An examination of training on the VertiMax resisted jumping device for improvements in lower body power in highly trained college athletes

Training to develop superior muscular power has become a key component to most progressive sport conditioning programs. Conventional resistance training, plyometrics, and speed/agility modalities have all been employed in an effort to realize superlative combinations of training stimuli. New training devices such as the VertiMax resisted jump trainer are marketed as a means of improving lower body reactive power. The purpose of this study was to evaluate the effectiveness of the VertiMax, in combination with traditional training modalities, for improvements in lower body power among highly trained athletes. Forty men and women Division I collegiate athletes representing the sports of baseball, basketball, soccer, gymnastics, and track completed a 12-week mixed-methods training program. Two groups were constructed with both groups performing the same conventional resistance training and strength training exercises. The training control group performed traditional plyometric exercises while the experimental group performed similar loaded jump training on the VertiMax. Lower body power was measured before and after the training program by the TENDO FiTROdyne Powerlizer and statistically compared for differences between groups. Data analyses identified a significant (p < 0.05) and meaningful difference between power development among the 2 groups, with the VertiMax eliciting a greater treatment effect (effect size = 0.54) over conventional resistance and plyometric training alone (effect size = 0.09). These data convincingly demonstrate that the VertiMax represents an effective strategy for developing lower body power among trained college athletes, when combined with traditional strength and conditioning approaches.     

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.     

Electromyostimulation--a systematic review of the influence of training regimens and stimulation parameters on effectiveness in electromyostimulation training of selected strength parameters

Our first review from our 2-part series investigated the effects of percutaneous electromyostimulation (EMS) on maximal strength, speed strength, jumping and sprinting ability, and power, revealing the effectiveness of different EMS methods for the enhancement of strength parameters. On the basis of these results, this second study systematically reviews training regimens and stimulation parameters to determine their influence on the effectiveness of strength training with EMS. Out of about 200 studies, 89 trials were selected according to predefined criteria: subject age (<35 years), subject health (unimpaired), EMS type (percutaneus stimulation), and study duration (>7 days). To evaluate these trials, we first defined appropriate categories according to the type of EMS (local or whole-body) and type of muscle contraction (isometric, dynamic, isokinetic). Unlike former reviews, this study differentiates between 3 categories of subjects based on their level of fitness (untrained subjects, trained subjects, and elite athletes) and on the types of EMS methods used (local, whole-body, combination). Special focus was on trained and elite athletes. Untrained subjects were investigated for comparison purposes. The primary purpose of this study was to point out the preconditions for producing a stimulus above the training threshold with EMS that activates strength adaptations to give guidelines for implementing EMS effectively in strength training especially in high-performance sports. As a result, the analysis reveals a significant relationship (p < 0.05) between a stimulation intensity of ≥50% maximum voluntary contraction (MVC; 63.2 ± 19.8%) and significant strength gains. To generate this level of MVC, it was possible to identify guidelines for effectively combining training regimens (4.4 ± 1.5 weeks, 3.2 ± 0.9 sessions per week, 17.7 ± 10.9 minutes per session, 6.0 ± 2.4 seconds per contraction with 20.3 ± 9.0% duty cycle) with relevant stimulation parameters (impulse width 306.9 ± 105.1 microseconds, impulse frequency 76.4 ± 20.9 Hz, impulse intensity 63.7 ± 15.9 mA) to optimize training for systematically developing strength abilities (maximal strength, speed strength, jumping and sprinting ability, power).     

Effects of a 4-month season on glenohumeral joint rotational strength and range of motion in female collegiate tennis players

The purpose of this study was to examine the effects of a 4-month season of collegiate tennis on glenohumeral joint internal and external rotation strength and range of motion in female collegiate tennis players. Eleven female collegiate tennis players were isokinetically tested to assess glenohumeral joint internal and external rotation strength with 90 degrees of abduction on a Cybex 6000 isokinetic dynamometer. Subjects were also measured for internal and external rotation range of motion using a universal goniometer with 90 degrees of abduction. Measurements were taken before and immediately after a 4-month season of competitive collegiate tennis play. A repeated-measures analysis of variance showed no significant difference in internal or external rotation strength or range of motion between pre- and postseason measures. Results from this study show that, despite 4 months of competitive tennis play, changes in rotational strength and range of motion did not occur. These data have implications for clinicians as well as strength and conditioning professionals designing rehabilitation and preventative conditioning programs for athletes in this population.     

