Free weights are generally preferred over machines by practitioners of strength training because they involve incorporation of greater muscle mass because of the greater stabilization that is required. Using free weights may therefore allow one to gain more muscle mass and strength with chronic training; however, this has not been thoroughly addressed. The purpose of this study was to compare the effect of training with free weights or machines on muscle mass, testosterone and cortisol concentrations, and strength. Fifteen males and twenty-one females aged 22 ± 3 y with previous weight training experience trained using only free weights or only machines for eight weeks. Hormone concentrations were assessed via saliva samples pre and post workout at the beginning, mid-way, and end of the study. Muscle thickness, lean tissue mass, and strength were measured at the beginning and the end of the study. Elbow flexor thickness increased significantly by 3.9% and a 5.1% in the free weight group and machine group, respectively (p<0.01), with no difference between groups. Knee extensor thickness increased significantly by 4.6% and a 4.9% in the free weight group and machine group, respectively (p<0.01), with no difference between groups. No significant changes occurred in the lean tissue mass during the eight week training period. The group x time interaction for machine bench press strength was close to significance (p=0.054) with the machine training group experiencing a greater increase in strength compared to the free weight training group (13.9% vs. 8.6%). Free weight bench press, free weight squat, and Smith machine squat strength increased significantly in both groups (11-19%; p<0.01) with no difference between groups. The males in the free-weight group had a 21.7% increase in testosterone from before to after acute training sessions (p<0.01); however, the acute increase in testosterone to cortisol ratio in males training with free weights did not differ from males training on machines. Results from this study indicate that training with free weights or machines result in similar increases in muscle mass and strength, and testosterone to cortisol ratio. Males training with free weights may benefit from a greater acute increase in testosterone levels during individual training sessions.

Free weights are generally preferred over machines by practitioners of strength training because they involve incorporation of greater muscle mass because of the greater stabilization that is required. Using free weights may therefore allow one to gain more muscle mass and strength with chronic training; however, this has not been thoroughly addressed. The purpose of this study was to compare the effect of training with free weights or machines on muscle mass, testosterone and cortisol concentrations, and strength. Fifteen males and twenty-one females aged 22 ± 3 y with previous weight training experience trained using only free weights or only machines for eight weeks. Hormone concentrations were assessed via saliva samples pre and post workout at the beginning, mid-way, and end of the study. Muscle thickness, lean tissue mass, and strength were measured at the beginning and the end of the study. Elbow flexor thickness increased significantly by 3.9% and a 5.1% in the free weight group and machine group, respectively (p<0.01), with no difference between groups. Knee extensor thickness increased significantly by 4.6% and a 4.9% in the free weight group and machine group, respectively (p<0.01), with no difference between groups. No significant changes occurred in the lean tissue mass during the eight week training period. The group x time interaction for machine bench press strength was close to significance (p=0.054) with the machine training group experiencing a greater increase in strength compared to the free weight training group (13.9% vs. 8.6%). Free weight bench press, free weight squat, and Smith machine squat strength increased significantly in both groups (11-19%; p<0.01) with no difference between groups. The males in the free-weight group had a 21.7% increase in testosterone from before to after acute training sessions (p<0.01); however, the acute increase in testosterone to cortisol ratio in males training with free weights did not differ from males training on machines. Results from this study indicate that training with free weights or machines result in similar increases in muscle mass and strength, and testosterone to cortisol ratio. Males training with free weights may benefit from a greater acute increase in testosterone levels during individual training sessions.

Research has shown the combination of strength training and motor imagery can increase isometric force production. This study explored the impact of motor imagery on dynamic strength using a 3RM bench press and back squat. Participants were randomized into either the treatment or placebo condition and engaged in an11 week training program (motor imagery: n=8; motivational music: n=7). Results for both the upper and lower body strength showed a significant overall main effect for time from baseline to post-test measure (upper body: motor imagery: M= 43.5 kg, SD= 18.65 kg to M= 60.7 kg, SD= 24.0 kg; placebo: M= 45.0 kg, SD= 15.54 kg to M=55.0 kg, SD=17.9 kg; p=.000) (lower body: motor imagery: M= 82.9 kg, SD= 29.72 kg to M=110.0 kg, SD= 23.4 kg; placebo: M= 84.6 kg, SD= 20.29 kg to M=119.3 kg, SD= 24.6 kg; p=.000). The upper body strength displayed a significant interaction effect (p=.001) between program type and time, lower body strength had an insignificant interaction effect (p=.162, ?p2=.162). Finally, there was no between group significant difference for overall main of upper (p=.870, ?p2=.002) and lower body (p=.818, ?p2=.004) strength. These results suggest that motor imagery may have an impact on the development of strength over an 11 week training program. However, further understanding of imagery use and how it impacts strength is needed.

