Injury to the anterior cruciate ligament (ACL) may have consequences for an athlete in the form of pain, decreased activity levels and early-onset osteoarthritis. Female athletes are at increased risk of injury, perhaps because of differences in neuromuscular function. Methods of identifying risk factors and effective prevention strategies for ACL injury have traditionally involved athletes of high school age or older. However by that age, the opportune time to intervene may have passed. This thesis involves a sequence of studies which measures the neuromuscular function of younger athletes, aged 10-14 years. First, the reliability of measuring strength and power of the lower extremity on an isokinetic dynamometer was explored. Torque and power of the hip flexors and knee extensors were the only measures with acceptable reliability. Conversely, peak velocity of all the tested hip and knee movements demonstrated acceptable reliability. A high amount of variability was found with all test movements, and so alternate tests should be used if measuring an individual athlete’s ability. From the data collected within the reliability study, a sex comparison was undertaken to determine if neuromuscular power differed at this young age. It was determined that girls and boys between 10 and 14 years of age do not differ in terms of knee or hip movement velocity or power. There is evidence to suggest that sex differences exist by adulthood; further research is required to determine when the disparity becomes apparent. The final project was to determine whether strength training would improve the manner in which young female athletes land from a jump; a common ACL injury mechanism. This randomized controlled trial found no difference between the intervention group who trained their legs, and the control group who trained their arms. However those athletes with the poorest landings appeared to improve their movement pattern regardless of training regime. This thesis contributes to the literature by providing evidence for measurement protocols for young athletes, introducing neuromuscular power instead of strength into the investigation of contributing factors to injury, and by furthering the examination of strength training as an effective component of prevention programs.

The purpose was to determine the velocity during strength and power training, with elastic resistance bands, in older adults. Nine older patients, who attended the day hospital rehabilitation program at Riverview Health Centre, were trained for power and strength of the ankle muscles using elastic resistance bands for 4 to 6 weeks. Training sessions were filmed to assess the velocity of training using Proanalyst software. Power training occurred at faster peak velocities as compared to strength training (p<0.001) for both muscle groups, however there were significant differences for average velocity only during training of plantar flexors (p<0.001). There was no significant difference between strength and power training in terms of within individual variability. However, a wide variability was observed between subjects in velocities they trained at and overlap was found between velocities for strength and power training. Hence, researchers should monitor velocity during different types of training in older adults.

Introduction: Creatine is a nitrogen-containing compound that is found in many supplements that claim to increase muscle mass and there is increasing evidence that creatine supplementation can increase muscle mass in older individuals. Purpose: To evaluate the safety of 12-months creatine supplementation and resistance exercise in older adults by monitoring measures of kidney and liver function, complete blood count, and reports of adverse events. Methods: Older adults (n=70, males 50 years of age or older (39), and post-menopausal females (31) who were not performing resistance exercise were recruited for the study and randomized by computer to creatine (32; 18 males, 14 females) or placebo (38; 21 males, 17 females) groups. Other exclusionary criteria were: presence/history or kidney impairments, consumption of creatine supplement/bone altering drugs, and the presence of fragility fractures. Participants were given creatine or placebo (0.1g/kg/day) consumed before and after resistance training on exercise days and with a meal on non-exercise days. The study used a double-blind, placebo-controlled design. Blood and urine were collected to assess complete blood cell count, liver function indicators (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and Bilirubin), and creatinine clearance (kidney function) at baseline, 4 months, 8 months, and 12 months. A mixed ANOVA was used to determine differences in the kidney and liver measures within and between groups, and chi-square analysis was used to determine if the frequency counts for liver, kidney, and other adverse events were different between groups.

