An examination of athletes' self-efficacy and strength training effort during an entire off-season

Over the past 30-plus years in which self-efficacy (or confidence at a task) has been researched, findings have shown that in almost every domain of human functioning, self-efficacy positively relates to effort, persistence, and other adaptive behaviors. However, in the past decade, new research postulating that too much self-efficacy can lead to complacency and a subsequent downturn in behavior or performance has also experienced resurgence in the literature. Therefore, the purpose of this study was to test these opposing viewpoints regarding self-efficacy and effort for Division I athletes in a strength and conditioning domain over off-season training, a procedure yet to be undertaken. Subjects (N = 99), from 4 different sports (M(ag)e = 20.0 years, SD = 1.2 years), completed self-efficacy and effort measures at 4 distinct time points during off-season training. In addition, strength and conditioning coaches also rated each subject's effort--at each time point--so that a more valid measure of this construct could be attained. Results were analyzed using a multilevel approach and revealed that self-efficacy was positively, and significantly, related to the current effort that athletes exerted in strength training sessions. Consequently, practitioners are advised to structure strength and conditioning training sessions and the overall environment in ways that will positively impact the 4 proven sources of self-efficacy.     

An examination of current practices and gender differences in strength and conditioning in a sample of varsity high school athletic programs

Currently, little is known about strength and conditioning programs at the high school level. Therefore, the purpose of this research was to explore current practices in strength and conditioning for varsity high school athletes in selected sports. The following were specifically examined: who administers programs for these athletes, what kinds of training activities are done, and whether the responsible party or emphasis changes depending on the gender of the athletes. Coaches of varsity soccer, basketball, softball, and baseball in 3 large Idaho school districts were asked to complete an online survey. Sixty-seven percent (32/48) of the questionnaires were completed and used for the study. The majority of coaches (84%) provided strength and conditioning opportunities for their athletes, although only 37% required participation. Strength training programs were designed and implemented primarily by either physical education teachers or head coaches. Compared with coaches of male athletes, coaches of female athletes were less likely to know the credentials of their strength coaches, and they were less likely to use certified coaches to plan and implement their strength and conditioning programs. Most programs included dynamic warm-ups and cool-downs, plyometrics, agility training, speed training, and conditioning, and most programs were conducted 3 d·wk(-1) (76%) for sessions lasting between 30 and 59 minutes (63%). Compared with their female counterparts, male athletes were more likely to have required training, participate in strength training year round, and train using more sessions per week. This study provides additional information related to the practice of strength and conditioning in a sample of high school athletic teams.     

Practices of strength and conditioning coaches in Brazilian elite soccer

Brazil is the leading global exporter of soccer players, with approximately 2,000 international transfers to different clubs per year. Although Brazilian players compete in the most prestigious soccer leagues worldwide, the habitual training methods, strategies, and routines of Brazilian soccer strength and conditioning coaches (SCCs) are undocumented. This study used a standard online survey to collect and characterize the strength and conditioning practices of Brazilian soccer SCCs. Forty-nine SCCs (age: 40.4 ± 7.5 years; professional experience: 15.3 ± 7.5 years) working in Brazilian professional soccer teams participated in this study. The survey consisted of eight sections: 1) background information; 2) muscular strength-power development; 3) speed training; 4) plyometrics; 5) flexibility training; 6) physical testing; 7) technology use; and 8) programing. Results indicated that training and testing practices of Brazilian SCCs are strongly affected by the congested fixture schedules, extensive traveling distances, and socio-economic disparities between different regions of the country. We describe all these different strategies and methods in detail, providing a comprehensive view and a critical examination of Brazilian soccer strength and conditioning practices. Brazilian SCCs and professional soccer organizations can use the findings from this study to develop training strategies and customize education programs. Practitioners from other countries can use this information to design training programs closely tailored to the background of Brazilian athletes, which may support their adaptation to different competitive scenarios and game demands, such as those found in the most important soccer leagues worldwide.     

