Slow component of VO2 during level and uphill treadmill running : relationship to aerobic fitness in endurance runners

The aim of this study was to compare the oxygen uptake (VO^sub 2^) slow component (SC) during level and uphill running in endurance runners, and to identify associations between the SC and the following aerobic fitness indicators: peak VO^sub 2^, running speed associated with the peak VO^sub 2^ (Vpeak), running speed at the lactic threshold and the VO^sub 2^ fraction elicited at the lactic threshold. Fourteen male endurance-trained runners underwent several 6-min bouts of level (LTR) and 10.5% uphill treadmill running. VO^sub 2^ SC was calculated as the difference between mean VO^sub 2^ during the 6th and the 3rd minutes. The highest mean values for the SC were 181.9±240.2 mL*min^sup -1^ for level running at ~94% peak VO^sub 2^ and 105.4±154.6 mL*min^sup -1^ for uphill running at ~90% peak VO^sub 2^. The SC observed during the last bout of the LTR correlated with peak VO^sub 2^ and with Vpeak (-0.71 and -0.76, P<0.05, respectively). The results show that for endurance-trained runners the magnitude of the SC is not affected by the treadmill gradient and that within a homogeneous sample of endurance-trained runners the SC does not correlate with indicators of aerobic fitness.

Global positioning system data analysis: velocity ranges and a new definition of sprinting for field sport athletes

Global positioning system (GPS) technology has improved the speed, accuracy, and ease of time-motion analyses of field sport athletes. The large volume of numerical data generated by GPS technology is usually summarized by reporting the distance traveled and time spent in various locomotor categories (e.g., walking, jogging, and running). There are a variety of definitions used in the literature to represent these categories, which makes it nearly impossible to compare findings among studies.

The purpose of this work was to propose standard definitions (velocity ranges) that were determined by an objective analysis of time-motion data. In addition, we discuss the limitations of the existing definition of a sprint and present a new definition of sprinting for field sport athletes.

Twenty-five GPS data files collected from 5 different sports (men’s and women’s field hockey, men’s and women’s soccer, and Australian Rules Football) were analyzed to identify the average velocity distribution. A curve fitting process was then used to determine the optimal placement of 4 Gaussian curves representing the typical locomotor categories. 

Effects of approach velocity and foot-target characteristics on the visual regulation of step length

Two questions emerge from the literature concerning the perceptual-motor processes underlying the visual regulation of step length. The first concerns the effects of velocity on the onset of visual control (VCO), when visual regulation of step length begins during goal-directed locomotion. The second concerns the effects of different obstacles such as a target or raised surface on step length regulation. In two separate experiments, participants (Experiment 1 & 2: n=12, 6 female, 6 male) walked, jogged, or sprinted towards an obstacle along a 10 m walkway, consisting of two marker-strips with alternating black and white 0.50 m markings. Each experiment consisted of three targeting or obstacle tasks with the requirement to both negotiate and continue moving (run-through) through the target. Five trials were conducted for each task and approach speed, with trials block randomised between the six participants of each gender. One 50 Hz video camera panned and filmed each trial from an elevated position, adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. Results for the targeting tasks indicate a linear relationship between approach velocity and accuracy of final foot placement (r=0.89). When foot placement was highly constrained by the obstacle step length shortened during the entire approach. VCO was found to occur at an earlier tau-margin for lower approach velocities for both experiments, indicating that the optical variable ‘tau' is affected by approach velocity. A three-phase kinematic profile was found for all tasks, except for the take-off board condition when sprinting. Further research is needed to determine whether this velocity affect on VCO is due to ‘whole-body' approach velocity or whether it is a function of the differences between gait modes.