Professional development themes in strength and conditioning coaches

The purpose of this study was to explore professional development themes in experienced strength and conditioning coaches. Strength and conditioning coaches (N = 15, mean age = 34.3 years, SD = 5.2 years) with 11.4 (SD = 4.9) years experience working with elite, professional, or talented athletes were interviewed about their professional development. The interviews were transcribed verbatim and content analyzed. Over time, subjects' service-delivery practices became more flexible and client driven. Their role understanding also broadened to include various dimensions, such as the need to consider various stakeholders and the value of good relationships with athletes. The subjects shifted from relying on external justification for professional decision making to their experience-based knowledge. The subjects believed athlete work experience, interactions with senior strength and conditioning coaches and other colleagues, the professional literature, and nonprofessional experiences, such as their own athletic experience and sales or managerial training, were the primary influences on their professional development. Typically, the subjects experienced anxiety about their competence, both early in their careers and when working in new contexts or with new athlete groups, but over time, they developed increased confidence. In addition, the subjects experienced reduced narcissism over time about the control they had over athletes and their competitive results. The current results provide information about the characteristics of effective strength and conditioning coaches, the ways they develop their competencies to help athletes, and the emotions they experience throughout their careers. These results may help strength and conditioning practitioners in planning and optimizing their professional development and effectiveness with 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.     

Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes

Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.     

The effects of EMG biofeedback on strength acquisition

This study investigated the effectiveness of electromyographic (EMG) biofeedback in maximizing strength gains and integrated electromyographic (IEMG) levels of the quadriceps muscle group resulting from an isokinetic exercise program. Twenty-one male volunteers recruited from physical education classes at a large southwestern university were randomly assigned to one of the following three treatment groups: (1) a biofeedback (BF) trained group, (2) a deception (DEC) trained group, and (3) a nonfeedback (NF) trained group. Subjects were trained and tested for strength by extension on a Cybex Isokinetic Exercise Machine at a speed of 30 degrees per second. Training sessions were performed three times per week for five weeks; pretest and posttest data were based on the best score of three trials of a 1-RM maximum effort. A pretraining to posttraining comparison indicated significant increases in strength (p less than .001) and IEMG levels (p less than .001) for all treatment groups when a paired t test was applied to the data. A multivariate analysis of covariance (MANCOVA) revealed that the BF trained group showed significantly greater peak torque values than DEC and NF trained groups (p less than .01) and produced significantly greater IEMG levels than the NF trained group (p less than .05). Overall, these results were taken as supporting the hypothesis that a training program of combined isokinetics and EMG biofeedback produces significant gains in maximal force and IEMG activity of leg-extensor muscles.     

The effect of different rest intervals between sets on volume components and strength gains

The purpose of this study was to compare squat strength gains and volume components when resting 2 minutes vs. 4 minutes between sets over multiple mesocycles. After the first squat 1 repetition maximum, 15 trained men were matched and randomly assigned to either a 2-minute (n = 7) or a 4-minute (n = 8) rest interval group. Each group performed the same training program, with the only difference being the length of the rest interval between sets. Subjects performed two squat workouts per week; one was labeled as Heavy and the other was labeled as Light. The squat workouts varied in the intensity, number of sets, and repetitions performed per set in a nonlinear periodized manner throughout each mesocycle. Differences in strength gains and volume components (the load utilized per set, the repetitions performed per set, the intensity per set, and the volume performed per workout) were compared between groups. Both groups demonstrated large strength gains; however, these differences were not significant between groups (P = 0.47). During all mesocycles, the 4-minute group demonstrated significantly higher total volumes for the Heavy workouts (P < 0.05). The findings of the present study indicate that large squat strength gains can be achieved with a minimum of 2 minutes' rest between sets, and little additional gains are derived from resting 4 minutes between sets. Therefore, athletes attempting to achieve specific volume goals may need longer rest intervals initially but may later adapt so that shorter rest intervals can be utilized without excessive fatigue, leaving additional time to focus on other conditioning priorities.     

Electromyostimulation--a systematic review of the effects of different electromyostimulation methods on selected strength parameters in trained and elite athletes

