Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilatory threshold

Abstract

The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (T _vent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific T _vent. Recreationally active men (n = 12) and women (n = 10) with similar values for percentage of peak oxygen consumption at T _vent participated in the study. Ventilatory equivalence, excess CO₂ and modified V-slope methods were used concurrently to determine T _vent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% T _vent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of T _vent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to T _vent.     

Book reviews

Women, sport and performance, C.L. Wells, Human Kinetics, Champaign, Illinois, 1985. xi+333 pp, $24.00 (hb), ISBN 0 931250 87 0

Research designs and statistics for physical education, Anne L. Rothstein, Prentice Hall, New York, 1985. xiii + 353 pp, £31 (hb), ISBN 0 13 774142 1

Limits of human performance, American Academy of Physical Education Papers No. 18, D.H. Clarke and H.M. Eckert (eds), Human Kinetics, Champaign, Illinois, 1985. 144 pp, £14.50 (pb), ISBN 0 931250 99 4

Sports physiology, (2nd edn) E.L. Fox, Holt Saunders, Eastbourne, 1984. xii+418 pp, £18.95 (hb), ISBN 0 03 063771 6

Sport management ‐ macro perspectives, P. Chelladurai, Sports Dynamics, London, Ontario, 1985. 191 pp, $11.95 (pb), ISBN 0 9691619 0 5

Microelectronics in the sport sciences, Charles F. Cicciarella, Human Kinetics, Champaign, Illinois (distributed in the UK by Eddington Hook & Co.), 1986. 105 pp, $12.00 (pb), ISBN 0 87322 056 0

The biomechanics of sports techniques, (3rd edn) J.G. Hay, Prentice Hall, New Jersey, 1985. xvii+539 pp, £15.95 (pb), ISBN 0 13 078304 8     

The differential effects of PNF versus passive stretch conditioning on neuromuscular performance

Abstract

The effects of flexibility conditioning on neuromuscular and sensorimotor performance were assessed near to full knee extension (25°). Eighteen males who were randomly assigned into two groups underwent eight weeks (three-times per week) of flexibility conditioning (hip region/knee flexor musculature; dominant limb) involving either proprioceptive neuromuscular facilitation (PNF) (n=9) or passive stretching (PASS) (n=9). Both modes of flexibility conditioning are popular within contemporary exercise and clinical settings and have demonstrated efficacy in improving range of motion. The contralateral limb and a prior ‘no exercise’ condition were used as controls. The PNF and PASS modes of conditioning improved passive hip flexibility to a similar extent (mean 19.3% vs. baseline, intervention limb, p<0.01) but did not alter knee flexor strength (overall mean 309.6±81 N) or sensorimotor performance (force and positional errors: 2.3±8.2% and 0.48±7.1%). Voluntary and magnetically evoked electromechanical delays (EMD_V and EMD_E, respectively) were increased but to a greater extent following PASS compared to PNF (PASS: 10.8% and 16.9% lengthening of EMD_V and EMD_E, respectively vs. PNF: 3.2% and 6.2%, p<0.01).The attenuated change to electromechanical delay (EMD) performance during PNF conditioning suggests a preserved capability for rapid muscle activation, which is important in the maintenance of dynamic joint stability. That PNF was also equally efficacious in flexibility conditioning would suggest that this mode of flexibility training should be used over passive to help preserve dynamic joint stability capabilities at this extended and vulnerable joint position.     