Strength and conditioning practices of Major League Baseball strength and conditioning coaches

This study describes the results of a survey of the practices of Major League Baseball strength and conditioning (MLB S&C) coaches. The response rate was 70.0% (21 of 30). This survey examines (a) background information, (b) physical testing, (c) flexibility development, (d) speed development, (e) plyometrics, (f) strength/power development, (g) unique aspects, and (h) comments. Results indicate, in part, that coaches assess an average of 3.6 parameters of fitness, with body composition testing being the most commonly assessed parameter. All coaches use a variety of flexibility development strategies. All coaches use speed development strategies, with form running drills being the most common. Twenty of 21 (95.2%) coaches employ plyometric exercises with their athletes. Eighteen of 21 (85.7%) of MLB S&C coaches follow a periodization model (PM). Five of 21 coaches (23.8%) indicated that their athletes use Olympic-style lifts. The squat and its variations and the lunge and its variations were most frequently identified as the first and second most important exercises used to train the athletes. This survey provides detailed information about strength and conditioning practices at the most competitive level of baseball and serves as a review, as well as a source of applied information and new ideas.     

Job analysis of college Division I-A football strength and conditioning coaches

This investigation consisted of a job analysis of 6 National Collegiate Athletic Association Division I-A strength and conditioning coaches (SCC). All the subjects in the study were primarily responsible for providing strength and conditioning services to their institution's football programs. The procedures used for the gathering of data consisted of 3 questionnaires and a semi-structured interview. The questionnaires were followed up by the semi-structured interview. The purpose of this format was to use the semi-structured interview to delve more deeply into the issues raised by the questionnaires. The major job responsibilities and tasks are highlighted. These included conducting training session for athletes, disciplining athletes for infractions of team rules, on campus recruiting, and professional scout liaison to the National Football League. These coaches' perceptions concerning their profession, work environment, relationships with supervisors and co-workers, and the effect the job has on their spouses and other family members are also emphasized.     

Strength and conditioning practices of National Hockey League strength and conditioning coaches

This study describes the results of a survey of the practices of National Hockey League strength and conditioning (NHL S&C) coaches. The response rate was 76.6% (23 of 30). This survey examines (a) background information, (b) physical testing, (c) flexibility development, (d) speed development, (e) plyometrics, (f) strength/power development, (g) unique aspects, and (h) comments. Results indicate, in part, that coaches assess an average of 7.2 parameters of fitness, with tests of strength and power being the most common. All coaches used a variety of flexibility-development strategies. Results reveal that 21 of 23 (91.3%) of NHL S&C coaches follow a periodization model (PM). Of the coaches who follow a PM, 21 of 21 (100%) indicated that their athletes used Olympic-style lifts, and 21 of 21 coaches (100%) trained athletes with plyometric exercises. For those who used plyometrics with their athletes, 17 of 21 (80.1%) reported no plyometric-related injuries in the past year. Coaches who report they did not follow a PM also did not use Olympic-style lifts, plyometrics, or speed development strategies, such as assisted, resisted, or interval training, with their athletes. Finally, coaches reported that the squat and their variations, as well at the Olympic-style lifts and its variations, were most frequently used with their athletes. The survey serves as a review, as well as a source of applied information and new ideas.     