Validity and reliability of a voice-recognition game analysis system for field sports

The purpose of this study was to assess the ability of observers to use voice-recognition analysis to accurately classify gait transitions and quantify gait durations typical of team games. Inter-rater and intra-rater reliability was also determined. Four males were filmed performing pre-determined gait protocols, each comprising different sequences of walking, jogging. running and sprinting. Two operators independently classified gait transitions and the time spent in each gait was determined by the voice recognition system. All gait modes as measured by trained observers demonstrated statistically significant correlations (p<O.O I) to predetermined measurement criteria. The mean absolute error for all gait transitions was less than half a second (0.32-0.36 5) with the maximum percentage error being approximately 4% for the walk, jog and run gaits and 10% for sprinting. Gait classification error was low at 1-9%. The intra-rater and inter-rater reliability was consistently high ranging from r =' 0.87 to 0.99. In conclusion, observers using voice-recognition software provided valid measures of time spent in each of the four gait categories with 90% or better accuracy achieved.

Multi-core security defense system (MSDS)

Today's security program developers are not only facing an uphill battle of developing and implementing. But now have to take into consideration, the emergence of next generation of multi-core system, and its effect on security application design. In our previous work, we developed a framework called bodyguard. The objective of this framework was to help security software developers, shift from their use of serialized paradigm, to a multi-core paradigm. Working within this paradigm, we developed a security bodyguard system called Farmer. This abstract framework placed particular applications into categories, like security or multi-media, which were ran on separate core processors within the multi-core system. With further analysis of the bodyguard paradigm, we found that this paradigm was suitable to be used in other computer science areas, such as spam filtering and multi-media. In this paper, we update our research work within the bodyguard paradigm, and showed a marked improvement of 110% speedup performance with an average cost of 1.5 ms.

Assessing cultural and linquistic appropriateness of the Rose Angina questionnaire in three ethnic groups

Introduction. Meeting the needs of migrant groups in Europe requires cross-culturally valid questionnaires, a substantial challenge to researchers. The Rose Angina Questionnaire (RAQ) is an important measure of coronary heart disease prevalence. It consists of seven items that collectively yield a diagnosis of angina. It has been shown to perform inconsistently across some ethnic groups in Britain. This study aimed to assess the need for modifying the RAQ for cross-culturally valid use in the three main ethnic groups in Scotland.

Methods. Interviews were carried out with Pakistani Punjabi speakers (n=26), Chinese Cantonese speakers (n=29) and European-origin English speakers (n=25). Bilingual project workers interviewed participants and provided translation and commentary to the English-speaking researcher. Participants were asked about general and cardiovascular health beliefs and behaviours, and about attitudes to pain and chest pain. They were also asked to comment on their understanding of an existing version of the RAQ in their language.

Results. No dominant themes in the cultural construction of health, pain or cardiovascular knowledge emerged that may significantly influence RAQ response between language groups. Problems were encountered with the Punjabi and Cantonese translations of the RAQ. For example, the translation for “chest” was interpreted by some Pakistani and fewer Chinese women to mean “breasts”. “Walking uphill” was translated in Chinese as “walking the hill”, without stipulation of the direction, so that some Cantonese speakers interpreted the question as meaning walking downhill. In addition, many Chinese interpreted RAQ items to be referring to breathlessness rather than chest pain due to ambiguous wording.

Conclusion. Existing Punjabi and Cantonese versions of the RAQ should be modified before being used in multi-ethnic surveys. Current versions are unlikely to be yielding data that is comparable across groups. Other language versions also require similar investigation to study the cardiovascular health of Europe’s migrant groups.

Active recovery, training status, muscle metabolism and repeated sprint performance

This thesis found that light exercise between repeated sprints improved performance in a subsequent bout. This was attributed to a reduction in potentially fatiguing by-products within the muscle and an increased aerobic metabolism in the second sprint.

Repeated sprint ability, recovery time and aerobic fitness

Aims to ascertain whether a relationship exists between repeated sprint ability (RSA) and aerobic fitness. RSA was assessed by 3 repeated sprint sessions departing avery 15, 30, or 60 seconds. Peak oxygen uptake and running velocity at VO2peak assessed aerobic fitness. When recovery time was increased between sprints, running velocity was better maintained, repeated sprint time was faster and the decrement in running velocity was smaller. Higher Vmax scores appear related to improved RSA as measured by the better maintainance of sprinting velocity.

