as the length of time under tension/load (n = 22, 31.4%) and exercise was directly supervised (n = 52, 74.3%). Adverse effects included bruising, lightheadedness, and cramping (n = 15, 21.4%). The devices have also been applied on those with pathology (n = 16, 22.9%).Conclusion: Those using blood flow restriction/KAATSU devices came from several professions and used an assortment of devices for BFR/KAATSU training. Individuals applied devices using a variety of parameters on populations for which efficacy has and has not been well defined.

This longitudinal investigation examined the shift from use of a marking time to an alternating stepping pattern by young children. A set of twin males was videotaped between ages 37 and 46 months climbing stairs of 3.8-17.8 cm height. One boy began to alternate consistently on the highest steps at 41 months, the other at 46 months. Anthropometrics (leg lengths) and a measure of foot overshoot (maximum height of the foot over the stair) were used to investigate the timing of the shift for the 2 boys. Magnitude of overshoot decreased with age and with increased use of the more advanced pattern. Immature balance and an initial need to visually guide the foot to the next step may be important factors in the timing of the pattern shift.The ontogenesis of walking has been extensively investigated (2, 5). There has been little systematic study, however, of developmental changes in walking in different contexts, such as stair climbing. McCaskill and Wellman (4) validated emergence and change of a variety of common motor tasks, including stair climbing. They reported a motor age of 24 months for climbing a "short" flight of stairs using a marking time pattern. Marking time is an action during which one foot meets the other on a riser, before going to the next higher (or lower) riser. Children used an alternating pattern by 31 months. By 41 months, they were able to climb a "long" flight without a hand hold. McCaskill and Wellman (4) did not analyze the form of motor patterns beyond general categories of marking time or alternating stepping patterns.Ulrich et al. (6) investigated stair-climbing behaviors in children 8 to 25 months of age. They were interested in discovering what information infants and young children used to determine the "climbability" of stairs of different heights. For example, were steps climbable based on the relationship of riser height to body-scaled parameters, such as leg length? Ulrich et al. found young children's (8-18 months) choice of stairs was related to previous walking experience, as well as exposure to stairs. Children who had been walking longer or who had more experience tended to select stairs of medium height (15.2 cm). Children who were not yet walking chose shorter (7.6 cm) stairs. Older children (18-25 months) also viewed stairs as affording many other activities, beyond

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