International SportMed Journal - Volume 14, Issue 3, 2013
Volume 14, Issue 3, 2013
The effect of an eight week proprioception training programme on knee joint proprioception in taekwondo athletes : original research articleSource: International SportMed Journal 14, pp 99 –102 (2013)More Less
Background : A regular proprioception training programme leads to significant improvement in the proprioceptive ability of athletes.
Research subject : The purpose of this study was to investigate the suitability of the knee joint proprioception for active taekwondo athletes and to examine the effects of an eight-week training proprioception programme on knee joint proprioception.
Type of study : Randomised controlled trial.
Methods : A total of 42 healthy taekwondo athletes participated in this study voluntarily. They were randomly divided into two groups: An experimental group of males (N=13) and females (N=13) undertaking a proprioception training programme and a control group of males (N=8) and females (N=8) who did not undertake the proprioception training programme during the eight-week period. The proprioception training programme was applied to the subjects three days per week for eight weeks. The measurement of the proprioception of subjects was taken using the Multi-joint System Biodex System 3 Pro isokinetic testing. Knee joint proprioception was evaluated twice: before and after the proprioception training programme.
Results : After the eight-week proprioception training programme, significant differences were observed in both the dominant (differences of mean 1.76±0.41 for 30° and 2.83±1.52 for 70° in female; 1.86±0.66 for 30° and 2.96±2.4 for 70° in male) and non-dominant (differences of mean 1.99±1.4 for 30° and 2.94±1.16 for 70° in female; 1.67±0.64 for 30° and 4.44±2.89 for 70° in male) knee joint proprioception scores in the experimental group (p < 0.05). It was concluded that the control group did not show any significant differences in either the dominant or non-dominant knee joint (30° and 70°) proprioception scores (p > 0.05).
Conclusion : The proprioception training programme improved knee joint proprioception based on the detection of positional sense for female and male taekwondo athletes.
Age-related responses among adult males to a 14 day high intensity exercise-heat acclimation protocol : original research articleSource: International SportMed Journal 14, pp 103 –118 (2013)More Less
Background : The influence of age on heat acclimation responses among aerobically fit males across a 14 day high intensity running protocol was assessed.
Research question : Will young and middle-aged males with similar VO2max, weekly running distance and body composition respond similarly to continuous, high intensity exercise-heat acclimation?
Hypothesis : Young and middle-aged males would respond similarly and fully acclimate within 14 days.
Study type : Non-randomised comparative.
Methods : 9 young (20.4 ± 2.4 years; 57.1 ± 3.8 ml·kg-1·min-1), 7 middle-aged (44.6 ± 4.5 years; 55.2 ± 6.3 ml·kg-1·min-1 pre-acclimation) male runners participated.
Protocol : 30 minute runs daily at 75% VO2max in a hot, moderately humid (35°C, 35% RH) environment.
Outcome measures : resting plasma volume % change (PV), rectal temperature (Tre), heart rate (HR), sweat loss (SL), perceived exertion (RPE).
Results : Tre, HR and RPE decreased, while PV (3.3 ± 5.6% young, 2.8 ± 3.3% middle-aged) increased within both groups (p < 0.050). SL did not change within either group. Groups differed in HR, but demonstrated similar Tre, PV, RPE and SL. Pre- and post-acclimation VO2max did not differ within or between groups.
Conclusions : Young and middle-aged, aerobically fit males responded similarly to high intensity exercise-heat acclimation. Both groups appeared to fully acclimate, although they may have experienced a latent HR response. The similar responses suggest that aging-related biological changes do not impair aerobically fit males' thermoregulation through their mid-40s during high intensity, hot weather exercise.
The comparative use of the Bleep or Yo-Yo test in high-level British female basketball players : original research articleAuthor Jose M. Gonzalez-RaveSource: International SportMed Journal 14, pp 119 –126 (2013)More Less
Objectives : The aims of this study were to perform the 20-meter shuttle run test (Bleep test) and the Yo-Yo test in two high level British female basketball teams, and to evaluate and compare both tests between themselves.
Methods : 14 elite level female basketball players from a top-4 team competing in the England Basketball League Division I and 15 female basketball players from the Under 20 Great Britain National Team (U20 GB) playing in the European Championship voluntarily participated in this study. The anthropometry tests performed were weight, height and BMI. Each team performed the Bleep test and the Yo-Yo Test on two separate and non-consecutive days (with a lapse of 48 hours between the two tests), at the same time (10 am) and in the same gym hall with wooden floor.
