Jerry L. Mayhew

The aim of this study was to evaluate prediction equations to estimate 1RM in different exercises in older men and women with osteopenia/osteoporosis. Forty well-trained older women and men (73 ± 8 years) with osteopenia/osteoporosis performed 1RM dynamic and isometric maximum strength tests on resistance devices. In addition, each participant performed repetitions-to-fatigue (RTF) in the 5–8RM, 9–12RM, and 13–16RM zones. After evaluating the predictive performance of available 1RM prediction equations from the literature, new prediction equations were developed for all seven exercises. One of the available equations that focus on postmenopausal women already acceptably predicted 1RM from RTF for all but one exercise. Nevertheless, new exercise-specific prediction equations based on a cubic polynomial most accurately predict 1RM from RTF in the 5–8 reps range with mean absolute differences between predicted and actual 1RM of 3.7 ± 3.7% (leg-press) to 6.9 ± 5.5% (leg flexion) that is roughly within the acceptable coefficient of variation. For some exercises, the inclusion of the isometric maximum strength tests slightly increases the prediction performance of the 5–8RM. In conclusion, the present prediction equation accurately estimates 1RM in trained, older women and men with osteopenia/osteoporosis. Further evaluation of this new equation is warranted to determine its applicability to different age groups and populations.

Muscular strength and hypertrophy following resistance training may be obtained in different degrees depending on the approach performed. This study was designed to compare the responses of the biceps brachii to two preacher curl exercises, one performed on a cable-pulley system (CAB; in which a greater torque was applied during the exercise when elbows were flexed and biceps shortened) and one performed with a barbell (BAR; in which greater torque was applied when the elbows were extended and biceps stretched). Thirty-five young adults (CAB: 13 men, 5 women; BAR: 12 men, 5 women; age = 24 ± 5 years) performed a resistance training program three times per week for 10 weeks, with preacher curl exercises performed in three sets of 8–12 repetitions. Outcomes measured included elbow flexion peak isokinetic torque at angles of 20°, 60°, and 100° (considering 0° as elbow extended), and biceps brachii thickness (B-mode ultrasound). Following the training period, there were significant increases for both groups in elbow flexion peak torque at the 20° (CAB: 30%; BAR = 39%; p = 0.046), 60° (CAB: 27%; BAR = 32%; p = 0.874), and 100° (CAB: 17%; BAR = 19%; p = 0.728), and biceps brachii thickness (CAB: 7%; BAR = 8%; p = 0.346). In conclusion, gains in muscular strength were greater for BAR only at longer muscle length, whereas hypertrophy was similar regardless of whether torque emphasis was carried out in the final (CAB) or initial (BAR) degrees of the range of motion of the preacher curl in young adults.

Heinecke, ML, Mauldin, ML, Hunter, ML, Mann, JB, and Mayhew, JL. Relationship of barbell and dumbbell repetitions with one repetition maximum bench press in college football players. J Strength Cond Res 35(2S): S66–S71, 2021—Dumbbell training to augment barbell training is gaining popularity. However, information is lacking that details the compatibility of strength and endurance between dumbbell and barbell performances in the same exercise. Therefore, the purposes of this study were to compare the similarity of muscular endurance performance between dumbbell and barbell exercises and to assess the accuracy of predicting one repetition maximum (1RM) barbell bench press from barbell and dumbbell repetitions to fatigue (RTF). College football players (n = 40) performed 1RM barbell bench press and RTF with a 90.9-kg barbell. On separate days, unilateral (45.5 kg) and bilateral dumbbell (90.9 kg) RTF were performed. Barbell RTF (13.8 ± 9.2) were significantly greater (effect size [ES] = 0.14) than bilateral dumbbell RTF (12.5 ± 9.5) but highly correlated (r = 0.96). Unilateral dumbbell RTF were significantly greater (ES = 0.13) for dominant hand (10.8 ± 10.1) than nondominant hand (9.5 ± 9.7) but highly correlated (r = 0.97). Prediction of 1RM barbell bench press was equally effective using a constant weight barbell (r = 0.90) or equivalent weight bilateral dumbbells (r = 0.87) with total errors of 7.3 and 8.2%, respectively. Barbell and dumbbell repetitions with equivalent weights place a similar demand on the upper-body musculature for training and testing purposes in football athletes.