Strength and conditioning practices in rowing

There is limited published research on the practices of strength and conditioning (S &C) coaches in Great Britain. Information about training program design would be useful in developing models of good practice and ecologically valid intervention studies. The aim of this research was to quantify the training practices of coaches responsible for the S&C of rowing athletes. A questionnaire was developed that consisted of 6 sections: (a) personal details, (b) physical testing, (c) strength and power development, (d) flexibility development, (e) unique aspects of the program, and (f) any further relevant comments regarding the athletes prescribed training program. Twenty-two rowing and 10 S&C coaches with an average of 10.5 ± 7.2 years' experience agreed to complete the questionnaire. Approximately, 34% coached rowers of Olympic standard, 34% coached national standard, 3% coached regional standard, 19% coached club standard, and 10% coached university standard rowers. All coaches agreed that strength training enhanced rowing performance and the majority (74%) indicated that athletes' strength trained 2-3 times a week. Almost all coaches (94%) reported their rowers performed strength training, with 81% using Olympic lifting, and 91% employing a periodized training model. The clean (63%) and squat (27%) were rated the most important prescribed exercises. Approximately 50% of coaches used plyometrics such as depth jumps, box drills, and standing jumps. Ninety-four percent indicated they conducted physical testing on their rowers, typically assessing cardiovascular endurance (80%), muscular power (70%), muscular strength (70%), and anaerobic capacity (57%). This research represents the only published survey to date on the S&C practices in rowing within Great Britain.     

A survey of the scientific data and training methods utilized by collegiate strength and conditioning coaches

The purpose of this study was to determine the extent to which scientific research influences college strength and conditioning coaching practices and to determine the training methods utilized. A total of 321 surveys were mailed to Division I strength and conditioning coaches, and the response rate was 42.7% (137 of 321 surveys). Results indicate that all subjects held a baccalaureate degree, the majority in a human performance-related field, and that 75% were Certified Strength and Conditioning Specialist (CSCS) certified. The respondents' most widely utilized professional resources were the Strength and Conditioning Journal (94%) and other collegiate coaches and programs (93%). Forty-seven percent of respondents indicated that other collegiate coaches and their programs were the most important sources of knowledge outside of formal education. The majority indicated that they used a periodization protocol (93%) utilizing multiple sets (97%), plyometrics (90%), explosive movements (88%), and Olympic lifts (85%). Respondents tend to rely on sources of information that may not be defined as scientific, as evidenced by the low priority given to peer-reviewed literature. Respondents also tend to employ the methods they utilized as athletes. Reliance on these sources may not take advantage of advances made through scientific research in exercise physiology, biomechanics, and more specifically the area of strength and conditioning.     

Strength and conditioning practices of National Basketball Association strength and conditioning coaches

This study describes the results of a survey of the practices of National Basketball Association strength and conditioning (NBA S&C) coaches. The response rate was 68.9% (20 of 29). This survey examines (a) background information, (b) physical testing, (c) flexibility development, (d) speed development, (e) plyometrics, (f) strength/power development, (g) unique aspects, and (h) comments from coaches providing additional information. Results indicate, in part, that coaches assess an average of 7.3 parameters of fitness, with body composition testing being the most common. All coaches used a variety of flexibility development strategies. Results reveal that 17 of 20 (85.0%) of NBA S&C coaches follow a periodization model. Nineteen of 20 coaches (95.0%) indicated that their athletes used Olympic-style lifts. All coaches employed plyometric exercises with their athletes. The squat and its variations, as well as the Olympic-style lifts and their variations, were the most frequently used exercises. The survey serves as a review and a source of applied information and new ideas.     

A physical profile of elite female ice hockey players from the USA

Despite impressive numbers of hockey participants, there is little research examining elite female ice hockey players. Therefore, the purpose of this study was to describe the physical characteristics of elite female ice hockey players who were trying out for the 2010 US Women's Ice Hockey team. Twenty-three women participated in the study and were evaluated for body mass (kilograms), height (centimeters), age (years) vertical jump (centimeters), standing long jump (centimeters), 1RM front squat (kilograms), front squat relative to body mass (percent), 1RM bench press (kilograms), bench press relative to body mass (percent), pull-ups, and body composition (percent body fat). The athletes in this sample were 24.7 years of age (SD = 3.1) and 169.7 cm tall (SD = 6.9); on average, they weighed 70.4 kg (SD = 7.1) and reported 15.8% body fat (SD = 1.9). Mean vertical jump height was 50.3 cm (SD = 5.7) and standing long jump was 214.8 cm (SD = 10.9). Mean 1RM for the upper body strength (bench press) was 65.3 kg (SD = 12.2) (95.1 ± 15.5% of body mass), and 1RM for lower body (front squat) was 88.6 kg (SD = 11.2) (127.7 ± 16.3% of body mass). This study is the first to report the physical characteristics of elite female ice hockey players from the USA. Data should assist strength and conditioning coaches in identifying talent, testing for strengths and weaknesses, comparing future teams to these indicators, and designing programs that will enhance the performance capabilities of female ice hockey athletes.     