Results : Statistical differences were found between the VO2max values of the two teams obtained in the 20-meter shuttle run (p=0.000), and between the VO2max calculated by Yo-Yo IR1 and the VO2max calculated by 20-meter shuttle run without taking into account the age (p=0.002).
Conclusions : British basketball players showed cardiorespiratory levels (VO2max) lower than high-level female basketball players from countries where basketball is more popular and better developed. In addition, it was proved that there are no differences when it comes to the use of the Bleep test or the Yo-Yo test in order to calculate the maximum oxygen uptake through an indirect method.
Effects of the playing formation and game format on heart rate, rate of perceived exertion, vertical jump, individual and collective performance indicators in youth basketball training : original research articleSource: International SportMed Journal 14, pp 127 –138 (2013)More Less
The purpose of this study was to examine the effects of playing formation (with or without a post player) and the game format (3x3 or 5x5) on heart rate (HR), rate of perceived exertion (RPE), vertical jump, as well as individual and collective performance indicators in basketball. We analyzed ten male basketball players (age: M = 13.3, S.D = 0.71 years, mass: M = 49.0, S.D = 3.8 kg, and height: M = 160.9, S.D = 9.1 cm) in game situations, which were organized into four periods of four minutes and interspersed with two minutes of active recovery. HR was measured continuously, analyzed by time spent and then placed into four zones according to the %HRmax (Zone 1: <75%; Zone 2: 75%-84.9%; Zone 3: 85%-89.9%; zone 4: ≥90%). The 3x3 game format elicited higher HR and RPE. These players spent more time performing over 90% of the HRmax than the two 5x5 game formats and thus elicited, in general, higher frequencies of individual performance indicators (p <.01). The vertical jump results (squat and countermovement jump) were higher in post-game periods (p<.05) and the results of the collective performance indicators did not reveal a clear tendency, which benefited one game over the others. Also, when playing in 5x5 game format with a post player, the teams obtained higher values in offensive efficacy. Overall, these results suggest that the use of 3x3 game format leads to a greater intensity in training and thus required the highest number of individual performance indicators from the players.
The influence of match frequency on the risk of injury in professional soccer : original research articleSource: International SportMed Journal 14, pp 139 –147 (2013)More Less
Background : To the best of these authors' knowledge, no previous study of professional soccer players playing different match frequencies has been conducted to investigate the risk of injury at the highest club competitive level in South America.
Research question : To analyse the risk of injury in professional soccer players involved in two tournaments with different match frequencies.
Type of study : Prospective cohort study.
Method : A total of 95 professional players from several Argentinian teams were included. Forty players were involved only in the National Championship (Low Match Frequency, LMF) and 55 players took part in both tournaments: the National Championship and the Libertadores Cup (High Match Frequency, HMF). Exposure to football and injury incidence, severity and distribution were compared between LMF and HMF players.
Results : HMF players had greater exposure to matches (18.6 vs. 14 matches per season p<0.01), whereas exposure to training did not differ. There was a higher risk of injury during training (4.5 vs. 1.2 /1000 h, p<0.01) and total exposure (8.9 vs. 5.0 /1000 h, p<0.01) in HMF players than in LMF players, whereas no difference was observed with respect to matches played. After an injury, HMF players had longer absences from matches played (3.5 vs. 1 match, p<0.01), training (14.4 vs. 6.8 days, p<0.01) and total exposure (21.7 vs. 9.4 days, p<0.01). The most prevalent diagnoses were muscular and tendon injuries more frequently observed in HMF players (55.4 % vs. 44.8 %, p<0.05).
Conclusions : Professional soccer players involved in two tournaments are exposed to a higher risk of injury. This phenomenon would have a greater influence on training sessions than on matches played.
Source: International SportMed Journal 14, pp 148 –154 (2013)More Less
Background : Overuse osteopathy including stress fracture is a serious problem for female runners.
Research question : The purpose of this study was to investigate the bone metabolism markers in female collegiate track and field athletes with/without overuse osteopathy and sedentary control.
Type of study :Cross-sectional study.
Methods : Subjects included 25 female collegiate track and field athletes (stress fracture subjects, n = 12, no-stress fracture subjects, n = 13). In addition, 16 women without exercise experience were included as a control group. The measured elements were bone strength by quantitative ultrasounds (QUS), bone metabolism markers (serum bone-specific alkaline phosphatase [BAP], circulating serum cross-linked N-telopeptide [NTx], urinary NTx, and tartrate-resistant acid phosphatase [TRAP]-5b), and estradiol.
