Self-efficacy, Effort, and Performance Perceptions Enhance Psychological Responses to Strength Training in National Collegiate Athletic Association Division I Athletes.

ABSTRACT: Biscardi, LM, Miller, AD, Andre, MJ, and Stroiney, DA. Self-efficacy, effort, and performance perceptions enhance psychological responses to strength training in National Collegiate Athletic Association Division I athletes. J Strength Cond Res 38(5): 898-905, 2024-This study examined the effect of self-efficacy, effort, and perceived performance on positive well-being (PWB) and psychological distress (PD) following high-intensity resistance training sessions in collegiate student-athletes. An observational field study design was used to collect data before and after resistance training sessions in a 4-week preseason strength training block. A multilevel model assessed day-level and person-level variance in acute PWB and PD. Interaction terms were also tested at the day level. Alpha was set at 0.05. Within a 4-week training block, training session intensity did not predict changes in acute psychological responses. After controlling for an athlete's preexercise psychological state, higher self-efficacy, daily effort, and perceived performance predicted higher PWB and lower PD following training (p < 0.05). Self-efficacy moderated the relationships of daily effort and performance with PD (p < 0.05). When athletes experienced lower self-efficacy, producing a higher effort and perceiving better performance reduced the negative psychological response. These findings highlight the important mediating role of cognitive variables in the acute psychological response to high-intensity resistance training. Coaches should identify and mitigate low cognitive states to facilitate a positive psychological response to resistance training. This strategy promotes a positive psychological response without altering training prescription.

Acute Effects of a Caffeine-Containing Supplement on Anaerobic Power and Subjective Measurements of Fatigue in Recreationally Active Men.

Hahn, CJ, Jagim, AR, Camic, CL, and Andre, MJ. Acute effects of a caffeine-containing supplement on anaerobic power and subjective measurements of fatigue in recreationally active men. J Strength Cond Res 32(4): 1029-1035, 2018-Studies show mixed results for the effects of caffeine on performance, warranting further investigation. The purpose of this study was to examine the acute effects of a caffeine-containing supplement on anaerobic power and subjective measurements of fatigue during resisted sprinting on men. Fourteen recreationally active men (N = 14; [mean ± SD], age: 21.0 ± 0.7 years, height: 178.5 ± 5.1 cm, body mass: 77.3 ± 9.6 kg, and percent body fat: 12.6 ± 4.8%) participated in a double-blind, placebo-controlled, within-subject crossover design study. The first visit required each participant to complete 3 sets of practice sprints on a nonmotorized treadmill ranging from 10 to 20 seconds. During the second visit, participants completed 5 more practice sprints ranging from 15 to 25 seconds. During the third and fourth visits, participants ingested one serving of a caffeine-containing or placebo beverage (the opposite beverage was consumed during the fourth visit), rested for 20 minutes, and completed a dynamic warm-up before sprinting. Anaerobic power was assessed using a countermovement vertical jump and nonmotorized treadmill sprint test. Psychological variables were scored using a 5-point Likert scale. No significant (p ≤ 0.05) differences were observed between conditions for average (p = 0.22) or peak power (p = 0.43). Both conditions resulted in a significant increase in fatigue, although the increase was less for the caffeine condition (caffeine [INCREMENT] = 0.93 and placebo [INCREMENT] = 1.71). These findings indicated that the caffeine-containing supplement improved perceived measures of fatigue but not power indices assessed through vertical jump or nonmotorized treadmill sprinting. The consumption of a caffeine beverage may be beneficial for reducing perceived fatigue during acute anaerobic exercise, particularly when repeated sprints are used.

Accuracy of a vertical jump contact mat for determining jump height and flight time.

Several devices are available to measure vertical jump (VJ) height based on flight time, VJ reach height, or ground reaction forces. The purpose of this study was to determine the accuracy of a VJ mat for measuring flight time and VJ height compared with a VJ tester or a force plate. Seventeen men and 18 women (X ± SD; age = 20.9 ± 0.7 years, height = 176.1 ± 0.9 cm, weight = 72.6 ± 13.5 kg) served as subjects. Subjects performed counter-movement vertical jumps while standing on both a force plate (1,000 Hz) and a VJ mat. A Vertec VJ tester was used to measure jump reach. Compared with the force plate, the VJ mat reported greater VJ height (VJ mat = 0.50 ± 0.12 m, force plate = 0.34 ± 0.10 m) and flight time (VJ mat = 0.629 ± 0.078 seconds, force plate = 0.524 ± 0.077 seconds). Comparison of VJ heights from the VJ mat and the Vertec revealed no significant differences (Vertec = 0.48 ± 0.11 m). Regression analyses indicated strong relationships between testing methods and suggested that high VJ performances may be underestimated with the VJ mat. This particular VJ mat compared favorably with the Vertec but not the force plate. It seems that the different flight times derived from the VJ mat may permit the VJ mat to be in closer agreement with VJ heights from the Vertec. Also, the VJ mat may not be an appropriate tool for assessing high VJ performances (i.e., ≥0.70 m; ≈28 inches). Practitioners and researchers using similar VJ mats may not obtain accurate flight times and may underestimate high performers.

Determination of friction and pulling forces during a weighted sled pull.