Using goal orientations to understand motivation in strength training

Despite the importance that today's athletics place on strength training, research exploring the motivation of athletes in this arena is sparse. It is known that not all athletes will use the same motivational cognitions as inspiration, and these differences can be explored through achievement goal orientations. Through questionnaire data and semistructured interviews, the present study investigated how collegiate athletes maintain high levels of motivation over a period of time during strength training and explored relationships among five goal orientations: task-orientation, self-enhancing ego-orientation, self-defeating ego-orientation, social-approval orientation, and work-avoidance orientation. Subjects (N = 133), comprising 90 men and 43 women, were current varsity collegiate athletes from 15 different sports at a major Midwestern university. In addition, using a screener survey to assess achievement goal orientations, 15 subjects from the sample group who demonstrated a stronger inclination to only one achievement goal orientation were interviewed to gain a more in-depth understanding of their motivation cognitions in strength training. Results showed that the strongest achievement goal orientations reported from all athletes were task-orientation and social-approval. Additionally, five higher-order themes (significant others, improvement, competitive demands, being stronger than others, and miscellaneous) were consistent among the interviewed athletes when describing how they stay motivated during strength training. Whereas all athletes were able to describe at least one motivational strategy they employed during strength training, the dominant achievement goal orientation of some athletes influenced their motivational strategy. By employing the T.A.R.G.E.T. model (), strength coaches can foster adaptive achievement goal orientations and thereby enhance intrinsic motivation for athletes engaging in strength training.     

Validation of an electronic jump mat to assess stretch-shortening cycle function

The purpose of this investigation was to determine the concurrent validity of a commonly used electronic switch mat (ESM), or jump mat, compared with force plate (FP) data. The efficiency of collection and accuracy of data are paramount to athlete and player field testing for the strength and conditioning coach who often has access only to a jump mat. Ten subjects from 5 different sporting backgrounds completed 3 squat jumps (SJs), 3 countermovement jumps (CMJs), and 3 drop jumps (DJs). The jumps were performed on an AMTI FP operating at 1,000 Hz with an ESM positioned on top of the platform. All the subjects were experienced with the protocols involved with jump testing. The resulting absolute errors between FP and ESM data were 0.01, 0.02, and 0.01 m for CMJ, SJ, and DJ heights, respectively. However, the coefficient of variation for the DJ contact time (CT) was 57.25%, CMJ (r = 0.996), and SJ (r = 0.958) heights correlated very strongly with force platform data, and DJ data were not as strong (r = 0.683). Confidence interval tests revealed bias toward CMJ and SJ (p < 0.05). The jump mat can accurately calculate the CMJ height, SJ height, and reactive strength index for all the 3 jump protocols. However, the faster CTs and rapid movements involved in a DJ may limit its reliability when giving measures of CT, flight time, and height jumped for DJs. Strength and conditioning coaches can use such a jump mat device with the confidence that it is accurately producing valid measurements of their athlete's performance for CMJ and SJ slow SSC protocols.     