This is the first part of 2 studies that systematically review the current state of research and structure the results of selected electromyostimulation (EMS) studies in a way that makes accurate comparisons possible. This part will focus on the effects of EMS on strength enhancement. On the basis of these results, part 2 will deal with the influence of the training regimen and stimulation parameters on EMS training effectiveness to make recommendations for training control. Out of about 200 studies, 89 trials were selected according to predefined criteria: subject age (<35 years), subject health (unimpaired), EMS type (percutaneous stimulation), and study duration (>7 days). To evaluate these trials, we first defined appropriate categories according to the type of EMS (local or whole body) and type of muscle contraction (isometric, dynamic, isokinetic). Then, we established the most relevant strength parameters for high-performance sports: maximal strength, speed strength, power, jumping and sprinting ability. Unlike former reviews, this study differentiates between 3 categories of subjects based on their level of fitness (untrained subjects, trained subjects, and elite athletes) and on the types of EMS methods used (local, whole-body, combination). Special focus was on trained and elite athletes. Untrained athletes were investigated for comparison purposes. This scientific analysis revealed that EMS is effective for developing physical performance. After a stimulation period of 3-6 weeks, significant gains (p < 0.05) were shown in maximal strength (isometric Fmax +58.8%; dynamic Fmax +79.5%), speed strength (eccentric isokinetic Mmax +37.1%; concentric isokinetic Mmax + 41.3%; rate of force development + 74%; force impulse + 29%; vmax + 19%), and power (+67%). Developing these parameters increases vertical jump height by up to +25% (squat jump +21.4%, countermovement jump +19.2%, drop jump +12%) and improves sprint times by as much as -4.8% in trained and elite athletes. With regard to the level of fitness, the analysis shows that trained and elite athletes, despite their already high level of fitness, are able to significantly enhance their level of strength to same extent as is possible with untrained subjects. The EMS offers a promising alternative to traditional strength training for enhancing the strength parameters and motor abilities described above. Because of the clear-cut advantages in time management, especially when whole-body EMS is used, we can expect this method to see the increasing use in high-performance sports.     

Moderate resistance training volume produces more favorable strength gains than high or low volumes during a short-term training cycle

The purpose of this study was to examine the effects of 3 resistance training volumes on maximal strength in the snatch (Sn), clean & jerk (C&J), and squat (Sq) exercises during a 10-week training period. Fifty-one experienced (>3 years), trained junior lifters were randomly assigned to one of 3 groups: a low-volume group (LVG, n = 16), a moderate-volume group (MVG, n = 17), and a high-volume group (HVG, n = 18). All subjects trained 4-5 days a week with a periodized routine using the same exercises and relative intensities but a different total number of sets and repetitions at each relative load: LVG (1,923 repetitions), MVG (2,481 repetitions), and HVG (3,030 repetitions). The training was periodized from moderate intensity (60- 80% of 1 repetition maximum [1RM]) and high number of repetitions per set (2-6) to high intensity (90-100% of 1RM) and low number of repetitions per set (1-3). During the training period, the MVG showed a significant increase for the Sn, C&J, and Sq exercises (6.1, 3.7, and 4.2%, respectively, p < 0.01), whereas in the LVG and HVG, the increase took place only with the C&J exercise (3.7 and 3%, respectively, p < 0.05) and the Sq exercise (4.6%, p < 0.05, and 4.8%, p < 0.01, respectively). The increase in the Sn exercise for the MVG was significantly higher than in the LVG (p = 0.015). Calculation of effect sizes showed higher strength gains in the MVG than in the HVG or LVG. There were no significant differences between the LVG and HVG training volume-induced strength gains. The present results indicate that junior experienced lifters can optimize performance by exercising with only 85% or less of the maximal volume that they can tolerate. These observations may have important practical relevance for the optimal design of strength training programs for resistance-trained athletes, since we have shown that performing at a moderate volume is more effective and efficient than performing at a higher volume.     

举重训练对男子肌比力、肌纤维的影响

安排9名有一定训练的青少年运动员参加10周举重训练。每周6次,每次8小时。训练前后用电子计算机—X线断层扫描技术(CT)测量大腿肌肉横断面积,股外肌针刺活检取样测定Ⅰ、Ⅱ型肌纤维％和面积。测定大腿伸膝肌最大随意等长力量。将结果(实验前、后)与对照组(13名无训练者)和优秀举重运动员(健将3人、一级4人)进行比较。结果表明,有训练人(实验前、后和优秀)与没有训练人(对照)在肌比力上存有差别。短、长期举重训练后,肌比力与Ⅱ型肌纤维％呈正相关。短、长期举重训练不曾改变肌纤维类型分布。举重训练对Ⅱ型肌纤维有选择性作用,且这个作用不受年龄的影响。结果还提示,肌比力的变化及肌比力与肌纤维之间的关系都会受运动项目专项特点的影响。     

An analysis of full range of motion vs. partial range of motion training in the development of strength in untrained men

The purpose of this investigation was to compare partial range of motion versus full range of motion training in the development of maximal strength. The bench press was used as the criterion measurement. The study was conducted over a 10-week period with training sessions occurring twice per week. Subjects were divided into 3 groups. Group 1 (N = 11) trained with 3 full range of motion sets on the bench press. Group 2 (N = 15) trained with 3 partial range of motion sets. A partial repetition was defined as one that is beyond the sticking point 2 to 5 inches from full extension of the elbows. Group 3 (N = 30) trained with a combination of partial and full range of motion sets. All subjects were pre- and posttested on the bench press through a full range of motion using a 1 repetition maximum. Each of the 3 groups demonstrated statistically significant increases in strength from pre- to posttest. No differences were found between groups. These findings appear to suggest that partial range of motion training can positively influence the development of maximal strength. Therefore, those involved in the strength and conditioning profession can confidently including this method as an adjunct to their normal training protocols when working with individuals similar to those found in this investigation. It is suggested that additional research be conducted to further establish the effectiveness of partial range of motion training in developing maximal strength.     