A Meta-Analysis of Studies Comparing Maximal Oxygen Uptake in Men and Women

Abstract

Since [Vdot]O₂ max (ml/minute · kg body weight) is known to be the primary determinant of work capacity in weight-bearing exercise, the quantification of sex-specific factors influencing aerobic capacity is necessary if appropriate work capacity and endurance performance expectations and standards are to be developed for men and women. Yet, due to varying procedures and sample characteristics, large discrepancies exist among studies concerning the magnitude of the sex difference in [Vdot]O₂ max. The purpose of this article is to provide an integrative review of the research comparing [Vdot]O₂ max in men and women using the meta-analytic strategy proposed by Glass (1976). An overall estimate of the magnitude of the sex effect for each of three expressions of [Vdot]O₂ max is provided. When removing the variability in aerobic capacity due to body size and body fatness, the magnitude of difference in [Vdot]O₂ max between men and women is substantially reduced. When expressed relative to fat-free weight, the [Vdot]O₂ max values of the males are, on the average, 12 to 15% higher than those of the females. Sex-specific differences in relative hemoglobin content may be responsible for a part of this remaining difference. However, a substantial portion of the sex difference in [Vdot]O₂ max (ml/minute · kg fat-free weight) is probably attributable to gender-associated differences in level of physical activity/conditioning. The ability to clearly identify the sex-related components of aerobic capacity is an objective warranting further investigation.     

Book reviews

Clinical sports medicine, Robert C. Cantu, (ed.), The Collamore Press, Lexington, Massachusetts, Toronto, 1984. 219 pp, £19.95 (hb), ISBN 0 669 06842 X

Sports injuries, a self‐help guide, Vivian Grisogono, John Murray Ltd, London, 1984. 293 pp, £7.95 (hb), ISBN 0 7195 4111 5

Athletes’ guide to mental training, Robert N. Nideffer, Human Kinetics, Champaign, Illinois (distributed in the UK by Eddington Hook & Co.) 1985. vii +156 pp, $9.95 (pb), ISBN 0 931250 96 X

Scientific foundations of coaching, R.R. Pate, B. McClenaghan and R. Rotella, Saunders College Publishing, Philadelphia, 1984. xii + 344 pp, £21.95(hb), ISBN 0 03 057961 9

Mathematics in sport, M. Stewart Townend, Ellis Horwood, Chichester, 1984. 202 pp (hb), ISBN 0 85312 717 4

Frontiers of exercise biology, ’Big Ten Body of Knowledge’ symposium series, Vol. 13 K.T. Borer, D.W. Edington and T.P. White (eds), Human Kinetics Publishers Inc., Champaign, Illinois, (distributed in the UK by Edington Hook & Co.), 1983. vii + 295 pp, $31.95(hb), ISBN 0 931250 49 8

The knee, Philippe Segal and Marcel Jacob, Wolfe Medical Publications, Frome, Somerset, 1984. 143 pp (hb), £15, ISBN 2 224 00887 2

Psychological foundations of sport, J.M. Silva and R.S. Weinberg (eds), Human Kinetics, Champaign, Illinois, (distributed in the UK by Eddington Hook & Co), 1984. xxiv + 528 pp, £22.50 (hb), ISBN 0 93 1250 59 5

Physical activity and the social sciences, W. Neil Widmeyer, Mouvement Publications Inc., Ithaca, 1983. 472 pp, £9.00 (pb), ISBN 0 932392 13 X     

Book Reviews

Abstract

Carter, J. E. Lindsay, and Heath, Barbara Honeyman. Somatotyping: Development and Applications. (Cambridge Studies in Biological Anthropology, 5). Cambridge: Cambridge Univenity Press, 1990. pp. xiv, 503. Reviewed by Gaston Beunen, Study Centre for Physical Development Research, Institute of Physical Education, Katholieke Universiteit Leuven

Clark, Jane E., &; Humphrey, J. H. (Eds.). Advances in Motor Development Research (Vol. 3). New York: AMS Press, 1990. pp. xi, 259. Index, references. Reviewed by Mary Ann Roberton, Bowling Green State University

Kyle, Donald G., and Stark, Gary D. (Ed.), Essays on sport History and sport Mythology. College Station, TX: Texas A&;M University Press, for the University of Texas at Arlington. pp. vi, 154. Reviewed by Synthia S. Slowikowski, University of Illinois at Urbana–Champaign