Changes in strength over a 2-year period in professional rugby union players

The purpose of this study was to assess the magnitude of upper and lower body strength changes in highly trained professional rugby union players after 2 years of training. An additional purpose was to examine if the changes in strength were influenced by the starting strength level, lean mass index (LMI), or chronological age. This longitudinal investigation tracked maximal strength and body composition over 3 consecutive years in 20 professional rugby union athletes. Maximal strength in the bench press and back squat and body composition was assessed during preseason resistance training sessions each year. The athletes completed a very rigorous training program throughout the duration of this study consisting of numerous resistance, conditioning and skills training sessions every week. The primary findings of this study were as follows: (a) Maximal upper and lower body strength was increased by 6.5-11.5% after 2 years of training (p = 0.000-0.002 for bench press; p = 0.277-0.165 for squat); (b) magnitude of the improvement was negatively associated with initial strength level (r = -0.569 to -0.712, p ≤ 0.05); (c) magnitude of improvement in lower body maximal strength was positively related to the change in LMI (an indicator of hypertrophy; r = 0.692-0.880, p ≤ 0.05); and (d) magnitude of improvement was not associated with the age of professional rugby union athletes (r = -0.068 to -0.345). It appears particularly important for training programs to be designed for continued muscle hypertrophy in highly trained athletes. Even in professional rugby union athletes, this must be achieved in the face of high volumes of aerobic and skills training if strength is to be increased.     

Influence of strength training background on postactivation potentiation response

The aim of this study was to evaluate the influence of the subjects' level of maximal dynamic strength and training background on postactivation potentiation (PAP). A group of 23 subjects, composed of power track-and-field athletes (PT = 8), bodybuilders (BB = 7), and physically active subjects (PA = 8), participated in the study. Maximal dynamic strength (1 repetition maximum test) was assessed in the leg press exercise for subjects' characterization. Their countermovement vertical jump (CMJ) performance was assessed before and after 2 different conditioning activity (CA) protocols (1 or 3 maximum voluntary isometric contractions [MVICs] of 5-second duration in the leg press exercise) or after control (no CA), performed on separate days. No significant differences among groups were found for CMJ height or take-off velocity after any of the CA protocols (p ≤ 0.05). However, individual analysis showed that some subjects increased performance in response to the CA, despite their previous training history. We concluded that subjects' level of maximal dynamic strength and training background have no influence on PAP manifestation. Our data suggest that coaches should individually identify the athletes that are PAP responders before introducing MVICs as part of their warm-up routines.     

Contemporary practices of strength and conditioning coaches in professional soccer

This study describes the contemporary practices of strength and conditioning coaches in professional soccer. Fifty-two strength and conditioning coaches from professional leagues across 18 countries completed an online survey, consisting of 45 questions, with eight sections: (a) background information, (b) muscular strength and power development, (c) speed development, (d) plyometrics, (e) flexibility development, (f) physical testing, (g) technology use, and (h) programing. A frequency analysis was used to assess and report responses to fixed response questions, and thematic-analysis used for open-ended questions to create clear, identifiable and distinct themes. All strength and conditioning coaches were educated to degree level or higher, 65% held strength and conditioning certifications and 54% held soccer coaching certifications. Concentric (100%) and eccentric (98%) modes of resistance were the most commonly prescribed, whereas the squat (including variations) (52%) was deemed the most important exercise for soccer players. Hang clean (33%) and multiple hops/lunges (89%) were the most programed Olympic weightlifting and plyometric exercises. Global Positioning Systems (94%) were the most utilized technology-based equipment. Time, scheduling and fixtures were the biggest issues faced, which made it difficult to periodize training programs and apply appropriate training loads. Furthermore, strength and conditioning coaches would like to further integrate technology to comprehensively monitor and test players, while also believing that technology will continue to be developed and integrated in the future. Strength and conditioning coaches from professional soccer can use the information from this study to review current practices and also provide ideas for diversifying or modifying future practices.     