Results : In the the resulting analysis, both stress fracture and no-stress fracture groups showed significantly higher QUS values than the non-exercising control group (p < 0.001). Moreover, both athlete groups exhibited significantly higher TRAP-5b levels than the control group (p < 0.05). However, BAP, blood NTx, urinary NTx, and estradiol levels showed no significant differences between the three groups.
Conclusion : These findings suggest that TRAP-5b is a useful marker to monitor bone metabolism in the track and field athletes.
Enhanced femoral neck strength in response to weightlifting exercise training in maturing male rats : original research articleAuthors: Lucas Rios Drummond, Ricardo Junqueira Del Carlo, Karina Ana Da Silva, Aurora Correa Rodrigues, Pedro Natali Pinheiro Soares, Thales Nicolau Primola Gomes, Antonio Jose Natali, Stephano Freitas Soares Melo, Edilamar Menezes De Oliveira, Miguel Araujo Carneiro-Junior and Mario Jefferson Quirino LousadaSource: International SportMed Journal 14, pp 155 –167 (2013)More Less
Background : While the reduction of bone collagen content has been suggested to occur in bone loss during aging, the effects of weightlifting exercises on femoral neck strength and collagen content are not completely understood.
Research question : This study tested the effects of weightlifting exercise training on femoral neck mechanical and structural properties in maturing rats.
Type of study : Randomised controlled study.
Methods : Twelve-week-old male Wistar rats (initial body mass, 252 ± 14 g) were randomly divided into Control (CO, n = 7) and Trained (TR, n = 7) groups. Animals from the TR group were subjected to a resistance-training regime [five sessions·wk-1; four sets of 12 repetitions, 80% of one repetition maximum (1 RM), 90 s resting interval] for eight weeks. The femoral neck maximum load, stiffness and tenacity were measured. Bone mineral density (BMD) and mineral content (BMC), as well as the femoral neck bone volume (BV/TV) and collagen type I and III content were assessed.
Results : TR animals exhibited a higher (P < 0.05) femoral neck maximum load (117 ± 18 N vs. 99 ± 17 N), stiffness (151 ± 18 N/mm vs. 116 ± 17 N/mm), tenacity (67 ± 12 mJ vs. 61 ± 13 mJ), total collagen (32.83 ± 3.59% vs. 24.73 ± 5.89%) and collagen type III content (6.5 ± 4.1% vs. 0.6 ± 0.7%) than CO animals, respectively. No effects of exercise were observed on BV/TV, BMC, BMD and collagen type I content (P > 0.05).
Conclusion : Weightlifting exercise training enhances the femoral neck mechanical properties in maturing rats without increasing bone volume and mineral density, but with important augmentations in the total and type III collagen contents. This indicates that the improved femoral neck strength in response to weightlifting training is more likely to be due to bone quality as opposed to bone quantity.
Factors which influence return to sport following anterior cruciate ligament (ACL) reconstruction surgery : a narrative review : review articleSource: International SportMed Journal 14, pp 168 –184 (2013)More Less
Objectives : To provide an evidence-based narrative review in accordance with the PRISMA guidelines of return to pre-injury sport levels following ACL reconstruction surgery.
Data sources : Databases including: Pubmed, MEDLINE, Embase, CINAHL, Web of Science and Google Scholar were searched. Various combinations of the following keywords; 'ACL reconstruction', 'ACL surgery', 'sports', 'sports activity', and 'return to sports participation', were used in the searches.
Study selection : Thirty-one studies were identified and included in this review. All studies documented a specific return to sport percentage after ACL reconstruction or reported a mean preoperative and postoperative activity score.
Data extraction : Return-to-sport rates (RTS) following ACL reconstruction surgery and factors influencing these outcomes including: operative style, acute versus chronic ACL deficiency, prehabilitation/rehabilitation programmes, psychological factors, age/gender and competitive/elite athletes were compared between studies.
Data synthesis : RTS ranged from 20% to 100% depending on the cohort and sporting discipline. There was no leading graft choice or surgical technique that provided better RTS, however early reconstruction and early-return to sports had superior outcomes than late reconstruction and late-return to sports. There was some evidence to suggest that psychological status six months postoperatively could be crucial in terms of RTS. Higher RTS were observed in males and younger patients while the majority of professional athletes returned to pre-injury levels despite abnormal knee function.
Conclusion : Return to pre-injury levels of sport following ACL reconstruction is multifactorial. To establish accurate return to pre-injury sport rates, future studies need to document pre-injury activity levels in addition to preoperative activity levels.