, and body fat percentage). Secondary DVs included maximal strength (back squat and deadlift) and resting metabolic rate (RMR). Participants Healthy, young, aspiring female physique athletes volunteered to participate in the study. To qualify, all participants were required to have resistance trained
Bill I. Campbell, Danielle Aguilar, Laurin Conlin, Andres Vargas, Brad Jon Schoenfeld, Amey Corson, Chris Gai, Shiva Best, Elfego Galvan and Kaylee Couvillion
Kris Beattie, Brian P. Carson, Mark Lyons and Ian C. Kenny
Maximum- and reactive-strength qualities both have important roles in athletic movements and sporting performance. Very little research has investigated the relationship between maximum strength and reactive strength. The aim of this study was to investigate the relationship between maximum-strength (isometric midthigh-pull peak force [IMTP PF]) and reactive-strength (drop-jump reactive-strength index [DJ-RSI]) variables at 0.3-m, 0.4-m, 0.5-m, and 0.6-m box heights. A secondary aim was to investigate the between- and within-group differences in reactive-strength characteristics between relatively stronger athletes (n = 11) and weaker athletes (n = 11). Forty-five college athletes across various sports were recruited to participate in the study (age, 23.7 ± 4.0 y; mass, 87.5 ± 16.1 kg; height, 1.80 ± 0.08 m). Pearson correlation results showed that there was a moderate association (r = .302–.431) between maximum-strength variables (absolute, relative, and allometric scaled PF) and RSI at 0.3, 0.4, 0.5 and 0.6 m (P ≤ .05). In addition, 2-tailed independent-samples t tests showed that the RSIs for relatively stronger athletes (49.59 ± 2.57 N/kg) were significantly larger than those of weaker athletes (33.06 ± 2.76 N/kg) at 0.4 m (Cohen d = 1.02), 0.5 m (d = 1.21), and 0.6 m (d = 1.39) (P ≤ .05). Weaker athletes also demonstrated significant decrements in RSI as eccentric stretch loads increased at 0.3-m through 0.6-m box heights, whereas stronger athletes were able to maintain their reactive-strength ability. This research highlights that in specific sporting scenarios, when there are high eccentric stretch loads and fast stretch-shortening-cycle demands, athletes’ reactive-strength ability may be dictated by their relative maximal strength, specifically eccentric strength.
Kenny Guex, Chantal Daucourt and Stéphane Borloz
In the field of sport rehabilitation, an easy, valid, and reliable assessment of maximal strength is crucial for efficient muscle rehabilitation. Classically, it is performed on fitness equipment that is not necessary available in the field. Thera-Band has developed elastic bands with different resistances depending on the color of the band and on the percentage of its stretch. This may allow testing maximal strength.
To determine validity and reliability of maximal-strength assessment of knee flexors and extensors using elastic bands.
Reliability and validity study.
22 healthy participants (31.3 ± 7.0 y, 175.5 ± 8.5 cm, 70.7 ± 12.9 kg).
Participants performed 2 maximal-strength assessments, separated by 7 d, of the knee flexors and extensors using elastic bands. After the 2nd trial, a maximal concentric isokinetic test at 60°/s was performed.
Main Outcome Measures:
Correlations between 1-repetition maximum using elastic bands and peak torque on an isokinetic dynamometer were used to determine the validity of the proposed method, while ICC, CV, and SEM were used to determine reliability between the 1st and 2nd trials.
The validity of the proposed method was found to be very high (r = .93 for both knee flexors and extensors). The relative reliability was found to be very high (ICC = .98 and .99 for knee flexors and extensors, respectively), while absolute reliability was also very satisfying (CV = 3.44% and 2.33%; SEM = 1.70 and 2.16 kg for knee flexors and extensors, respectively).
Thera-Band is a valid and reliable alternative to the use of fitness equipment to test maximal strength of the knee flexors and extensors in healthy subjects. The ease of use, accessibility, and low cost of elastic bands should allow regular assessment during the rehabilitation process.
