Eight weeks of ballistic exercise improves power independently of changes in strength and muscle fiber type expression

This study investigated the effects of ballistic resistance training and strength training on muscle fiber composition, peak force (PF), maximal strength, and peak power (PP). Fourteen males (age = 21.3 +/- 2.9, body mass = 77.8 +/- 10.1 kg) with 3 months of resistance training experience completed the study. Subjects were tested pre and post for their squat one-repetition maximum (1RM) and PP in the jump squat (JS). Peak force and rate of force development (RFD) were tested during an isometric midthigh pull. Muscle biopsies were obtained from the vastus lateralis for analysis of muscle fiber type expression. Subjects were matched for strength and then randomly selected into either training (T) or control (C) groups. Group T performed 8 weeks of JS training using a periodized program with loading between 26 and 48% of 1RM, 3 days per week. Group T showed significant improvement in PP from 4088.9 +/- 520.6 to 5737.6 +/- 651.8 W. Rate of force development improved significantly in group T from 12687.5 +/- 4644.0 to 25343.8 +/- 12614.4 N x s(-1). PV improved significantly from 1.59 +/- 0.41 to 2.11 +/- 0.75 m x s(-1). No changes occurred in PF, 1RM, or muscle fiber type expression for group T. No changes occurred in any variables in group C. The results of this study indicate that using ballistic resistance exercise is an effective method for increasing PP and RFD independently of changes in maximum strength (1RM, PF), and those increases are a result of factors other than changes in muscle fiber type expression.     

The effects of a 10-week,periodized, off-season resistance-training program and creatine supplementation among collegiate football players

The periodized resistance-training model has not been well documented in the literature. Further research is needed to determine if periodized resistance training in conjunction with creatine supplementation can cause changes in strength, performance, total body weight, girth, and lean muscle mass. Therefore, the purpose of this investigation was to determine the effects of periodized resistance training in conjunction with low-dose (LD) and high-dose (HD) creatine supplementation on strength, body composition, and anaerobic muscular endurance. Subjects were divided into 3 groups: LD, HD, and placebo (P). Testing took place pre-, mid-, and postsupplementation for the following: weight, body composition (fat-free mass and fat mass), 1 repetition maximum squat, and anaerobic muscular endurance testing. Results revealed no significant differences in either creatine group when compared with the P group. However, significant differences were noted over time. These data suggest that 10 weeks of periodized resistance training was effective for causing changes in strength, body composition, and anaerobic muscular endurance.     

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.     

Assessing kinematics and kinetics of functional electrical stimulation rowing

Hybrid functional electrical stimulation (FES) rowing has positive effects on cardiovascular fitness, producing significantly greater aerobic power than either upper body or FES exercise alone. However, there is minimal information on the kinematics, kinetics, and mechanical efficiency of FES-rowing in the spinal cord injured (SCI) population. This study examined the biomechanics of FES-rowing to determine how motions, forces, and aerobic demand change with increasing intensity. Six individuals with SCI and six able-bodied subjects performed a progressive aerobic capacity rowing test. Differences in kinematics (motion profiles), kinetics (forces produced by the feet and arms), external mechanical work, and mechanical efficiency (work produced/volume of oxygen consumed) were compared in able-bodied rowing vs. SCI FES-rowing at three comparable subpeak workloads. With increasing exercise intensity (measured as wattage), able-bodied rowing increased stroke rate by decreasing recovery time, while FES-rowing maintained a constant stroke rate, with no change in drive or recovery times. While able-bodied rowers increased leg and arm forces with increasing intensity, FES-rowers used only their arms to achieve a higher intensity with a constant and relatively low contribution of the legs. Oxygen consumption increased in both groups, but more so in able-bodied rowers, resulting in able-bodied rowers having twice the mechanical efficiency of FES-rowers. Our results suggest that despite its ability to allow for whole body exercise, the total force output achievable with FES-rowing results in only modest loading of the legs that affects overall rowing performance and that may limit forces applied to bone.     