BACKGROUND Chronic pain is a common condition in children with juvenile idiopathic arthritis (JIA), affecting their ability to participate in physical activity, a necessary and integral part of a child’s growth and maturation. Resistance training specifically displays a paucity of research in children with JIA, and could potentially be a beneficial form of exercise training for this population. The purpose of this study was to determine the safety, feasibility, and effects of a six week resistance training program on pain in children with JIA. METHODS Seven JIA patients (8-18 years) participated in a home-based, three days per week exercise training program. Pain was measured using an electronic pain diary (PinGo©) for Android tablets. Participants answered questions initially a week prior to training, once a day on non-exercise days and three times a day (before exercise, after exercise, and end of day) on exercise days for a total of seven weeks. Secondary outcome measures included muscle size, muscle strength, and functional ability, measured at baseline and following the 6 week exercise program. Statistical analyses included attaining the average number of exercise sessions completed, pain changes over the seven weeks (averaged over the initial week and then biweekly) via repeated measures ANOVA, dependent t tests between before and after exercise pain intensity and affect, and dependent t tests between secondary outcomes. RESULTS Seven participants completed an average of 13.0 ± 3.6 exercise sessions out of a possible 18. The repeated measures ANOVA revealed no significant differences between pain scores over the seven weeks within each individual (p>0.05). When all participants were pooled dependent t tests before and after exercise showed no differences in pain intensity or pain affect (p>0.05). Secondary measures revealed a significant difference between vastus lateralis thickness before compared to after training (p<0.05). CONCLUSIONS The results of this study suggest that a 6 week home-based resistance training program was tolerable in children with JIA and did not cause a clinically significant increase in pain or any other adverse events. The uniqueness of this exercise program was that it was home-based, allowing children to undertake this emerging form of healthcare within their home environment. As well, the training program was able to significantly improve aspects of fitness in this population. Further research of resistance training in children with JIA is necessary to attain definitive results of its effects and optimal levels of resistance exercise in this population.

The purpose of this study was to compare the effects of intra-set rest intervals (ALT) and traditional resistance (STD) training in hypertrophic resistance training. 22 males (25 +/- 5yrs, 179.71 +/- 5.0cm, 82.1 +/- 10.6kg, 13.6 +/- 4.3% fat, 6.5 +/- 4.5yrs training) were matched according to baseline characteristics and randomly assigned to a STD or ALT 12 week hypertrophic training protocol. Body composition, strength (1RM bench and squat); power (60% 1RM bench and squat); and vertical jump were assessed at baseline, 4, 8, and 12 weeks. Muscle biopsy for myosin heavy chain (MHC) was performed pre and post training. A 2 x 4 (Group x Time) ANOVA was used to assess changes in body composition. A 2 x 4 (Group x Time) ANCOVA covaried by baseline performance measures was used to assess differences in strength and power characteristics. A 2 x 2 (Group x Time) ANCOVA covaried for baseline percentage MHC was used to determine differences pre and post training. Both groups experienced increases in FFM with no differences between groups (62.6 +/- 7.9, 63.4 +/- 7.6, 64.2 +/- 7.4, 64.2 +/- 7.5kg; p>0.05). No time effects were noted in percent fat (13.6 +/- 4.3, 14.1 +/- 4.7, 14.0 +/- 4.6, 14.3 +/- 4.6%fat; p>0.05). Increase in FFM was associated with a decrease in MHCIIX, (ALT, -37.9 +/- 24.1%; STD, -23.4 +/- 23.8%; p = 0.001) and an increase in MHCIIA (ALT, 32.0 +/- 28.8%; STD, 25.4 +/- 29.1%; p = 0.001) with no difference between groups. A significant interaction was observed with the ALT group experiencing greater gains in both 1RM bench (STD 104.1 +/- 27.6, 102.7 +/- 29.0, 107.0 +/- 25.3, 113.2 +/- 27.3; ALT 110.9 +/- 20.1, 117.5 +/- 23.7, 120.8 +/- 22.6, 126 +/- 22.8; p<0.05) and 1RM squat (STD 123.3 +/- 39.3, 139.6 +/- 38.8, 160.2 +/- 36.1, 171.8 +/- 34.5; ALT 130.1 +/- 25.1, 152.6 +/- 24.8, 179.8 +/- 24.5, 193.9 +/- 24.2kg; p<0.05). The ALT group experienced greater gains in power in both the bench (STD 560 +/- 122, 541 +/- 105, 572 +/- 122, 593 +/- 135W; ALT 575 +/- 102, 586 +/- 123, 646 +/- 103, 658 +/- 113W; p<0.05) and vertical jump (STD 1378 +/- 237, 1418 +/- 214, 1452 +/- 210, 1470 +/- 215W; ALT 1389 +/- 179, 1434 +/- 152, 1470 +/- 149, 1537 +/- 150W;p<0.05), with gains in squat power approaching significance (STD 625 +/- 245, 704 +/- 233, 723 +/- 227, 830 +/- 232W; ALT 632 +/- 171, 734 +/- 179, 783 +/- 188, 914 +/- 207W; p<0.10). The use of intra-set rest intervals in programs designed to elicit hypertrophy results in greater gains in strength and power with no significant difference in lean mass or MHC composition after a 12 week resistance training program designed to elicit hypertrophy.