In 2011, the U.S. Bureau of Labor Statistics documented injury rates of musculoskeletal injuries requiring days away from work in the full-time firefighter work force at approximately 185/10,000 employees. This represents a staggering cost to municipalities in overtime salaries as well as departmental readiness to meet community needs. We propose, in year one of the project, to observationally determine the prospective association between physical performance measures at baseline and risk of future musculoskeletal injury in a cohort of municipal firefighters of the Austin Fire Department (AFD). We will implement an injury registry surveillance system as well as utilize the AFD Wellness Center physical fitness evaluation of all firefighters within AFD. The prospective association between changes in physical performance measures and risk of musculoskeletal injury within a cohort of AFD firefighters will allow determination of risk of occupational injury incidence and injury severity. To study the effect of musculoskeletal training on lowering the risk of occupationally-related injury, we will conduct a randomized cluster cross-over trial. The critical intervention will be a strength training intervention of six months duration, implemented in Year 2. There are a total of 43 fire stations in the AFD. We will randomize 50% of the fire stations in a strength training intervention for six months with the remaining 50% of fire station participating for the second six months. Changes in fitness, strength, and incidence of injury will be monitored for the 12 months of this design. Results from this study will be disseminated to firefighting agencies with strategies for occupationally-related musculoskeletal injury prevention. / text

No description available.

Introduction: The present study describes a 3 year model for physical training of young female football players. The aim was to investigate and describe how systematical training based upon The Spinal Engine Theory and periodisation of training over time could increase the players’ physical statues, hence prepare them for increased loading over time associated with elite football. Method: 12 out of 28 players completed 3 years of periodised training including annual plans of preparatory, competitive and transition phases. A testbattery including flexibility, stability, maximum strength and power tests was performed annually. Results: A significant increase in both maximum strength and power over time was visible using ANOVA within subjects tests. Post Hoc tests indicated that the change was visible after only one year and the trend continued. Discussion: The results and the model can aid future discussion regarding coaching education and loading of young players. Along with further research regarding psychological aspects as well the material can serve as a basis for how clubs can create a better support structure around our young players. / Den aktuella studien beskriver en 3 årig modell för fysisk träning av unga kvinnliga fotbollsspelare. Syftet var att undersöka och beskriva hur systematisk träning baserad på The Spinal Motor Theory och periodisering av träning över tid skulle kunna öka spelarnas fysiska status, därmed bättre förbereda dem för ökad belastning över tid och förbereda dem för kommande elitfotboll. 12 av 28 spelare genomgick hela 3 åriga modellen som inkluderade årlig periodiserad träning innehållande förberedande, tävling och övergångsfaser. Ett testbatteri som inkluderade flexibilitet, stabilitet, maxstyrka och power tester utfördes årligen. En betydande ökning av både maximal styrka och power över tiden var synlig vid analys av ANOVA (within-subject) tester. Post hoc tester visade att förändringen var synlig efter bara ett år och trenden fortsatte under kommande 2 år. Resultaten kan bidra till framtida diskussioner kring tränarutbildning och riktlinjer kring belastning av unga spelare. Tillsammans med vidare forksning kring psykologiska aspekter kan materialet ses som ett underlag för hur klubbar kan arbeta för att skapa en bättre stödstruktur kring våra unga spelare.