A novel nanoplatform for oral delivery of anti-cancer biomacromolecules

Oral administration of bio–macromolecules is an uphill task and the challenges from varying pH and enzymatic activity are difficult to overcome. In this regard, nanotechnology promises the new hope and offers advantages such as controlled release, target specific delivery, combinatorial therapy and many more. In this study, we demonstrate the formulation of a novel alginate enclosed, chitosan coated ceramic, anti cancer nano carrier (ACSC NC). These NC were loaded with multi functional anti cancer bovine lactoferrin (Lf), a natural milk based protein, for improvement of intestinal absorption, in order to develop a novel platform to carry anti cancer protein and/or peptides for oral therapy. Here we demonstrate the size, morphology, internalisation and release profiles of the nanoparticles (NC) under varying pH as perceived in human digestive system. We further determine the uptake of these particles by colon cancer cell lines by measuring the endocytosis and transcytosis of the NC. These NC can be used for future targeted protein/peptide or nucleic acid based drug delivery to treat difficult diseases including cancer.

Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance

This study investigated creatine supplementation (CrS) effects on muscle total creatine (TCr), creatine phosphate (CrP), and intermittent sprinting performance by using a design incorporating the time course of the initial increase and subsequent washout period of muscle TCr. Two groups of seven volunteers ingested either creatine [Cr; 6 × (5 g Cr-H2O + 5 g dextrose)/day)] or a placebo (6 × 5 g dextrose/day) over 5 days. Five 10-s maximal cycle ergometer sprints with rest intervals of 180, 50, 20, and 20 s and a resting vastus lateralis biopsy were conducted before and 0, 2, and 4 wk after placebo or CrS. Resting muscle TCr, CrP, and Cr were unchanged after the placebo but were increased (P < 0.05) at 0 [by 22.9 ± 4.2, 8.9 ± 1.9, and 14.0 ± 3.3 (SE) mmol/kg dry mass, respectively] and 2 but not 4 wk after CrS. An apparent placebo main effect of increased peak power and cumulative work was found after placebo and CrS, but no treatment (CrS) main effect was found on either variable. Thus, despite the rise and washout of muscle TCr and CrP, maximal intermittent sprinting performance was unchanged by CrS.

Sprint cycling performance is maintained with short-term contrast water immersion

Purpose: Given the widespread use of water immersion during recovery from exercise, we aimed to investigate the effect of contrast water immersion on recovery of sprint cycling performance, HR and, blood lactate.

Methods: Two groups completed high-intensity sprint exercise before and after a 30-min randomized recovery. The Wingate group (n = 8) performed 3 x 30-s Wingate tests (4-min rest periods). The repeated intermittent sprint group (n = 8) cycled for alternating 30-s periods at 40% of predetermined maximum power and 120% maximum power, until exhaustion. Both groups completed three trials using a different recovery treatment for each trial (balanced randomized application). Recovery treatments were passive rest, 1:1 contrast water immersion (2.5 min of cold (8-C) to 2.5 min of hot (40-C)), and 1:4 contrast water immersion (1 min of cold to 4 min of hot). Blood lactate and HR were recorded throughout, and peak power and total work for pre- and postrecovery Wingate performance and exercise time and total work for repeated sprinting were recorded.

Results: Recovery of Wingate peak power was 8% greater after 1:4 contrast water immersion than after passive rest, whereas both contrast water immersion ratios provided a greater recovery of exercise time (È10%) and total work (È14%) for repeated sprinting than for passive rest. Blood lactate was similar between trials. Compared with passive rest, HR initially declined more slowly during contrast water immersion but increased with each transition to a cold immersion phase.

Conclusions: These data support contrast water immersion being effective in maintaining performance during a short-term recovery from sprint exercise. This effect needs further investigation but is likely explained by cardiovascular mechanisms, shown here by an elevation in HR upon each cold immersion.