Correlates of tackling ability in high-performance rugby league players

This study investigated the tackling ability of high-performance rugby league players and determined the relationship between physiological and anthropometric qualities and tackling ability in these athletes. Twenty professional (National Rugby League) and 17 semiprofessional (Queensland Cup) rugby league players underwent a standardized 1-on-1 tackling drill in a 10-m grid. Video footage was taken from the rear, side, and front of the defending player. Tackling proficiency was assessed using standardized technical criteria. In addition, all players underwent measurements of standard anthropometry (height, body mass, and sum of 7 skinfolds), acceleration (10-m sprint), change of direction speed (505 test), and lower body muscular power (vertical jump). Professional players had significantly greater (p ≤ 0.05) tackling proficiency than semiprofessional players (87.5 ± 2.0 vs. 75.0 ± 2.3%). Professional players were significantly (p ≤ 0.05) older, more experienced, leaner, and had greater acceleration than semiprofessional players. The strongest individual correlates of tackling ability were age (r = 0.41, p ≤ 0.05), playing experience (r = 0.70, p ≤ 0.01), skinfold thickness (r = -0.59, p ≤ 0.01), acceleration (r = 0.41, p ≤ 0.05), and lower body muscular power (r = 0.38, p ≤ 0.05). When hierarchical multiple regression analysis was performed to determine which of the variables predicted tackling ability, playing experience and lower body muscular power were the only variables that contributed significantly (r2 = 0.60, p ≤ 0.01) to the predictive model. From a practical perspective, strength and conditioning coaches should emphasize the development of acceleration, lower body muscular power, and lean muscle mass to improve tackling ability in high-performance rugby league players.     

Physical demands, injuries, and conditioning practices of stock car drivers

The purpose of this study was to assess the physical demands, injuries, and conditioning practices of stock car drivers. Forty stock car drivers from 27 states in the United States participated in the interviews for 43.9 ± 13.9 minutes. The interviews examined background information, the physical demands of racing, injuries associated with racing, and the athletic and fitness background and practices of the subjects. Numerical data were analyzed using Pearson's correlation coefficients. Responses to open-ended questions were analyzed using inductive content analysis. Results revealed significant correlation between track points standings and the length of the resistance training sessions (R = -0.71, p = 0.002) and subject self-assessment of their fitness (R = -0.53, p = 0.045). Results also revealed that "upper-body strength" was identified as the most important physical demand. Extreme fatigue was the most common feeling after a demanding race. Subjects reported that shoulder fatigue was the most common form of muscle soreness experienced after a race. Back and torso injuries were the most common injury, although head injuries most frequently required medical attention. The subjects' biggest fear was fire, followed closely by head and neck injury. The bench press and running were the most commonly performed resistance training and cardiovascular exercises, respectively. Subjects reported that their highest motivation for training was to improve their racing performance. Many subjects had athletic backgrounds with football identified as the sport they had most commonly participated in. This study provides additional detailed information. Results of this study can assist strength and conditioning professionals in the development of strength and conditioning programs for performance enhancement and injury prevention that are specific to the needs of this population of athletes.     

Adaptations in upper-body maximal strength and power output resulting from long-term resistance training in experienced strength-power athletes

The purpose of this investigation was to observe changes in maximal upper-body strength and power and shifts in the load-power curve across a multiyear period in experienced resistance trainers. Twelve professional rugby league players who regularly performed combined maximal strength and power training were observed across a 4-year period with test data reported every 2 years (years 1998, 2000, and 2002). Upper-body strength was assessed by the 1 repetition maximum bench press and maximum power during bench press throws (BT Pmax) with various barbell resistances of 40-80 kg. During the initial testing, players also were identified as elite (n = 6) or subelite (n = 6), depending upon whether they participated in the elite first-division national league or second-division league. This subgrouping allowed for a comparison of the scope of changes dependent upon initial strength and training experience. The subelite group was significantly younger, less strong, and less powerful than the elite group, but no other difference existed in height or body mass in 1998. Across the 4-year period, significant increases in strength occurred for the group as a whole and larger increases were observed for the subelite than the elite group, verifying the limited scope that exists for strength gain in more experienced, elite resistance-trained athletes. A similar trend occurred for changes in BT Pmax. This long-term observation confirms that the rate of progress in strength and power development diminishes with increased strength levels and resistance training experience. Furthermore, it also indicates that strength and power can still be increased despite a high volume of concurrent resistance and endurance training.     