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.     

The effects of EMG biofeedback on strength acquisition

This study investigated the effectiveness of electromyographic (EMG) biofeedback in maximizing strength gains and integrated electromyographic (IEMG) levels of the quadriceps muscle group resulting from an isokinetic exercise program. Twenty-one male volunteers recruited from physical education classes at a large southwestern university were randomly assigned to one of the following three treatment groups: (1) a biofeedback (BF) trained group, (2) a deception (DEC) trained group, and (3) a nonfeedback (NF) trained group. Subjects were trained and tested for strength by extension on a Cybex Isokinetic Exercise Machine at a speed of 30 degrees per second. Training sessions were performed three times per week for five weeks; pretest and posttest data were based on the best score of three trials of a 1-RM maximum effort. A pretraining to posttraining comparison indicated significant increases in strength (p<.001)and IEMG levels (p<.001) for all treatment groups when a pairedt test was applied to the data. A multivariate analysis of covariance (MANCOVA) revealed that the BF trained group showed significantly greater peak torque values than DEC and NF trained groups (p<.01) and produced significantly greater IEMG levels than the NF trained group (p<.05). Overall, these results were taken as supporting the hypothesis that a training program of combined isokinetics and EMG biofeedback produces significant gains in maximal force and IEMG activity of leg-extensor muscles.This research was conducted while the author was at the University of New Mexico, Albuquerque, New Mexico.     

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.     

Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining.

Six women who had participated in a previous 20-wk strength training study for the lower limb detrained for 30-32 wk and subsequently retrained for 6 wk. Seven untrained women also participated in the 6-wk "retraining" phase. In addition, four women from each group volunteered to continue training an additional 7 wk. The initial 20-wk training program caused an increase in maximal dynamic strength, hypertrophy of all three major fiber types, and a decrease in the percentage of type IIb fibers. Detraining had relatively little effect on fiber cross-sectional area but resulted in an increased percentage of type IIb fibers with a concomitant decrease in IIa fibers. Maximal dynamic strength decreased but not to pretraining levels. Retraining for 6 wk resulted in significant increases in the cross-sectional areas of both fast fiber types (IIa and IIab + IIb) compared with detraining values and a decrease in the percentage of type IIb fibers. The 7-wk extension accentuated these trends such that cross-sectional areas continued to increase (nonsignificant) and no IIb fibers could be found. Similar results were found for the nonpreviously trained women. These data suggest that rapid muscular adaptations occur as a result of strength training in previously trained as well as non-previously trained women. Some adaptations (fiber area and maximal dynamic strength) may be retained for long periods during detraining and may contribute to a rapid return to "competitive" form.     

Force-generating capacities and fatigability of the quadriceps femoris in relation to different exercise modes

In this study, we examined whether different exercise modes provoke functional differences in maximal and explosive force-generating capacities and fatigability of the quadriceps femoris (QF). Additionally, the interaction of different functional capacities was studied in competitive athletes. Ten competitive tennis players and 10 endurance athletes participated in the study. Pre-exercise force-generating capacities were determined during maximal voluntary isometric knee extensions (MVC). Fatigability of the QF was studied using sustained isometric contractions with target loads of 20% and 40% of pre-exercise MVC. Postexercise MVCs were conducted 20 seconds, 1 minute, and 3 minutes post task failure. Muscle activation of the QF during the fatiguing exercises and postexercise MVCs was estimated using surface electromyography. Higher explosive force-generating capacities, but no differences in absolute moments, were detected in tennis players compared with endurance athletes. Fatigability of the QF during both fatiguing tasks was approximately the same in both athletic populations. This was indicated by minor group differences in endurance time, postexercise MVC production, and electromyography (EMG)-estimated muscle activation during fatigue. Variability in endurance time was not significantly associated with pre-exercise force-generating capacities in these competitive athletes. In both athletic populations, recovery of MVC was significantly slower after the fatiguing contraction with 20% of MVC compared with that with 40% of MVC. These results may enhance understanding of plasticity of the neuromuscular system and yield interesting information for the optimization of athletic training programs. Explosive strength training might enhance endurance athletes' explosiveness without decreasing muscle fatigue resistance. The exercise profile of competitive tennis is suggested to act as a sufficient trigger to reach high neuromuscular fatigue resistance but may be inadequate to cause significant gains in absolute muscle strength.