Aim: The purpose of the present study was to compare the effects of an 8 week period of combined endurance and resistance training (concurrent training) with that of only endurance training on both maximum strength (1 RM) in the leg press test and performance in the 30 s Anaerobic Wingate Test (WANT) in moderately trained endurance cyclists. Method: Twenty male moderately trained cyclists were recruited for the investigation and were assigned to either an Endurance training group (E; n=10) or an Endurance Resistance training group (ER; n=10).  Subjects underwent 8 weeks (2 training sessions per week, 16 sessions in total) of concurrent training (60 min steady state cycling session followed by 6 sets 12 repetitions of leg press) or cycling only. Furthermore the subjects of the intervention completed both Pre and Post intervention testing in the 1RM leg press and the Wingate 30 s cycle test which was conducted twice (SRM cycle sprint 1 and SRM cycle sprint 2) within each testing session. Results: The results attained from the intervention were that the ER group demonstrated an increase in concentric leg strength within the one repetition maximum (1 RM) leg press test by 18.7 % from pre-test values 339 ± 42 to post test values 402 ± 59 kg. With regard to the Wingate cycle sprints there was significant improvement from pre to post test results in peak power of cycle sprint 1 from 1019 ± 110 watt to 1077 ± 153 watt 5.7 % and cycle sprint 2 from 1001 ± 131 to 1054 ± 161 watt, 5.3 % (P &lt; 0.05) respectively. The E group showed no significant change in l RM or the Wingate cycle sprints after training. Conclusions: The main findings of the study is that an 8-week concurrent training intervention can lead to significant concentric strength gains in 1 RM leg press development and increased peak power within the Wingate 30 s cycle sprint when conducted by moderately trained cyclists.

Cross-education is a neural adaptation defined as the increase in strength or functional performance of the untrained contralateral limb after unilateral training of the opposite homologous limb. Since cross-education can improve strength in an untrained limb, there is therapeutic potential to apply cross-education to clinical rehabilitation settings; however, a large gap in the literature remains. The first objective of this thesis was to determine if cross-education could improve strength and functional performance (i.e. active range of motion (AROM), self-reported function) of an immobilized limb using a shoulder sling model in both healthy and injured participants. The second objective was to determine if cross-education could improve strength and functional performance (i.e. AROM, self-reported function) of wrist fracture rehabilitation after unilateral training of the non-fractured limb. Study 1 applied cross-education to non-injured participants who wore a shoulder sling and swathe and strength trained the non-immobilized limb. Strength (NORM dynamometer), muscle size (ultrasound), electromyography, and interpolated twitch were measured. Results showed cross-education increased strength and maintained muscle size in the immobilized limb after training the non-immobilized limb. Study 2 applied cross-education using a clinically relevant at-home resistance tubing shoulder strength training program to healthy participants. Results showed significant cross-education effects for untrained shoulder external and internal rotation strength (handheld dynamometer), and increased muscle size (ultrasound) in the trained supraspinatus and anterior deltoid. Study 3 applied cross-education using the clinically relevant strength training program (in Study 2) to post-shoulder surgery rehabilitation and measured strength (handheld dynamometer), muscle size (ultrasound), AROM (goniometer), and self-reported function (Western Ontario Rotator Cuff Questionnaire) (WORC). Results showed the training group had significantly greater supraspinatus muscle thickness at 6 months post-surgery compared to the control group; however, there were no cross-education effects for strength, AROM, or the WORC. Study 4 applied cross-education during rehabilitation from wrist fractures and measured strength (handgrip dynamometer), AROM (goniometer), and self-reported function (Patient Rated Wrist Evaluation) (PRWE). Results showed cross-education improved strength and AROM in the fractured limb 12 weeks post-fracture. In conclusion, there was evidence for cross-education to benefit a healthy immobilized limb and to use a clinically relevant shoulder strength training program to produce cross-education effects. When cross-education was applied to shoulder surgeries there were improvements in muscle size but no effect for strength, AROM or function. However, when applied to wrist fractures, strength and AROM were improved for the injured limb. These findings represent the first well-controlled evidence that cross-education may improve rehabilitation after unilateral injuries.