Pulling or pushing weighted sleds has been included in various exercise programs. Coaches and researchers may wish to calculate work performed or estimate forces during these exercises, which would involve calculating coefficients of friction: static friction coefficient (µs) and dynamic friction coefficient (µd). The purpose of this study was to establish a reliable method for determining µs, µd, and pulling forces while pulling a weighted sled with different loads to quantify horizontal forces and work performed for training, assessment, and/or research. A nylon tether was attached to a sled-mounted force transducer, and a winch was used to pull the tethered sled at a constant velocity for 20 seconds. Three different loads were pulled: 44.8 kg (the unloaded weight of the sled), 90.0 kg (44.8 kg sled with an additional load of 45.2 kg), and 136.2 kg (44.8 kg sled with an additional load of 91.4 kg). Each load was pulled 10 times using the winch for a total of 30 trials. The static friction coefficient (mean ± SD) was 0.47 ± 0.01 (coefficient of variation [CV] = 2.2%), 0.42 ± 0.01 (CV = 3.0%), and 0.39 ± 0.01 (CV = 2.7%), whereas dynamic friction coefficient (mean ± SD) was 0.35 ± 0.01 (CV = 1.6%), 0.33 ± 0.01 (CV = 3.7%), 0.31 ± 0.00 (CV = 1.0%) for 44.8, 90.0, and 136.2 kg, respectively (p < 0.01). When all trials and loads were combined, µs = 0.43 ± 0.04 and µd = 0.33 ± 0.02 with CV of 8.3 and 5.6%, respectively. The friction coefficients determined in this study were very repeatable, as indicated by the low CV. Coaches, athletes, and researchers who wish to determine µs and µd for their own specific equipment and surfaces can use the methods described here to do so.

A reliable method for assessing rotational power.

Rotational core training is said to be beneficial for rotational power athletes. Currently, there has been no method proposed for the reliable assessment of rotational power. Therefore, our purpose was to determine the test-retest reliability of kinetic and kinematic rotational characteristics of a pulley system when performing a rotational exercise of the axial skeleton in the transverse plane to find out if this would be a reliable tool for evaluating rotational power. Healthy, college-aged men (n = 8) and women (n = 15) reported for 3 testing sessions. The participants were seated on a box, and they held the handle with both arms extended in front of their body, starting their motion with their torso rotated toward the machine. All the participants rotated their torso forcefully until they reached 180° of rotation, and they then slowly returned to the starting position, 3 times per trial, with 3 loads: 9% body weight (BW), 12% BW, and 15% BW. The repetition with the greatest power for each trial for each load was analyzed. The mean peak power repetition (watts) for all the subjects was 20.09 ± 7.16 (9% BW), 26.17 ± 8.6 (12% BW), and 30.74 ± 11.022 (15% BW) in the first training session and 22.3 ± 8.087 (9% BW), 28.7 ± 11.295 (12% BW), and 33.52 ± 12.965 (15% BW) in the second training session with intraclass correlation coefficients of 0.97 (9%BW), 0.94 (12%BW), and 0.95 (15%BW). When the participants were separated by sex, there were no significant differences between groups. Based on these results, it was found that a pulley system and an external dynamometer can be used together as a reliable research tool to assess rotational power.

Appropriate loads for peak-power during resisted sprinting on a non-motorized treadmill.

The purpose of this study was to determine the load which allows the highest peak power for resisted sprinting on a non-motorized treadmill and to determine if other variables are related to individual differences. Thirty college students were tested for vertical jump, vertical jump peak and mean power, 10 m sprint, 20 m sprint, leg press 1 RM, leg press 1 RM relative to body weight, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM. Participants performed eight resisted sprints on a non-motorized treadmill, with increasing relative loads expressed as percent of body weight. Sprint peak power was measured for each load. Pearson correlations were used to determine if relationships between the sprint peak power load and the other variables were significant. The sprint peak power load had a mode of 35% with 73% of all participants having a relative sprint peak power load between 25-35%. Significant correlations occurred between sprint peak power load and body weight, lean body mass, vertical jump peak and mean power, leg press 1 RM, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM (r = 0.44, 0.43, 0.39, 0.37, 0.47, 0.39, 0.46, and 0.47, respectively). Larger, stronger, more powerful athletes produced peak power at a higher relative load during resisted sprinting on a non-motorized treadmill.

Upper-body muscular endurance in female university-level modern dancers: a pilot study.

Physical demands vary among dance styles, and injury patterns differ accordingly. Modern dance tends to be high in upper-body demands, and university-level female modern dancers are suggested to be at high risk for upper-body injury. Low muscular endurance is a known injury risk factor. Whether modern dancers have different upper-body muscular endurance than non-dancers is unclear. Thus, the purpose of this study was to compare upper-body endurance in female university-level modern dancers (n = 17) and physically active non-dancers (n = 15), using the modified push-up test. Pearson-correlations examined relationships between anthropometrics and push-ups. Multiple regression analyses were used to determine whether anthropometrics and physical activity could predict push-up scores. One-way ANOVAs compared upper-body endurance (number of push-ups) and physical activity between groups (p < 0.05). Except for height (r = -.37), no variables were related to push-ups. Neither anthropometrics nor physical activity were able to predict push-up scores (p = 0.25). Despite dancers being more active/day (3.6 ± 1.9 vs. 0.9 ± 0.4 hrs/day, p < 0.001), more times per week (5.4 ± 1.2 vs. 4.0 ± 1.8, p = 0.02), and having greater overall physical activity volumes (20.4 ± 11.4 vs. 3.3 ± 2.5 hrs/week, p < 0.001) than non-dancers, both groups had similar upper-body endurance (22.2 ± 8.6 vs. 19.9 ± 8.2, p = 0.44). A probable explanation for this similarity exists in the lack of physical activity beyond dance itself performed by the dancers; our preliminary work suggests that modern dance alone may not produce upper-body muscle endurance gains. Hence, it is suggested that modern dancers should engage in strength and conditioning training programs to enhance upper-body endurance.