MacDougall, J. D., Wenger, H. A., &; Green, H. J. (Eds.). Physiologiml Testing ofthe High Peifonnance Athlete. Champaign, IL: Human Kinetics, 1991. Pp, vii, 424. Tables, figures, photos, references. Reviewed by Paul Vaccaro, University of Maryland

Malina, Robert M., and Bouchard, C. Growth, Maturation, and Physical Activity. Champaign, IL: Human Kinetia, 1991, pp. 501. Index. Reviewed by Kathleen Haywood, University of Missouri–St. Louis

Metzler, M. Instructional Supervision for Physical Education. Champaign, IL: Human Kinetics, 1990. pp. vii, 248. References, index. Reviewed by Paul Paese, Southwest Texas State University

Parkhouse, Bonnie L, (Ed.). The Management of Sport: Its Foundation and Application. St. Louis: Mosby–Year Book, 1991, Pp. xviii, 404. Reviewed by Kathleen Davis, Northeastern University

Thomas, Jerry R., and Nelson, Jack K. Researda Methods in Physical Activity (2nd ed.), Champaign, Il.: Human Kinetics. 1990. 568 pp. Appendixes. Reviewed by Susan J. Hall, California State University, Northridge

Wells, Christine L. Women, sport, and Performance: A Physiological Perspective (2nd ed.) Champaign, IL: Human Kinetics. 1991, 367 pp. Reviewed by Ann Ward, University of Massachusetts Medical Center     

Effect of sand versus grass training surfaces during an 8-week pre-season conditioning programme in team sport athletes

Abstract

This study compared the use of sand and grass training surfaces throughout an 8-week conditioning programme in well-trained female team sport athletes (n = 24). Performance testing was conducted pre- and post-training and included measures of leg strength and balance, vertical jump, agility, 20 m speed, repeat speed (8 × 20 m every 20 s), as well as running economy and maximal oxygen consumption (VO_2max). Heart rate (HR), training load (rating of perceived exertion (RPE) × duration), movement patterns and perceptual measures were monitored throughout each training session. Participants completed 2 × 1 h conditioning sessions per week on sand (SAND) or grass (GRASS) surfaces, incorporating interval training, sprint and agility drills, and small-sided games. Results showed a significantly higher (P < 0.05) HR and training load in the SAND versus GRASS group throughout each week of training, plus some moderate effect sizes to suggest lower perceptual ratings of soreness and fatigue on SAND. Significantly greater (P < 0.05) improvements in VO_2max were measured for SAND compared to GRASS. These results suggest that substituting sand for grass training surfaces throughout an 8-week conditioning programme can significantly increase the relative exercise intensity and training load, subsequently leading to superior improvements in aerobic fitness.     

Validity of a Tympanic Thermometer and Thermal Imaging Camera for Measuring Core and Skin Temperature during Exercise in the Heat

ABSTRACT

This study compared criterion to minimally invasive, practical measures of core (T_c) and skin (T_sk) temperature during 30 min of moderate-intensity cycle exercise in a heat chamber (35°C, 60% rH). T_c was monitored using a core temperature pill (T_c(Pill)) and tympanic thermometer (T_c(Tymp)) during rest, exercise, and recovery in 15 participants. T_sk was monitored using hard-wired skin thermistors attached to a data logger (T_sk(T)) and a thermal imaging camera (T_sk(IR)) in 11 participants. T_c measurement resulted in no significant difference (p > 0.05), a mean bias of 0.1°C, coefficient of variation (CV%) of 1.0%, and correlation of r = 0.74 between devices. T_sk measurement resulted in a significant difference (p = 0.01), a mean bias of 0.6°C, CV% of 2.3%, and correlation of r = 0.61 between devices. T_c(Tymp) demonstrated acceptable agreement with T_c(Pill); however, caution is advised when using T_sk(IR) to give accurate measures of T_sk during exercise.     