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Bakgrund Styrketräning har många positiva hälsoaspekter, dock är skador vanligt förekommande. Det har inte gjorts någon tidigare forskning där man jämfört skadeprevalensen vid styrketräning på egen hand i gym och vid bodypump, två styrketräningsformer som utförs på lite olika sätt, men båda med fokus på styrka.   Syftet var att undersöka om det fanns skillnader gällande skadeprevalens och typ av skada mellan styrketräning på egen hand i gym och bodypump och om det fanns några skillnader hos män respektive hos kvinnor gällande de två träningsformerna. Studien ämnade även att undersöka och beskriva vilka faktorer som verkade ha orsakat skada vid egen styrketräning i gym och vid bodypump.   Metod Studien hade en deskriptiv och komparativ design. Totalt 60 personer från SATS Sofo deltog i undersökningen, 30 personer som tränade styrketräning på egen hand i gym och 30 personer som tränade bodypump. Data samlades in genom att deltagarna fick svara på en egenkonstruerad enkät med frågor rörande deras träning och eventuell skada och orsak till skada.   Resultat Skillnad i skadeprevalens sågs mellan styrketräning på egen hand i gym och bodypump, p=0,01. Däremot sågs inga skillnader i skadeprevalens hos männen (p=0,09) respektive hos kvinnorna (p=0,06) mellan de två träningsformerna. Det fanns heller inga skillnader gällande skadetyp mellan de två träningsformerna (p=1), inte heller hos män (p=1) eller hos kvinnor (p=1).   Slutsats Det är lägre risk att skada sig vid bodypump än vid styrketräning på egen hand i gym. Fler och större studier behöver göras för att kunna göra några större generaliseringar angående typ av skada, orsak och könsskillnader. / Background Strength training has many positive health aspects, however, injuries are common. There has been no previous research comparing the injury prevalence of strength training on your own in the gym and at bodypump, two strength training exercise performed in slightly different ways, but both focusing on strength.   The aim was to investigate whether there were differences regarding injury prevalence, type of injury between strength training on your own in the gym and bodypump and if there were any differences between men and between women, respectively. The study also aimed at investigating and describing the factors that seemed to have caused injuries in strength training on your own in the gym and at bodypump.   Method The study had a descriptive and comparative design. A total of 60 people from SATS Sofo participated in the survey, 30 people who did strength training on their own in the gym and 30 people participating in bodypump. Data was collected by respondents to a self-designed questionnaire with questions about their training and possible injury and cause of injury.   Results Differences in injury prevalence were seen between strength training on your own in gym and bodypump, p=0,01. On the other hand, no differences were observed regarding men’s injury prevalence (p=0,09) and in women (p=0,06) respectively, between the two types of exercise. There were also no differences regarding the type of injury between the two types of exercise (p=1), nor in men (p=1) or in women (p=1).   Conclusion There is less risk for injuries at bodypump than at strength training on your own in the gym. More and larger studies are needed to be able to generalize the type of injury, cause and gender differences.