Profile of position movement demands in elite junior Australian rules footballers

This study investigated the positional movement patterns in elite junior Australian Football (AF). Thirty players (17.1 ± 0.9 years) participating in this study were tracked over seven home games of the regular 2006 Victorian junior (Under 18) league season. Using lapsed-time video analysis, each position for an entire match was videotaped on three separate occasions over the course of the season. Data analysed included the number of individual efforts, duration and frequency of efforts; distance and percentage time for the classifications of standing, walking jogging, running and sprinting. Results showed that the midfield position travelled the greatest distance (4173 ± 238 m per quarter; p < 0.05; ES = .94) whilst the full forward/full back travelled the least (2605 ± 348 m per quarter, p < 0.05, ES = 1.21). For all positions, walking or jogging accounted for the greatest number of efforts (45-55%), conversely running and sprinting accounted for 5-13% of match efforts. The majority of efforts across all classifications were between 0-3.99 s. The data from this study provides further evidence that AF is an intermittent sport characterised by high intensity movements separated by low intensity movements at a ratio of one high intensity effort every 12-40 s. However, careful interpretation of the data is required when training junior AF players for specific positions, given the specific group studied.

Player movement patterns in an elite junior Australian Rules Football team : an exploratory study

This study explored the physical movement patterns associated with an elite Under 18 Australian Football (AF) team. Five field positions were selected with observations recording the number and relative per cent of "working" efforts (jogging, running, and sprinting), "resting" efforts (walking) and the total distances associated with "working" or "resting" efforts. Intra-observer reliability, using test- retest method, showed correlations were r = 0.98 or greater. The Wing position covered 11,877 m, the greatest total distance during an entire game, whilst the HBF and Centre positions both recorded 11,545 m and 11,537 m respectively and the Ruck position covered 9,203 m. The HBF recorded the greatest frequency of 'working' and 'resting' efforts (180 and 182 respectively), whilst the Wing (166 and 158), Centre (162 and 149) and Ruck (161 and 166) showed similarities in their results. The Wing position recorded the longest average distance per 'working' effort (58 m) whilst the Centre position recorded the longest average distance per 'resting' effort (17 m). Results also show the completion of less total efforts and smaller total distances, in Under 18 players, recorded compared to professional senior AF data. The results from this study suggest that further in-depth research is required into movement patterns and game activity demands in this AF playing group.

Using the Rose Angina Questionnaire cross-culturally : the importance of consulting lay people when translating epidemiological questionnaires

Objectives. The Rose Angina Questionnaire (RAQ) is an important measure of coronary heart disease prevalence. It has been shown to perform inconsistently across some ethnic groups in Britain. This study investigates whether the best available versions of the RAQ in Punjabi and Cantonese were linguistically equivalent to the English version.

Design. Interviews were carried out with lay people from the Pakistani, Chinese and European-origin communities in Scotland to assess the versions of the RAQ used in the Newcastle Heart Project (the best available versions). For each questionnaire item, participants were asked to elaborate on their understanding of the question and the meaning of keywords or phrases.

Results. Problems were discovered with the Punjabi and Cantonese translations of the RAQ. For example, the translation for ‘chest’ was interpreted by some Pakistani and Chinese women to mean ‘breasts’. ‘Walking uphill’ was translated in Chinese as ‘walking the hill’, without stipulation of the direction, so that some Cantonese speakers interpreted the question as pertaining to walking downhill. Many Chinese interpreted RAQ items to be referring to breathlessness rather than chest pain due to ambiguous wording.

Conclusion. Existing versions of the RAQ are unlikely to be yielding data that are cross-culturally valid or comparable. For robust health survey research in languages other than that in which the questionnaire was developed, lay assessment of questionnaires prior to and after translation is a necessity rather than a luxury.

Stair climber smart mobile robot (MSRox)

MSRox is a wheeled mobile robot with two actuated degrees of freedom which enables it to have smooth motion on flat surfaces. It has the capability of climbing stairs and traversing obstacles, and adaptability toward uphill, downhill and slope surfaces. MSRox with 82 cm in length, 54 cm in width and 29 cm in height has been designed to climb stairs of 10 cm in height and 15 cm in width; nevertheless, it has the capability of climbing stairs up to about 17 cm in height and unlimited widt. In this paper, the motion systems and the capabilities of MSRox are described. Furthermore, experimental results of stair climbing and a comparison of the results with others are presented.