The effect of acute stretching on agility performance

Static stretching (SS) has shown decreases in many areas including strength, anaerobic power, and sprinting time. Dynamic stretching (DS) has shown increases in anaerobic power and decreases in sprinting time. Research on the effects of stretching on agility performance is limited. The purpose of this study was to determine the effect of SS and DS on performance time of a sport agility test. Sixty male subjects consisting of collegiate (n = 18) and recreational (n = 42) basketball athletes volunteered for the study. Subjects were randomly assigned to 1 of 3 intervention groups: SS, DS, or no stretching (NS). All groups completed a 10-minute warm-up jog followed by a 3-minute rest. The SS and DS groups then completed an 8.5-minute stretching intervention. Next, all subjects completed 3 trials of the 505 agility test with 2-5 minutes of rest between trials. A 2-way repeated-measure analysis of variance (Stretch group, athlete category, group × athlete interaction) was used to determine statistical significance (p < 0.05). A Tukey post hoc test was performed to determine differences between groups. For all athletes, the DS group produced significantly faster times on the agility test (2.22 ± 0.12 seconds, mean ± SD) in comparison to both the SS group (2.33 ± 0.15 seconds, p = 0.013) and NS group (2.32 ± 0.12 seconds, p = 0.026). Differences between the SS and NS groups revealed no significance (p = 0.962). There was a significant difference in mean times for the type of athlete (p = 0.002); however, interaction between the type of athlete and stretching group was not significant (p = 0.520). These results indicate that in comparison to SS or NS, DS significantly improves performance on closed agility skills involving a 180° change of direction.     

Effect of mechanomyography as a biofeedback method to enhance muscle relaxation and performance

The purpose of the study was to examine the potential for using the mechanomyographic (MMG) signal as a biofeedback method to enhance muscular relaxation and to improve performance during forearm flexion repetitions to fatigue. Twelve adult (mean +/- SD; age: 22.0 +/- 1.1 years) moderately trained subjects (weight: 82.3 +/- 29.2 kg; height: 165.7 +/- 49.0 cm) were instructed to relax the biceps brachii muscle using MMG biofeedback (BIO) provided by viewing a computer screen graphically displaying the MMG signal and then without using MMG biofeedback (NOBIO). Electromyographic (EMG) and MMG signals were detected midway over the biceps brachii during the relaxation protocol. In subsequent visits to the laboratory, subjects performed as many repetitions as possible at 85% of 1 repetition maximum with BIO and NOBIO using the seated preacher curl exercise. Two-way (biofeedback x gender) mixed factorial analyses of variance revealed significantly (p < 0.05) lower MMG (mean +/- SEM; BIO = 0.6 +/- 0.1 mV; NOBIO = 1.1 +/- 0.2 mV) and EMG amplitudes (BIO = 6.6 +/- 0.6 microV; NOBIO = 9.4 +/- 1.4 microV) for BIO when subjects were instructed to relax the biceps brachii muscle. There was no significant difference in the number of forearm flexion repetitions performed for BIO (mean +/- SD; 7.9 +/- 0.4 reps) vs. NOBIO (8.1 +/- 0.6 reps). The results of the present study revealed that using MMG as a biofeedback technique can enhance the development of muscle relaxation, but is not useful in delaying fatigue during forearm flexion repetitions. Our results may have been influenced by a relatively short training phase designed to teach subjects to use the MMG signal as a biofeedback method. Future studies are needed to determine whether MMG biofeedback can be used for other purposes. If MMG is found to be useful as a biofeedback method, it has some distinct practical advantages over EMG that the strength and conditioning athlete and professional may find appealing.