Effect of sulphurous mineral water in haematological and biochemical markers of muscle damage after an endurance exercise in well-trained athletes

Abstract

To investigate the effects of sulphurous mineral water (SMW) after a hydroponic treatment on muscle damage, antioxidant activity and peripheral blood changes induced by submaximal exercise. Thirty well-trained male triathletes were supplemented with SMW or placebo: 3 weeks of placebo, 30 days of wash out and 3 weeks of SMW. After both periods, participants ran for 2 h at 70% maximal aerobic speed. Antioxidant enzymes, lipid peroxidation, antioxidant capacity and blood cell markers were compared between placebo and SMW at pre-exercise (T₀), immediately post-exercise (T₁), 24 h post-exercise (T₂) and 48 h post-exercise (T₃). Total thiols decreased until T₃ vs. T₀ for both placebo and SMW; transient red blood cells, haemoglobin and haematocrit increased were shown at T₁ vs. T₀ and for leucocytes until T₂ vs. T₀, only for placebo group. Total thiols increased significantly in SMW vs. placebo at T₀; Thiobarbituric acid reactive species was significantly higher at T₀, T₁, T₂ and T₃; catalase increased significantly at T₁; creatine phosphokinase decreased significantly at T₁, T₂ and T₃, although no significant differences were found at T₀. Furthermore, red blood cells, haemoglobin and haematocrit were significantly higher and leucocytes were significantly lower at T₀ and T₁ in SMW group vs. placebo group. This study suggests that three weeks of SMW supplementation may protect from exercise-induced muscle damage.     

Heart Rate Holter Monitoring of 6- and 7-Year Old Children with Insulin Dependent Diabetes Mellitus Cardiovascular and Short Term Metabolic Response to Exercise: A Pilot Study

Abstract

This study examined whether gender and/or training were related to the exercise-induced changes in plasma concentrations of growth hormone (GH), prolactin (PRL), triiodothyronine (T₃), and thyroxine (T₄). Twenty subjects (male and female 10-km runners; untrained males and females) ran on a treadmill for 30 win at 80% of previously determined maximum heart rate. Blood samples were taken through an indwelling catheter from an antecubital vein at ?30, 0, +15, +30 min of the test and 30 min of recovery. Reded temperature rose significantly (p < .01) at +15 and +30 min with concomitant rise in GH concentration, but PRL, T₃, and T₄ were not affected by the exercise. We concluded that a 30-min run at 80% of maximum heart rate is associated with higher concentrations of GH but not of PRL, T₃, and T₄ Neither training state nor gender affected the aforementioned results.     

System approach to games and competitive playing

Abstract

The force enhancement of muscle twitch contraction after a maximal voluntary contraction (MVC) has been defined as post-activation potentiation. However, the effects of post-activation potentiation on ballistic movements have not been studied extensively, or the underlying neurophysiologycal mechanism. In the current study, we examined post-activation potentiation and spinal H-reflex excitability in the soleus muscle. Mechanical power during explosive ballistic plantar flexions was measured in 14 males before and after 5 s, 4 min, and 10 min of isometric conditioning (EPF_pre, EPF_5s, EPF_4min, EPF_10min, respectively). Four sessions corresponding to four different protocols of isometric conditioning were conducted. The protocols were different in the intensity (10% vs. 100% of MVC) and duration (7 vs. 10 s) of the isometric conditioning. The results showed a significant enhancement in mechanical power in EPF_4min compared with EPF_pre, only when the isometric conditioning was performed at 100% of MVC for 10 s. No significant changes were observed in the H-related parameters (e.g amplitude, threshold, H/M ratio) after the isometric conditioning. Our results show that to obtain a post-activation potentiation during explosive ballistic movements, the intensity and duration of the isometric conditioning must be controlled. Moreover, the improvement in mechanical power is not related to spinal H-reflex excitability.     