Orientador: Sebastião Gobbi / Banca: Mara Patricia T. Chacon Mikahil / Banca: Vilmar Baldissera / Resumo: Esta dissertação explorou por meio de dois estudos o efeito de diferentes intervalos de recuperação (IR) entre as séries do treinamento com pesos (TP) nas respostas: 1) neuromusculares agudas [número de repetições (NR) por séries, sustentabilidade das repetições entre as séries, volume total, contração voluntária máxima (CVM) e atividade eletromiográfica (atividade EMG)] e crônicas [da CVM, taxa de desenvolvimento de força pico (TDFP) e cargas absolutas de 15 repetições máximas (15 RM)]; 2) agudas das concentrações do hormônio do crescimento (GH). O primeiro estudo foi concluído com 21 participantes (66,4 +- 4,4 anos) e o segundo com 19 participantes (66,1+- 4,3 anos). Inicialmente todas as participantes realizaram duas sessões de familiarização aos procedimentos de avaliação da curva força-tempo isométrica (Cf-t isométrica) e três sessões para determinação das cargas referentes a 15 RM no exercício leg-press. Nas três visitas subseqüentes, foram realizadas duas sessões de teste adotando-se IR entre as séries de um (IR-1) e três (IR-3) minutos e uma sessão controle. Nas sessões de teste, as participantes realizaram três séries até a fadiga muscular com a carga de 15 RM e avaliações da curva força-tempo isométrica (Cf-t isométrica) e da atividade EMG pré e cinco minutos pós-sessões de teste. Na sessão controle, as participantes realizaram as mensurações da Cf-t isométrica e da atividade EMG pré e após permanecerem em repouso por 15 minutos. Após as coletas iniciais, as participantes foram separadas aleatoriamente em dois grupos: um treinou com IR de um minuto (G-1 min) entre todas as séries e o outro com três minutos (G-3 min). Ambos os grupos realizaram oito semanas de TP com as seguintes características: a) três sessões semanais; b) oito exercícios; c) intensidade relativa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This dissertation explored through two studies the effect of different rest intervals (RI) between sets of resistance training (RT) in the responses: 1) acute neuromuscular [number of repetitions (NR) in sets, sustainability of repetitions between sets, total volume, maximal voluntary contraction (MVC) and electromyography activity (EMG activity)] and chronic [MVC, rate of force development peak (RFDP) and absolute loads of 15 repetitions maximum (15 RM)]; 2) acute concentrations of growth hormone (GH). The first study was completed with 21 participants (66.4 +- 4.4 years) and the second with 19 participants (66.1 +- 4.3 years). Initially, all participants performed two familiarization sessions to procedures of the isometric force-time curve (Cf-t isométrica) and three sessions to determine the load corresponding to 15 RM in the exercise leg-press. In three subsequent visits, there were performed two test sessions adopting IR between sets of one (RI-1) and three (RI-3) minutes and one control session. In test sessions, the participants performed three sets to muscular fatigue with the load of 15 RM and evaluations of Cf-t isometric and EMG activity pre and five minutes post-test session. In the control session, the participants performed measurements of Cf-t isometric and EMG activity before and after remaining at rest for 15 minutes. After the initial collection, participants were divided randomly into two groups: one trained with one minute (G-1 min) between all sets and the other with three minutes (G-3 min). Both groups performed eight weeks of RT with the following characteristics: a) three times a week b) eight exercises; c) relative intensity adjusted so that muscular fatigue occurred in 15 RM in the last set. At the end of eight weeks of RT, the participants were retest again... (Complete abstract click electronic access below) / Mestre

Bodybuilding is a weight training sport similar to powerlifting, strongman, and Olympic weightlifting. Instead of performing a feat of strength in competition, the athletes are based on physical appearance. Information about injuries within the other sports are available. However, there are a low number of studies on competitive bodybuilding. The purpose of this study was to investigate the prevalence and localization of injuries and pain in Swedish bodybuilding athletes. Additional aims were to investigate sex differences and the significance of explanatory variables. Data from 83 male and 105 female active bodybuilding athletes were collected using a web-based questionnaire. Athletes active within all of the available bodybuilding categories were included. The subjects were recruited through flyers in local gyms in Sweden and ads on social media. Fifty-eight percent (109/188) of the athletes reported current pain during training and 74.5 % (140/188) have been injured at least once during their competitive career. The rate of injury was calculated as 0.27 injuries per athlete per year. There were 0.42 injuries per 1000h of exercise. Injuries in competitive bodybuilding are less common compared to other weight training sports. In agreement with earlier studies, the most prevalent anatomical localizations of injury were the shoulders, lower back/buttocks, and knees. There were no notable differences in sex regarding injury localizations. Age, training frequency, calorie intake and medical care were associated with having an injury

Aim. The purpose of this study was to evaluate the relationship between weightlifting performance (snatch, clean and jerk, and total) and variables obtained from the isometric mid-thigh pull (IMTP). Methods. Twelve weightlifters, ranging from novice to advanced, performed the IMTP 10 days after a competition. Correlations were used to evaluate relationships between variables of the IMTP and absolute and scaled competition results. Results. Unsealed competition results correlated strongly with IRFD (0-200ms: r=0.567-0.645, 0-250ms: r=0.722-0.781) while results correlated weakly with Peak IRFD (5ms window, r=0.360-0.426). Absolute peak force values correlated very strongly with absolute values for the competition performance (r=0.830-0.838). Force at 100ms, 150ms, 200ms and 250ms also correlated strongly with competition results (r=0.643-0.647, r=0.605-0.636, r=0.714-0.732, r=0.801-0.804). Similar findings were noted for allometrically scaled values. Conclusion. Measures of average IRFD probably represent a more relevant variable to dynamic performance than does Peak IRFD (5ms). Maximum isometric strength also is likely to have a strong role in weightlifting performance.