Est (I-Test) and 3-cone drill (3-CD) are widely used in football to assess quickness in change of direction. Likewise, the 10-yard (yd) sprint, a test of sprint acceleration, is gaining popularity for testing physical competency in football players. Despite their frequent use, little information exists on the relationship between agility and sprint tests as well the reliability and degree of change necessary to indicate meaningful improvement resulting from training. The purpose of this study was to determine the reliability and smallest worthwhile difference (SWD) of the I-Test and 3-CD and the relationship of sprint acceleration to their performance. Division-I football players (n = 64, age = 20.5 ± 1.2 years, height = 185.2 ± 6.1 cm, body mass = 107.8 ± 20.7 kg) performed duplicate trials in each test during 2 separate weeks at the conclusion of a winter conditioning period. The better time of the 2 trials for each week was used for comparison. The 10-yd sprint was timed electronically, whereas the I-Test and 3-CD were hand timed by experienced testers. Each trial was performed on an indoor synthetic turf, with players wearing multicleated turf shoes. There was no significant difference (p > 0.06) between test weeks for the I-Test (4.53 ± 0.35 vs. 4.54 ± 0.31 seconds), 3-CD (7.45 ± 0.06 vs. 7.49 ± 0.06 seconds), or 10-yd sprint (1.85 ± 0.12 vs. 1.84 ± 0.12 seconds). The intraclass correlation coefficients (ICC) for 3-CD (ICC = 0.962) and 10-yd sprint (ICC = 0.974) were slightly higher than for the I-Test (ICC = 0.914). These values lead to acceptable levels of the coefficient of variation for each test (1.2, 1.2, and 1.9%, respectively). The SWD% indicated that a meaningful improvement due to training would require players to decrease their times by 6.6% for I-Test, 3.7% for 3-CD, and 3.8% for 10-yd sprint. Performance in agility and short sprint tests are highly related and reliable in college football players, providing quantifiable parameters for judging true change in performance as opposed to random measurement variation in college football players....

Mayhew, JL, Brechue, WF, Smith, AE, Kemmler, W, Lauber, D, and Koch, AJ. Impact of testing strategy on expression of upper-body work capacity and one repetition maximum prediction after resistance training in college-aged men and women. J Strength Cond Res 25(10): 2796–2807, 2011—The purpose of this study was to assess the effect of resistance training on upper-body muscular strength and the expression of work capacity and muscular endurance. In addition, a training-induced change in the relationship between muscular strength and endurance was assessed by testing changes in the accuracy of using endurance repetitions to predict 1 repetition maximum (1RM) bench press before and after training. College-aged men (n = 85) and women (n = 62) completed a 12-week linear periodization resistance training program. Before and after training, the subjects were assessed for 1RM and repetitions to fatigue (RTFs) with a submaximal load. After pretraining 1RM determination, the subjects were randomly assigned to perform RTFs at 65% 1RM (n = 74) or 90% 1RM (n = 73). Pretraining and posttraining RTFs were conducted at the same respective %1RM. Work capacity was determined from repetition weight × RTF. After training, there was a significant increase in 1RM in both men (∼14%) and women (∼23%). Posttraining RTF was not different from pretraining RTF at 65 %1RM (18.2 ± 5.1 and 19.0 ± 6.0, respectively) but was significantly reduced in the 90% 1RM group (6.1 ± 3.6 vs. 4.5 ± 2.7, respectively). Likewise, there was a differential effect of training on the expression of work capacity, which increased in the 65 %1RM group (123 ± 155 kg-reps) but decreased in the 90% 1RM group (−62 ± 208 kg-reps); the effect was independent of gender within each testing group. In conclusion, the changes in muscular strength associated with resistance training produced an increase in work capacity when tested with a 65 %1RM load without a change in endurance. In contrast, both work capacity and endurance decreased when tested with 90% 1RM. Thus, the impact of strength training on work capacity and muscle endurance is specific to the load at which endurance testing is performed.