Effects of linear vs. daily undulatory periodized resistance training on maximal and submaximal strength gains

The objective of this study was to verify the effect of 2 periodized resistance training (RT) methods on the evolution of 1-repetition maximum (1RM) and 8RM loads. Twenty resistance trained men were randomly assigned to 2 training groups: linear periodization (LP) group and daily undulating periodization (DUP) group. The subjects were tested at baseline and after 12 weeks for 1RM and 8RM loads in leg press (LEG) and bench press (BP) exercises. The training program was performed in alternated sessions for upper (session A: chest, shoulder and triceps) and lower body (session B: leg, back and biceps). The 12-week periodized training was applied only in the tested exercises, and in the other exercises, 3 sets of 6-8RM were performed. Both groups exhibited significant increases in 1RM loads on LEG and BP, but no statistically significant difference between groups was observed. The same occurred in 8RM loads on LEG and BP. However, DUP group presented superior effect size (ES) in 1RM and 8RM loads for LEG and BP exercises when compared to the LP group. In conclusion, periodized RT can be an efficient method for increasing the strength and muscular endurance in trained individuals. Although there was no statistically significant difference between periodization models, DUP promoted superior ES gains in muscular maximal and submaximal strength.     

Effect of twelve weeks of medicine ball training on high school baseball players

This study examined the effect of 12 weeks of medicine ball training on high school baseball players. Forty-nine baseball players (age 15.4 +/- 1.2 years) were randomly assigned using a stratified sampling technique to 1 of 2 groups. Group 1 (n = 24) and group 2 (n = 25) performed the same full-body resistance exercises according to a stepwise periodized model and took 100 bat swings a day, 3 days per week, with their normal game bat for 12 weeks. Group 2 performed additional rotational and full-body medicine ball exercises 3 days per week for 12 weeks. Pre- and post-testing consisted of a 3 repetition maximum (RM) dominant and nondominant torso rotational strength and sequential hip-torso-arm rotational strength (medicine ball hitter's throw). A 3RM parallel squat and bench press were measured at 0 and after 4, 8, and 12 weeks of training. Although both groups made statistically significant increases (p < or = 0.05) in dominant (10.5 vs. 17.1%) and nondominant (10.2 vs. 18.3%) torso rotational strength and the medicine ball hitter's throw (3.0 vs. 10.6%), group 2 showed significantly greater increases in all 3 variables than group 1. Furthermore, both groups made significant increases in predicted 1RM parallel squat and bench press after 4, 8, and 12 weeks of training; however, there were no differences between groups. These data indicate that performing a 12-week medicine ball training program in addition to a stepwise periodized resistance training program with bat swings provided greater sport-specific training improvements in torso rotational and sequential hip-torso-arm rotational strength for high school baseball players.     

The effects of combined ballistic and heavy resistance training on maximal lower- and upper-body strength in recreationally trained men

The purpose of the present study was to investigate the additive effects of ballistic training to a traditional heavy resistance training program on upper- and lower-body maximal strength. Seventeen resistance-trained men were randomly assigned to 1 of 2 groups: (i) a combined ballistic and heavy resistance training group (COM; age = 21.4 +/- 1.7 years, body mass = 82.7 +/- 15.1 kg) or (ii) a heavy resistance training group (HR; age = 20.1 +/- 1.2 years, body mass = 81.0 +/- 9.2 kg) and subsequently participated in an 8-week periodized training program. Training was performed 3 days per week, that is, 6-8 exercises per workout (6-8 traditional exercises for HR; 4-6 traditional + 2 ballistic exercises in COM) for 3-8 repetitions. A significant increase in 1-repetition maximum (1RM) squat was shown in both groups (COM = 15.2%; HR = 17.3%) with no difference observed between groups. However, 1RM bench press increased to a significantly greater extent (P = 0.04) in COM than HR (11.6% vs. 7.1%, respectively). For peak power attained during the jump squat, an interaction (P = 0.02) was observed where the 5.4% increase in COM and -3.2% reduction in HR were statistically significant. Nonsignificant increases were observed in peak plyometric push-up power in COM (8.5%) and HR (3.4%). Lean body mass increased significantly in both groups, with no between-group differences observed. The results of this study support the inclusion of ballistic exercises into a heavy resistance training program for increasing 1RM bench press and enhancing lower-body power.     