Effects of plyometric jump training on the physical fitness of young male soccer players: Modulation of response by inter-set recovery interval and maturation status

ABSTRACT

The effects of plyometric jump training on the physical fitness of male youth (age = 10–17 years) soccer players was examined in relation to inter-set recovery intervals and the maturity of the players in a single-blind, randomized-and controlled crossover trial. Jumping tests and kicking velocities were measured before (T₀), after a 6 week control period (T₁), after 6 weeks of plyometrics (T₂), after 6 weeks of wash-out (T₃), and after a further 6 weeks of plyometrics (T₄). Subjects were divided into pre- and post- peak-height-velocity (PHV) groups, and were randomly assigned to 30 s or 120 s inter-set intervals during periods T₂ and T₄. Any changes in jumping and maximum kicking velocities during T₁ and T_3, had trivial effect sizes (0.01–0.15), but small to moderate improvements (effect size = 0.20–0.99) were observed in both groups during T₂ and T₄. Gains in pre-PHV players were similar for the two inter-set intervals, but gains in post-PHV players were greater (p < 0.05) with an inter-set recovery of 120 s than with a 30 s recovery. We conclude that plyometric jump training improves the physical fitness of adolescents, irrespective of their maturity, but that in older individuals gains are greater with a longer inter-set recovery interval.     

Book Reviews

Abstract

Richard Cashman, Sport in the National Imagination: Australian Sport in the Federation Decades, Walla Walla Press, 2002, Pp. Vi + 282, $(A)29.95, ISBN 1 876718 48x Paperback.

Mike Huggins, Horseracing and the British, 1919-1939, Manchester, Manchester University Press, 2003, Cloth £49.99 ISBN 0719065283, Paper £16.99, ISBN 0719065291 Pp, Xvii + 230.

Arnd Krüger And William Murray (Eds.), The Nazi Olympics: Sport, Politics and Appeasement in the 1930s, Urbana And Chicago, University Of Illinois Press, 2003, Pp.Ix + 262. $44.95. ISBN 0-252-02815-5.

Doug Laughton (With Andrew Quirke), A Dream Come True: A Rugby League Life, London League Publications Ltd. October 2003, 164 Pages + Forword &; Publisher's Promotional Pages, ISBN: 1-903659-12-4.

Randy Roberts, Jack Dempsey: The Manassa Mauler, Urbana: The University Of Illinois Press, 2003, Pp Xiii + 314. $19.95 ISBN 0-252-07148-4

Russell Sullivan, Rocky Marciano: The Rock Of His Times. Sport And Society. Urbana, II: University Of Illinois Press, 2002. Pp. Xii + 368. Illustrated, Bibliography, Notes. $34.95     

‘It doesn't matter how they move really,as long as they move.’ Physical education teachers on developing their students’ movement capabilities

Background: Movement is key in physical education, but the educational value of moving is sometimes obscure. In Sweden, recent school reforms have endeavoured to introduce social constructionist concepts of knowledge and learning into physical education, where the movement capabilities of students are in focus. However, this means introducing a host of new and untested concepts to the physical education teacher community.

Purpose. The purpose of this article is to explore how Swedish physical education teachers reason about helping their students develop movement capability.

Participants, setting and research design. The data are taken from a research project conducted in eight Swedish secondary schools called ‘Physical education and health – a subject for learning?’ in which students and teachers were interviewed and physical education lessons were video-recorded. This article draws on data from interviews with the eight participating teachers, five men and three women. The teachers were interviewed partly using a stimulated recall technique where the teachers were asked to comment on video clips from physical education lessons where they themselves act as teachers.

Data analysis. A discourse analysis was conducted with a particular focus on the ensemble of more or less regulated, deliberate and finalised ways of doing things that characterise the eight teachers’ approach to helping the students develop their movement capabilities.