Triathleter och cyklister är uthållighetsidrottare med extrem träningsvolym och stort krav på aerob kapacitet, dock krävs även anaerob- power och muskelstyrka för delmoment som backar och tempoväxlingar. Många uthållighetsidrottare tvekar över att implementera styrketräning i tron att effekten ska påverka deras prestation negativt, dessutom gör den höga träningsvolymen det svårt att kombinera. Styrketräning som komplement till uthållighetsträning har dock visats ge positiv effekt och kan förslagsvis förbättra prestation. Syftet var att undersöka huruvida ett styrketräningspass per vecka kan förbättra anaerob kapacitet hos cyklister och triathleter samt om en eventuellt ökad benstyrka kan påverka simtiden hos triathleter. Metoden var en interventionsstudie med pre- och posttest där deltagarna fick genomföra ett styrketräningspass innehållandes tre övningar, en gång per vecka under 12 veckors tid, som komplement till ordinarie träning. Resultatet vid test av maximal styrka i benpressmaskin påvisade en signifikant ökad benstyrka för interventionsgruppen med p = 0,001, en styrkeförbättring på 16,5 %. Wingate- testet visade signifikant förbättring för maxeffekt, p = 0,003, en förbättring med 11,1 % samt maxeffekt per kilo kroppsvikt, p = 0,001, en förbättring på 11,9 %. För kontrollgruppen sågs inga noterbara förändringar och inget samband kunde heller ses mellan en ökad benstyrka och simprestation.Vår styrketräning i kombination med deras ordinarie träning kan förslagsvis fungera synergiskt och optimera prestationen. / Triathletes and cyclists are endurance athletes with extreme training volume and high demands on aerobic capacity but the sport also requires anaerobic power and muscular strength for example hills or changes in tempo. Many endurance athletes do hesitate to implement strength training with the belief that the effect will negatively affect their performance, the high training volume also makes it difficult to combine. Strength training as a complement to endurance exercise has been shown to have a positive effect and may improve performance. The aim was to investigate whether strength training once a week can improve anaerobic capacity among cyclists and triathletes, and if any potential increase in strength capacity may affect swim performance in triathletes. The method was an interventional study with pre and post-test in which participants had to conduct a workout consisting of the three exercises, once a week for 12 weeks, in addition to regular exercise. The results from the test of maximum strength in the leg press showed a significantly increased strength in the intervention group, p = 0.001, a strength improvement of 16.5%. The Wingate test showed a significant improvement in maximum power, p = 0.003, an improvement of 11.1%, and the maximum power per kilogram bodyweight, p = 0.001, an improvement of 11.9 %. For the control group, there were no noticeable changes and no association was seen between increased strength and swim performance. Our strength training in combination with the regular workout can probably work synergistically and optimize their performance.