Running-specific, periodized strength training attenuates loss of stride length during intense endurance running

The purpose of this study was to determine the effects of a running-specific, periodized strength training program (performed over the specific period [8 weeks] of a 16-week macrocycle) on endurance-trained runners' capacity to maintain stride length during running bouts at competitive speeds. Eighteen well-trained middle-distance runners completed the study (personal bests for 1500 and 5000 m of 3 minutes 57 seconds +/- 12 seconds and 15 minutes 24 seconds +/- 36 seconds). They were randomly assigned to each of the following groups (6 per group): periodized strength group, performing a periodized strength training program over the 8-week specific (intervention) period (2 sessions per week); nonperiodized strength group, performing the same strength training exercises as the periodized group over the specific period but with no week-to-week variations; and a control group, performing no strength training at all during the specific period. The percentage of loss in the stride length (cm)/speed (m.s) (SLS) ratio was measured by comparing the mean SLS during the first and third (last) group of the total repetitions, respectively, included in each of the interval training sessions performed at race speeds during the competition period that followed the specific period. Significant differences (p < 0.05) were found in mean percentage of SLS loss between the 3 study groups, with the periodized strength group showing no significant SLS change (0.36 +/- 0.95%) and the 2 other groups showing a moderate or high SLS loss (-1.22 +/- 1.5% and -3.05 +/- 1.2% for the nonperiodized strength and control groups, respectively). In conclusion, periodized, running-specific strength training minimizes the loss of stride length that typically occurs in endurance runners during fatiguing running bouts.     

The effectiveness of resisted jump training on the VertiMax in high school athletes

Resisted jumping devices and resisted plyometric training have become more common in recent years. The effectiveness of such training has yet to be determined among high school athletes. Sixty-four high school athletes (50 boys and 14 girls) from a variety of sports were divided into 2 groups and participated in a training intervention that differed only by the use of the VertiMax jump trainer in 1 group. Lower-body power was tested before and after the intervention and compared statistically for differences between the groups. Athletes from both groups followed a periodized training program with resistance exercises performed 2 or 3 days per week, and sprint and plyometric training (i.e., training control group) or sprint, plyometric, and VertiMax training (i.e., VertiMax group) 1 or 2 days per week, for 12 total weeks. In addition to the traditional compound lower-body lifts and equated sprint work, the VertiMax group performed supplementary exercises on the VertiMax training apparatus. The average improvement in power observed in the training control group was 49.50 +/- 97.83 W, and the increase in power in the VertiMax group was 217.14 +/- 99.21 W. The differences in power after the test and improvements in power with training were found to differ between the groups (P < 0.05) and favored the VertiMax training group. Combined with previous research with college athletes, these data show the added effectiveness of resisted jump training on the VertiMax among athletes for the development of lower-body power.     

Physiological profiles and performance predictors of a women's NCAA rowing team

We described the physiological profiles of rowers (N = 16; age = 20.1 +/- 1.4 years, weight = 78.6 +/- 9.5 kg, height = 177.5 +/- 3.1 cm) of the top 2 varsity boats on an NCAA women's crew and determined whether physiological measures predict boat assignment as determined by the head coach. Eight participants were members of the top varsity boat (1V) and 8 competed at a lower level (2V). Expired gases were collected while subjects completed the U.S. National Team VO(2)max (3-minute stages) and 2 kilometer (2K) time trial rowing ergometer protocols. Heart rates (HR) and blood lactates were measured before, during, and after each test. The VO(2)max and blood lactate at stage 2 of the VO(2)max test were used to predict boat assignment. Average (+/-SD) VO(2)max was 3.86 +/- 0.40 L.min(-1). The 2K times averaged 453.0 +/- 10.5 seconds. Subjects used approximately 96% of VO(2)max and 98% of HR(max) during the 2K time trials. Neither VO(2)max nor submaximal lactate were related to boat assignment. The VO(2) values during the 2K trial indicated that rowing economy differed among athletes. Results of physiological measures should help the coach individualize workouts of top performers.     

The combined effects of protein intake and resistance training on serum osteocalcin concentrations in strength and power athletes

The purpose of the present investigation was to examine the combined effects of protein intake and resistance training on a blood marker of bone osteogenesis, serum osteocalcin, in Division III football players. Thirty-three resistance-trained football players (age = 20.4 +/- 1.8 years; height = 180.9 +/- 7.0 cm; body mass = 97.2 +/- 12.6 kg) were evaluated on their protein intake and subsequently underwent 10 weeks of periodized heavy resistance training during the off season. Subjects were then placed into 1 of the following 3 groups based on relative protein intake and were instructed to maintain their diets throughout the experimental period: (a) low protein intake (<1.2 g per kilogram of body mass), (b) moderate protein intake (1.21 to 1.90 g per kilogram of body mass), or (c) high protein intake (>1.91 g per kilogram of body mass). Blood sampling occurred prior to and following the 10-week resistance training period to determine resting serum osteocalcin concentrations. A significant main effect was observed following training such that only the group who consumed <1.2 g per kilogram of body mass of protein shown significant elevations in serum osteocalcin in response to resistance training (26.8 +/- 6.4 to 33.4 +/- 6.6 ng.ml(-1)). In addition, absolute protein intake was significantly correlated to serum osteocalcin concentrations (r = 0.39). The results of the present investigation demonstrated relationships between protein intake and serum osteocalcin concentrations. In addition, the osteocalcin response to short-term resistance training appeared to be affected by protein intake.     