Findings. The interviews indicate that an activation discourse (‘trying out’ and ‘being active’) dominates the teachers’ ways of reasoning about their task (a focal discourse). When the teachers were specifically asked about how they can help the students improve their movement capacities, a sport discourse (a referential discourse) was expressed. This discourse, which is based on the standards of excellence of different sports, conditions what the teachers see as (im)possible to do due to time limitations and a wish not to criticise the students publicly. The mandated holistic social constructionist discourse about knowledge and learning becomes obscure (an intruder discourse) in the sense that the teachers interpret it from the point of view of a dualist discourse, where ‘knowledge’ (theory) and ‘skill’ (practice) are divided.

Conclusions. Physical education teachers recoil from the task of developing the students’ movement capabilities due to certain conditions of impossibility related to the discursive terrain they are moving in. The teachers see as their primary objective the promotion of physical activity – now and in the future; they conceptualise movement capability in such a way that emphasising the latter would jeopardise their possibilities of realising the primary objective. Should the aim be to reinforce the social constructionist national curriculum, where capability to move is suggested to be an attempt at formulating a concept of knowledge that includes both propositional and procedural aspects and which is not based on the standards of excellence of either sport techniques or motor ability, then teachers will need support to interpret the national curriculum from a social constructionist perspective. Further, alternative standards of excellence as well as a vocabulary for articulating these will have to be developed.     

Notices

Kinanthropometry III. Proceedings of the VIII Commonwealth and International Conference on Sport, Physical Education, Dance, Recreation and Health. T. Reilly, J. Watkins and J. Borms (eds), E. &; F.N. Spon, London, 1986, xii + 312 pp, £25 (hb), ISBN 0 419 13970 2

Sensible fitness. J.H. Wilmore, Human Kinetics, Champaign, Illinois, USA, 1986, xii + 300 pp, $11.95, ISBN 0 88011 270 0

Running without fear. K.H. Cooper, Bantam Books, London, 1985, 256 pp, £3.95, ISBN 0 553 17356 1

Athletic training and sports medicine. American Academy of Orthopaedic Surgeons, Churchill Livingstone, Chicago, USA, 1986. viii + 602 pp, £40, ISBN 0 89203 002 X

Athletics and the heart. R. Rost, Year Book Medical Publishers Inc., Chicago, 1987, vii+159 pp, £21.50 (pb), ISBN 0 8151 7397 0

Psychology and sociology of sport: current selected research, Volume 1. L.V. Velden and J.M. Humprey (eds), AMS Press, New York, 1986, ix + 237 pp, £49.50 (hb), ISBN 0 404 63401 X     

A comparison of accelerometry analysis methods for physical activity in older adult women and associations with health outcomes over time

ABSTRACT

This study compared five different methods for analyzing accelerometer-measured physical activity (PA) in older adults and assessed the relationship between changes in PA and changes in physical function and depressive symptoms for each method. Older adult females (N = 144, M_age = 83.3 ± 6.4yrs) wore hip accelerometers for six days and completed measures of physical function and depressive symptoms at baseline and six months. Accelerometry data were processed by five methods to estimate PA: 1041 vertical axis cut-point, 15-second vector magnitude (VM) cut-point, 1-second VM algorithm (Activity Index (AI)), machine learned walking algorithm, and individualized cut-point derived from a 400-meter walk. Generalized estimating equations compared PA minutes across methods and showed significant differences between some methods but not others; methods estimated 6-month changes in PA ranging from 4 minutes to over 20 minutes. Linear mixed models for each method tested associations between changes in PA and health. All methods, except the individualized cut-point, had a significant relationship between change in PA and improved physical function and depressive symptoms. This study is among the first to compare accelerometry processing methods and their relationship to health. It is important to recognize the differences in PA estimates and relationship to health outcomes based on data processing method.