Kevin M. Carroll, Jake R. Bernards, Caleb D. Bazyler, Christopher B. Taber, Charles A. Stuart, Brad H. DeWeese, Kimitake Sato and Michael H. Stone
Resistance training (RT) has repeatedly shown the capability to enhance physical performance characteristics, such as maximal strength 1 – 4 and rate of force development (RFD). 5 Maximal strength and RFD are critically important for athletes, particularly in strength–power sports. 6 , 7
Bettina Karsten, Liesbeth Stevens, Mark Colpus, Eneko Larumbe-Zabala and Fernando Naclerio
To investigate the effects of a sport-specific maximal 6-wk strength and conditioning program on critical velocity (CV), anaerobic running distance (ARD), and 5-km time-trial performance (TT).
16 moderately trained recreational endurance runners were tested for CV, ARD, and TT performances on 3 separate occasions (baseline, midstudy, and poststudy).
Participants were randomly allocated into a strength and conditioning group (S&C; n = 8) and a comparison endurance-trainingonly group (EO; n = 8). During the first phase of the study (6 wk), the S&C group performed concurrent maximal strength and endurance training, while the EO group performed endurance-only training. After the retest of all variables (midstudy), both groups subsequently, during phase 2, performed another 6 wk of endurance-only training that was followed by poststudy tests.
No significant change for CV was identified in either group. The S&C group demonstrated a significant decrease for ARD values after phases 1 and 2 of the study. TT performances were significantly different in the S&C group after the intervention, with a performance improvement of 3.62%. This performance increase returned close to baseline after the 6-wk endurance-only training.
Combining a 6-wk resistance-training program with endurance training significantly improves 5-km TT performance. Removing strength training results in some loss of those performance improvements.
Daniël M. van Leeuwen, Fabian van de Bunt, Cornelis J. de Ruiter, Natasja M. van Schoor, Dorly J.H. Deeg and Kaj S. Emanuel
with any decline in joint functioning. No differences in maximal strength, VA, and fatigability were observed between the groups. The participants were relatively fit due to the inclusion criteria, most specifically the ability to climb stairs, which is illustrated by good outcomes for several tests
Jerry L. Mayhew, Sidney Palmer Hill, Melissa D. Thompson, Erin C. Johnson and Lyndsay Wheeler
The purpose of this study was to evaluate the effectiveness of repetitions to fatigue (RTF) using absolute and relative muscle-endurance performances to estimate 1-repetition-maximum (1-RM) bench-press performance in high school male athletes.
Members of high school athletic teams (n = 118, age = 16.5 ± 1.1 y, weight = 82.7 ± 18.7 kg) were tested for 1-RM bench press and RTF with an absolute load of 61.4 kg and a relative load that produced 7 to 10 RTF (7- to 10-RM). All participants had completed a minimum of 4 wk of resistance training before measurement.
All 7- to 10-RM-prediction equations had higher correlations between predicted and actual 1-RM (r > .98) than the 61.4-kg absolute-load equation (r = .95). Despite the high correlations, only 3 of 11 equations produced predicted values that were nonsignificantly different from actual 1-RM. The best 7- to 10-RM equation predicted 65% of the athletes’ performances within ±4.5 kg of their actual 1-RM. The addition of simple anthropometric dimensions did not increase the validity correlations or decrease the prediction errors.
The 7- to 10-RM method can provide an accurate method of estimating strength levels for adjusting loads in a training program and is more accurate for predicting 1-RM bench press in high school athletes than the 61.4-kg repetition method.