The effects of accentuated eccentric loading on strength, muscle hypertrophy, and neural adaptations in trained individuals

The purpose of this study was to compare the strength and neuromuscular adaptations for dynamic constant external resistance (DCER) training and dynamic accentuated external resistance (DAER) training (resistance training employing an accentuated load during eccentric actions). Male subjects active in resistance training were assigned to either a DCER training group (n = 10) or a DAER training group (n = 8) for 9 weeks. Subjects in the DCER group performed 4 sets of 10 repetitions with a load of 75% concentric 1 repetition maximum (RM). Subjects in the DAER group performed 3 sets of 10 repetitions with a concentric load of 75% of 1RM and an eccentric load of approximately 120% of concentric 1RM. Three measures reflecting adaptation of elbow flexors and extensors were recorded pretraining and posttraining: concentric 1RM, muscle cross-sectional area (CSA), and specific tension. Strength was assessed at midtraining periods. No significant changes in muscle CSA were observed in either group. Both training groups experienced significant increases in concentric 1RM and specific tension of both the elbow flexors and extensors, but compared with DCER training, DAER training produced significantly greater increases in concentric 1RM of the elbow extensors. These results suggest that, for some exercises, DAER training may be more effective than DCER training in developing strength within a 9-week training phase. However, for trained subjects, neither protocol is effective in eliciting muscle hypertrophy.     

The effects of ten weeks of resistance and combined plyometric/sprint training with the Meridian Elyte athletic shoe on muscular performance in women

The purpose of this investigation was to examine the combined effects of resistance and sprint/plyometric training with or without the Meridian Elyte athletic shoe on muscular performance in women. Fourteen resistance-trained women were randomly assigned to one of 2 training groups: (a) an athletic shoe (N = 6) (AS) group or (b) the Meridian Elyte (N = 8) (MS) group. Training was performed for 10 weeks and consisted of resistance training for 2 days per week and 2 days per week of sprint/plyometric training. Linear periodized resistance training consisted of 5 exercises per workout (4 lower body, 1 upper body) for 3 sets of 3-12 repetition maximum (RM). Sprint/plyometric training consisted of 5-7 exercises per workout (4-5 plyometric exercises, 40-yd and 60-yd sprints) for 3-6 sets with gradually increasing volume (8 weeks) followed by a 2-week taper phase. Assessments for 1RM squat and bench press, vertical jump, broad jump, sprint speed, and body composition were performed before and following the 10-week training period. Significant increases were observed in both AS and MS groups in 1RM squat (12.0 vs. 14.6 kg), bench press (6.8 vs. 7.4 kg), vertical jump height (3.3 vs. 2.3 cm), and broad jump (17.8 vs. 15.2 cm). Similar decreases in peak 20-, 40-, and 60-m sprint times were observed in both groups (20 m: 0.14 vs. 0.11 seconds; 40 m: 0.29 vs. 0.34 seconds; 60 m: 0.45 vs. 0.46 seconds in AS and MS groups, respectively). However, when sprint endurance (the difference between the fastest and slowest sprint trials) was analyzed, there was a significantly greater improvement at 60 m in the MS group. These results indicated that similar improvements in peak sprint speed and jumping ability were observed following 10 weeks of training with either shoe. However, high-intensity sprint endurance at 60 m increased to a greater extent during training with the Meridian Elyte athletic shoe.     