Neurological and morphological adaptations are responsible for the increases in strength that occur following the completion of resistance exercise training interventions. There are a number of benefits that can occur as a result of completing resistance exercise training interventions, these include: (i) reduced risk of developing metabolic health issues; (ii) decreased risk and incidence of falling; (iii) improved cardiovascular health; (iv) elevated mobility; (v) enhanced athletic performance; and (vi) injury prevention. Traditional resistance exercise (constant load resistance exercise (CL)) involves equally loaded eccentric and concentric phases, performed in an alternating manner. However, eccentric muscle actions have unique physiological characteristics, namely greater force production capacity and lower energy requirements, compared to concentric actions. These characteristics have led to the exploration of eccentric-focused resistance exercise for the purposes of injury prevention, rehabilitation, and enhancement of functional capacity. Accentuated eccentric load resistance exercise (AEL) is one form of eccentric-focused resistance exercise. This type of resistance exercise involves a heavier absolute external eccentric phase load than during the subsequent concentric portion of a repetition. Existing training study interventions comparing AEL to CL have demonstrated enhancements in concentric, eccentric, and isometric strength with AEL. However, no differences in strength adaptations have been reported in other AEL vs. CL training studies. Only 7 d intensified AEL training interventions have measured neuromuscular variables, providing evidence that enhanced neuromuscular adaptations may occur when AEL is compared to CL. Therefore, a lack of information is currently available regarding how AEL may differentially affect neuromuscular control when compared to CL. Furthermore, the equivocal findings regarding the efficacy of AEL make it difficult for exercise professionals to decide if they should employ AEL with their athletes or patients and during which training phase this type of resistance exercise could be implemented. Therefore, the aims of this thesis were: (i) to examine differences in acute neuromuscular, kinetic, and kinematic responses between AEL and CL during both lower-body single-joint resistance exercise and multiple-joint free weight resistance exercise; (ii) to assess acute force production and contractile characteristics following AEL and CL conditions; (iii) to investigate the influence of eccentric phase velocity (and time under tension) on acute force production and contractile characteristics following AEL and CL conditions; and (iv) to compare common drive and motor unit firing rate responses after single- and multiple-joint AEL and CL. Before investigating neuromuscular, kinetic, and kinematic responses to AEL it was deemed necessary to evaluate normalisation methods for a multiple-joint free weight resistance exercise that would permit the implementation of AEL. Therefore, the aim of the first study of the thesis was to evaluate voluntary maximal (dynamometer- and isometric squat-based) isometric and submaximal dynamic (60%, 70%, and 80% of three repetition maximum) electromyography (EMG) normalisation methods for the back squat resistance exercise. The absolute reliability (limits of agreement and coefficient of variation), relative reliability (intraclass correlation coefficient), and sensitivity of each method was assessed. Strength-trained males completed four testing sessions on separate days, the final three test days were used to evaluate the different normalisation methods. Overall, dynamic normalisation methods demonstrated better absolute reliability and sensitivity for reporting vastus lateralis and biceps femoris EMG compared to maximal isometric methods. Following the methodological study conducted in Chapter 2, the next study began to address the main aims of the thesis. The purpose of the third chapter of the thesis was to compare acute neuromuscular, kinetic, and kinematic responses between single-joint AEL and CL knee extension efforts that included two different eccentric phase velocities. Ten males who were completing recreational resistance exercise attended four experimental test day sessions where knee extension repetitions (AEL or CL) were performed at two different eccentric phase velocities (2 or 4 s). Elevated vastus lateralis eccentric neuromuscular activation was observed in both AEL conditions (p= 0.004, f= 5.73). No differences between conditions were detected for concentric neuromuscular or concentric kinematic variables during knee extension efforts. Similarly, no differences in after-intervention rate of torque development or contractile charactersitics were observed between conditions. To extend the findings of the third chapter of the thesis and provide mechanistic information regarding how AEL may differentially effect acute neuromuscular variables that have been reported to be undergo chronic adaptations, additional measures that were taken before and after the intervention described in the previous chapter were analysed. Therefore, the purpose of the fourth chapter of the thesis was to compare motor unit firing rate and common drive responses following single-joint AEL and CL knee extension efforts during a submaximal isometric knee extension trapezoid force trace effort. In addition, motor unit firing rate reliability during the before-intervention trapezoid force trace efforts was assessed. No differences in the maximum number of detected motor units were observed between conditions. A condition-time-point interaction effect (p= 0.025, f= 3.65) for firing rate in later-recruited motor units occurred, with a decrease in firing rate observed in after-intervention measures in the AEL condition that was completed with a shorter duration eccentric phase. However, no differences in common drive were detected from before- to after-intervention measures in any of the conditions. The time period toward the end of the plateau phase of before-intervention trapezoid force trace efforts displayed the greatest absolute and relative reliability and was therefore used for motor unit firing rate and common drive analysis. The purpose of the fifth chapter was to compare acute neuromuscular and kinetic responses between multiple-joint AEL and CL back squats. Strength-trained males completed two experimental test day sessions where back squat repetitions (AEL or CL) were performed. Neuromuscular and kinetic responses were measured during each condition. No differences in concentric neuromuscular or concentric kinetic variables during back squat repetitions were detected between conditions. Elevated eccentric phase neuromuscular activation was observed during the AEL compared to the CL condition in two to three of the four sets performed for the following lower-body muscles: (i) vastus lateralis (p< 0.001, f= 15.58); (ii) vastus medialis (p< 0.001, f= 10.77); (iii) biceps femoris (p= 0.003, f= 6.10); and (iv) gluteus maximus (p= 0.001, f= 7.98). There were no clear differences in terms of the neuromuscular activation contributions between muscles within AEL or CL conditions during eccentric or concentric muscle actions. Following the investigation of acute motor unit firing rate and common drive responses to lower limb single-joint AEL and CL in the fourth chapter of the thesis, the question arose as to whether or not similar responses would occur in a more complex model, such as a multiple-joint resistance exercise. Multiple-joint resistance exercise poses different neuromuscular activation, coordination, and stabilisation demands. Therefore, the purpose of the sixth chapter of the thesis was to compare acute motor unit firing rate and common drive responses following multiple-joint lower-body free weight AEL and CL.