Leyre Gravina, Frankie F. Brown, Lee Alexander, James Dick, Gordon Bell, Oliver C. Witard and Stuart D.R. Galloway
Omega-3 fatty acid (n-3 FA) supplementation could promote adaptation to soccer-specific training. We examined the impact of a 4-week period of n-3 FA supplementation during training on adaptations in 1RM knee extensor strength, 20-m sprint speed, vertical jump power, and anaerobic endurance capacity (Yo-Yo test) in competitive soccer players. Twenty six soccer players were randomly assigned to one of two groups: n-3 FA supplementation (n-3 FA; n = 13) or placebo (n = 13). Both groups performed two experimental trial days. Assessments of physical function and respiratory function were conducted pre (PRE) and post (POST) supplementation. Training session intensity, competitive games and nutritional intake were monitored during the 4-week period. No differences were observed in respiratory measurements (FEV1, FVC) between groups. No main effect of treatment was observed for 1RM knee extensor strength, explosive leg power, or 20 m sprint performance, but strength improved as a result of the training period in both groups (p < .05). Yo-Yo test distance improved with training in the n-3 FA group only (p < .01). The mean difference (95% CI) in Yo-Yo test distance completed from PRE to POST was 203 (66–340) m for n-3 FA, and 62 (-94–217) m for placebo, with a moderate effect size (Cohen’s d of 0.52). We conclude that 4 weeks of n-3 FA supplementation does not improve strength, power or speed assessments in competitive soccer players. However, the increase in anaerobic endurance capacity evident only in the n-3 FA treatment group suggests an interaction that requires further study.
Cyril Genevois, Philippe Berthier, Vincent Guidou, Franck Muller, Boris Thiebault and Isabelle Rogowski
In women's handball, the large numbers of throws and passes make the shoulder region vulnerable to overuse injuries. Repetitive throwing motions generate imbalance between shoulder internal- and external-rotator muscles. It has not yet been established whether sling-based training can improve shoulder external-rotator muscle strength.
This study investigated the effectiveness of a 6-wk strengthening program in improving shoulder functional profile in elite female high school handball players.
National elite handball training center.
25 elite female high school handball players.
The program, completed twice per week for 6 wk, included sling-based strengthening exercises using a suspension trainer for external rotation with scapular retraction and scapular retraction alone.
Maximal shoulder external- and internal-rotation strength, shoulder external- and internal-rotation range of motion (ROM), and maximal throwing velocity were assessed preintervention and postintervention for dominant and nondominant sides.
After sling training, external- and internal-rotation strength increased significantly for both sides (P ≤ .001, and P = .004, respectively), with the result that there was no significant change in external- and internal-rotation strength ratios for either the dominant or the nondominant shoulder. No significant differences were observed for external-rotation ROM, while internal-rotation ROM decreased moderately, in particular in the dominant shoulder (P = .005). Maximal throwing velocity remained constant for the dominant arm, whereas a significant increase was found for the nondominant arm (P = .017).
This 6-wk strengthening program was effective in improving shoulder external-rotator muscle strength but resulted in a decrease in the ROM in shoulder internal rotation, while throwing velocity remained stable. Adding a stretching program to this type of sling-based training program might help avoid potential detrimental effects on shoulder ROM.
Kamila Grandolfi, Vandre Sosciarelli and Marcos Polito
Purpose: To compare performance in successive 1-repetition maximum (1RM) tests with the load known or unknown. Methods: Thirty-two resistance-trained men were randomly divided into 2 groups: load blinding (BLI; n = 16; age 28.1 [6.9] y, body mass 83.1 [11.5] kg, height 175.3 [5.8] cm) and load nonblinding (nBLI; n = 16; age 27.7 [4.1] y, body mass 83.2 [12.8] kg, height 178.7 [7.3] cm). The groups performed a 1RM test during 4 days (with an interval of 24–48 h) in the horizontal bench press with free weight. Results: In the BLI, there were no significant changes throughout the tests, with a difference of 1.6% between the first and fourth 1RM tests. In the nBLI, there was a significant interaction with time, and the values of the second (P = .03), third (P = .02), and fourth (P = .01) tests were higher than the first test; in addition, the fourth test was significantly higher than the second test (P = .02). The percentage difference between the last and first 1RM tests was 7.1%. The comparison between the groups demonstrated differences in the third (P = .04) and fourth (P = .02) tests with higher values in the nBLI. The intraclass correlation coefficient between the first and fourth 1RM tests was .93 for the BLI and .91 for the nBLI. Conclusion: BLI does not influence 1RM testing in the bench press exercise.