Effect of direct supervision of a strength coach on measures of muscular strength and power in young rugby league players

The purpose of the present study was to examine the influence of direct supervision on muscular strength, power, and running speed during 12 weeks of resistance training in young rugby league players. Two matched groups of young (16.7 +/- 1.1 years [mean +/- SD]), talented rugby league players completed the same periodized resistance-training program in either a supervised (SUP) (N = 21) or an unsupervised (UNSUP) (N = 21) environment. Measures of 3 repetition maximum (3RM) bench press, 3RM squat, maximal chin-ups, vertical jump, 10- and 20-m sprints, and body mass were completed pretest (week 0), midtest (week 6), and posttest (week 12) training program. Results show that 12 weeks of periodized resistance training resulted in an increased body mass, 3RM bench press, 3RM squat, maximum number of chin-ups, vertical jump height, and 10- and 20-m sprint performance in both groups (p < 0.05). The SUP group completed significantly more training sessions, which were significantly correlated to strength increases for 3RM bench press and squat (p < 0.05). Furthermore, the SUP group significantly increased 3RM squat strength (at 6 and 12 weeks) and 3RM bench press strength (12 weeks) when compared to the UNSUP group (p < 0.05). Finally, the percent increase in the 3RM bench press, 3RM squat, and chin-up(max) was also significantly greater in the SUP group than in the UNSUP group (p < 0.05). These findings show that the direct supervision of resistance training in young athletes results in greater training adherence and increased strength gains than does unsupervised training.     

The effects of combining elastic and free weight resistance on strength and power in athletes

This study was undertaken to determine whether combined elastic and free weight resistance (CR) provides different strength and power adaptations than free weight resistance (FWR) training alone. Forty-four young (age 20 +/- 1 years), resistance-trained (4 +/- 2 years' experience) subjects were recruited from men's basketball and wrestling teams and women's basketball and hockey teams at Cornell University. Subjects were stratified according to team, then randomly assigned to the control (C; n = 21) or experimental group (E; n = 23). Before and after 7 weeks of resistance training, subjects were tested for lean body mass, 1 repetition maximum back squat and bench press, and peak and average power. Both C and E groups performed identical workouts except that E used CR (i.e., elastic resistance) for the back squat and bench press, whereas the C group used FWR alone. CR was performed using an elastic bungee cord attached to a standard barbell loaded with plates. Elastic tension was accounted for in an attempt to equalize the total work done by each group. Statistical analyses revealed significant (P < 0.05) between-group differences after training. Compared with C, improvement for E was nearly three times greater for back squat (16.47 +/- 5.67 vs. 6.84 +/- 4.42 kg increase), two times greater for bench press (6.68 +/- 3.41 vs. 3.34 +/- 2.67 kg increase), and nearly three times greater for average power (68.55 +/- 84.35 vs. 23.66 +/- 40.56 watt increase). Training with CR may be better than FWR alone for developing lower and upper body strength, and lower body power in resistance-trained individuals. Long-term effects are unclear, but CR training makes a meaningful contribution in the short term to performance adaptations of experienced athletes.     

Resistance training and detraining effects on flexibility performance in the elderly are intensity-dependent

The present investigation attempted to determine whether resistance exercise intensity affects flexibility and strength performance in the elderly following a 6-month resistance training and detraining period. Fifty-eight healthy, inactive older men (65- 78 yrs) were randomly assigned to 1 of 4 groups: a control group (C, n = 10), a low-intensity resistance training group (LI, n = 14, 40% of 1 repetition maximum [1RM]), a moderate-intensity resistance training group (MI, n = 12, 60% of 1RM), or a high-intensity resistance training group (HI, n = 14, 80% of 1RM). Subjects in exercise groups followed a 3 days per week, whole-body (10 exercises, 3 sets per exercise) protocol for 24 weeks. Training was immediately followed by a 24-week detraining period. Strength (bench and leg press 1RM) and range of motion in trunk, elbow, knee, shoulder, and hip joints were measured at baseline and during training and detraining. Resistance training increased upper- (34% in LI, 48% in MI, and 75% in HI) and lower-body strength (38% in LI, 53% in MI, and 63% in HI) in an intensity-dependent manner. Flexibility demonstrated an intensity-dependent enhancement (3-12% in LI, 6-22% in MI, and 8-28% in HI). Detraining caused significant losses in strength (70-98% in LI, 44-50% in MI, and 27-29% in HI) and flexibility (90-110% in LI, 30-71% in MI, and 23-51% in HI) in an intensity-dependent manner. Results indicate that resistance training by itself improves flexibility in the aged. However, intensities greater than 60% of 1RM are more effective in producing flexibility gains, and strength improvement with resistance training is also intensity-dependent. Detraining seems to reverse training strength and flexibility gains in the elderly in an intensity-dependent manner.     