Abbreviation: Machine Learning (ML); Short Physical Performance Battery (SPPB); Center of Epidemiologic Studies Depression Scale (CES-D); Physical Activity (PA); Activity Index (AI); Activities of Daily Living (ADL)     

Mechanics of standing and crouching sprint starts

The aim of this study was to compare the kinetic and kinematic parameters of standing and crouch sprint starts. Parallel starts (PS), false starts (FS), jump starts (JS) and crouch starts (3PS) were compared. Eighteen participants performed each start on a force plate and six infrared cameras captured the three-dimensional coordinates of 36 retro-reflective markers. Performance during a five-metre sprint (T_5m) was analysed. Duration of the start phase (T_start), mean values of horizontal and total ground reaction forces (GRFs) (F_{x_mean} and F_{tot_mean}), ratio of force (RF), maximal power (P_max) and kinetic energy (KE) of each limb were calculated. Significant differences were found for T_5m, T_start, KE, P_max, F_{x_mean}, F_{tot_mean} and RF for the crouch start compared to the other starts (P ≤ 0.05). Significant correlations were found between T_5m and T_start (r = 0.59; P ≤ 0.001), and T_5m and P_max, F_{x_mean} and RF (?0.73 ≤ r ≤ ?0.61; P ≤ 0.001). To conclude, the crouch start resulted in the best performance because T_start was shorter, producing greater P_max, F_{x_mean} with a more forward orientation of the resultant force. Greater KE of the trunk in each start condition demonstrated the role of the trunk in generating forward translation of the centre of mass (CM).     

Relationship between vertical stiffness and soft-tissue injuries in professional Australian football

ABSTRACT

Soft-tissue injuries are common in Australian football. Recently, literature has identified non-modifiable and modifiable risk factors, including vertical stiffness (K_vert). However, limitations regarding measurement frequency and duration exist; thus, further information is required about the role of K_vert as a modifiable risk factor for injury. This study examined the seasonal variation in K_vert and its relationship to soft-tissue injuries in professional Australian football. The mean K_vert and bilateral asymmetry were assessed and compared between injured and non-injured players. For the seasonal analysis, 56 players were tested across two seasons with no variation in bilateral asymmetry evident (p= 0.33). While there were generally no changes in K_vert, the value from the end of the second pre-season revealed 5% lower values than the mean of two seasons (p= 0.02). Considering the injury analysis, 21 lower-body soft-tissue injuries were recorded from 18 participants. No differences were recorded for mean K_vert between the injured and non-injured groups (p= 0.16–0.76). When assessing K_vert asymmetry, the injured group displayed a 4.5% higher value than the non-injured group at the end of the pre-season test (p= 0.03) but not at other time-points (p= 0.16–0.99). Higher K_vert bilateral asymmetry measures after the pre-season appear to be related to lower-body soft-tissue injury in professional Australian footballers. Medical and conditioning staff should consider this measure when trying to mitigate the onset of injury or identify at-risk players.     

Exercise-induced bronchospasm among athletes in Lower Silesia Province

Abstract

A few studies have reported data on the prevalence of exercise-induced bronchospasm in high school and university athletes. Recently published data suggest that exercise-induced bronchospasm may affect up to 39% of American university athletes. To date, no data describing this pathology in athletes from Central Europe have been published. The aim of the present study was to establish the prevalence of exercise-induced bronchospasm in pupils attending sports mastership classes in secondary school as well as students of the University of Physical Education in Wroclaw. The participants were 77 athletes (30 women and 47 men) aged 16–27 years (mean 17.3 years). Only one athlete (1.29%) diagnosed with atopic asthma before testing experienced a fall in forced expiratory volume in one second (12.9% FEV₁) compared with baseline, which showed that the exercise test result was positive. From a clinical point of view, the ventilation disturbance was asymptomatic. In the other participants, there were slight but statistically significant rises in FEV₁ (P < 0.02). The results of our study indicate a very low prevalence of exercise-induced bronchospasm in the population of athletes examined.     

Age,Height, Weight,and Grip Strength

Abstract

This study recorded the age, height, weight, and grip strength of 299 healthy adult males, representing college students newly enrolled in a body conditioning class, college athletes, recruit policemen and policemen. Analysis of the data showed that for men in condition and within the limits of the study, grip strength is significantly related to weight but not to height or age.