Arterial compliance of rowers: implications for combined aerobic and strength training on arterial elasticity

Regular endurance exercise increases central arterial compliance, whereas resistance training decreases it. It is not known how the vasculature adapts to a combination of endurance and resistance training. Rowing is unique, because its training encompasses endurance- and strength-training components. We used a cross-sectional study design to determine arterial compliance of 15 healthy, habitual rowers [50 +/- 9 (SD) yr, 11 men and 4 women] and 15 sedentary controls (52 +/- 8 yr, 10 men and 5 women). Rowers had been training 5.4 +/- 1.2 days/wk for 5.7 +/- 4.0 yr. The two groups were matched for age, body composition, blood pressure, and metabolic risk factors. Central arterial compliance (simultaneous ultrasound and applanation tonometry on the common carotid artery) was higher (P < 0.001) and carotid beta-stiffness index was lower (P < 0.001) in rowers than in sedentary controls. There were no group differences for measures of peripheral (femoral) arterial stiffness. The higher central arterial compliance in rowers was associated with a greater cardiovagal baroreflex sensitivity, as estimated during a Valsalva maneuver (r = 0.54, P < 0.005). In conclusion, regular rowing exercise in middle-aged and older adults is associated with a favorable effect on the elastic properties of the central arteries. Our results suggest that simultaneously performed endurance training may negate the stiffening effects of strength training.     

Effect of interrepetition rest intervals on weight training repetition power output

The purpose of this study was to determine the change in weight training repetition power output as a consequence of interrepetition rest intervals. Twenty-six elite junior male basketball and soccer players performed bench presses using a 6 repetition maximum (6RM) load. The power output for each repetition was recorded using a linear encoder sampling each 10 ms (100 Hz). Subjects were assigned to 1 of 3 intervention groups, differentiated by the arrangement of rest intervals within the 6 repetitions: 6 x 1 repetition with 20-second rest periods between each repetition (Singles); 3 x 2 repetitions with 50 seconds between each pair of repetitions (Doubles); or 2 x 3 repetitions with 100 seconds of rest between each 3 repetitions (Triples). A timer was used to ensure that the rest interval and duration to complete all interrepetition interventions was equated across groups (118 seconds). Significantly (p < 0.05) greater repetition power outputs (25-49%) were observed in the later repetitions (4-6) of the Singles, Doubles, and Triples loading schemes. Significantly greater total power output (21.6-25.1%) was observed for all interrepetition rest interventions when compared to traditional continuous 6RM total power output. No significant between-group differences were found (p = 0.96). We conclude that utilizing interrepetition rest intervals enables greater repetition and total power output in comparison to traditional loading parameters.     

Evaluation of muscle activity during a standardized shoulder resistance training bout in novice individuals

Momentary fatigue is an important variable in resistance training periodization programs. Although several studies have examined neuromuscular activity during single repetitions of resistance training, information is lacking in regard to neuromuscular fatigue indices throughout a full resistance training bout. The purpose of this study was to evaluate muscle activity during a shoulder resistance training bout with 15 repetitions maximum (RM) loadings in novice individuals. Twelve healthy sedentary women (age = 27-58 years; weight = 54-85 kg; height = 160-178 cm) were recruited for this study. Normalized electromyographic (nEMG) activity and median power frequency (MPF) of the upper, medial, and lower trapezius; the medial deltoid, infraspinatus, and serratus anterior was measured during 3 sets of 15RM during the exercises front raise, reverse flyes, shrugs, and lateral raise. For the majority of exercises, nEMG activity was high (>60% of maximal isometric contractions). From the first to the last repetition of each set nEMG-averaged for all muscles-increased 10. 0 ± 0.4% (p < 0.05) and MPF decreased -7.7 ± 0.5 Hz (p < 0.05). By contrast, nEMG activity and MPF were unchanged from the first to the third set (averaged for all muscles: 38.1 ± 23.6 vs. 47.6 ± 28.8% and 88.4 ± 21.3 vs. 82.1 ± 18.1 Hz, respectively). In conclusion, during a shoulder resistance training bout in novice individuals using 15RM loading muscle activity of the upper, medial, and lower trapezius, the medial deltoid, infraspinatus, and serratus anterior increased, and MPF decreased within each set-indicating momentary neuromuscular fatigue. By contrast, no such change was observed between the 3 sets. This indicates that momentary neuromuscular fatigue in shoulder resistance training is induced more efficiently within a set than between sets.