Eccentric Resistance Training in Youth: Perspectives for Long-Term Athletic Development

The purpose of this narrative review is to discuss the role of eccentric resistance training in youth and how this training modality can be utilized within long-term physical development. Current literature on responses to eccentric exercise in youth has demonstrated that potential concerns, such as fatigue and muscle damage, compared to adults are not supported. Considering the importance of resistance training for youth athletes and the benefits of eccentric training in enhancing strength, power, speed, and resistance to injury, its inclusion throughout youth may be warranted. In this review we provide a brief overview of the physiological responses to exercise in youth with specific reference to the different responses to eccentric resistance training between children, adolescents, and adults. Thereafter, we discuss the importance of ensuring that force absorption qualities are trained throughout youth and how these may be influenced by growth and maturation. In particular, we propose practical methods on how eccentric resistance training methods can be implemented in youth via the inclusion of efficient landing mechanics, eccentric hamstrings strengthening and flywheel inertia training. This article proposes that the use of eccentric resistance training in youth should be considered a necessity to help develop both physical qualities that underpin sporting performance, as well as reducing injury risk. However, as with any other training modality implemented within youth, careful consideration should be given in accordance with an individual's maturity status, training history and technical competency as well as being underpinned by current long-term physical development guidelines

Assessing strength and power in resistance training

Maximal Dynamic Strength is usually assessed either by the one repetition maximum test (1-RM) or by a repetition maximum test with submaximal loads, which requires the application of a formula to estimate the value of 1-RM. This value is needed to establish the objective of resistance training: such as maximum strength, endurance strength, and/or explosive strength. However, both 1-RM and submaximal tests are unable to highlight the changes produced on power and velocity. This manuscript summarizes and reviews several common strength testing protocols and proposes a novel approach that may offer greater insight to hierarchical muscle functionalit

Land based resistance training and youth swimming performance

Resistance training has been shown to have both performance-enhancing and injury reducing benefits in youth athletes. The benefits are somewhat overlooked by many swimming coaches, therefore the effects of a structured resistance training programme in highly trained youth swimmers was investigated. Nine competitive youth swimmers (age: 13 ± 1.1 years) underwent a 7 week dry-land resistance training programme. Swimming performance and other relevant physiological parameters were measured pre- and post-training. There was a small non-significant improvement in swimming performance following the 7 week training programme (100m freestyle; p > 0.05, ES = 0.26). Countermovement jump height (p < 0.05, ES = -1.26), back and leg strength (p < 0.05, ES = -1.85) and number of push ups completed in 60 s (p < 0.05, ES = -1.86) all significantly improved. Although the resistance training programme did not significantly improve swimming performance, other physiological parameters, important for success in the pool, did significantly improve. It may be that an adaptation period is needed so the swimmers can learn to efficiently apply their increased force in the water

The effects of Bodymax high-repetition resistance training on measures of body composition and muscular strength in active adult women

This is the author's PDF version of an article published in Journal of strenght and conditioning research in 2003. The definitive version is available at http://www.nsca-jscr.orgThe purpose of this study was to investigate the effects of a light, high-repetition resistance-training program on skinfold thicknesses and muscular strength in women. Thirty-nine active women (mean age 38.64 +/- 4.97 years) were randomly placed into a resistance-training group (RT; n = 20) or a control group (CG; n = 19). The RT group performed a resistance-training program called Bodymax for 1 hour, 3 d.wk(-1), which incorporated the use of variable free weights and high repetitions in a group setting. The CG group continued its customary aerobic training for 1 hour 3 d.wk(-1). Five skinfold and 7 muscular strength measures were determined pretraining and after 12 weeks of training. Sum of skinfolds decreased (-17 mm; p < 0.004) and muscular strength increased (+57.4 kg; p < 0.004) in the RT group. Effect sizes for individual skinfold sites and strength measures were "medium" and "high," respectively. Bodymax is an effective resistance-training program for reducing skinfold thickness and increasing muscular strength in active women. Therefore, women with a similar or lower-activity status should consider incorporating such training into their regular fitness programs

Kinetic Analysis of Lower Body Resistance Training Exercises

This study evaluated and compared the peak vertical ground reaction force (GRF) and rate of force development (RFD) for the eccentric and concentric phases of 4 lower body resistance training exercises, including the back squat, deadlift, step-up, and forward lunge. Sixteen women performed 2 repetitions of each of the 4 exercises at a 6 repetition maximum load. Kinetic data were acquired using a force platform. A repeated measures ANOVA was used to evaluate the differences in GRF between the exercises. Results revealed significant main effects for GRF both the eccentric (p ≤ 0.001) and concentric (p ≤ 0.001) phases. Significant main effects were also found for RFD for the eccentric (p ≤ 0.001) and concentric phases (p ≤ 0.001). Force and power requirements and osteogenic potential differ between these resistance training exercises

Effect of Hydro-Resistance Training on Bat Velocity

The purpose of this study was to determine the effect of hydro-resistance training on bat velocity during mimicked baseball swings in twenty-five female college students. Subjects were pre-tested for bat velocity and assigned to dry land (n = 8), water (n = 8), and control (n = 9) groups. The dry land group swung a 737 g (26 oz) Easton T1 Thunderstick baseball bat for three sets of 15 swings, three days per week, for eight weeks. The water group performed the swings in shoulder deep water. The dry land and water groups also participated in mandatory team general resistance training three days per week. The control group performed no bat swing or resistance-training regimens. Mean bat velocity was measured with an electronic eye-timing device. A 3 x 2 (Group x Time) ANOVA with repeated measures was used for statistical analysis, followed up with Tukey’s post hoc test. Bat velocity decreased significantly for the dry land and water groups (24.0 ± 3.6 m/s to 20.6 ± 4.1 m/s and 23.8 ± 3.5 to 18.8 ± 4.1 m/s, respectively). Bat velocity did not change for the control group (21.5 ± 3.0 m/s to 20.2 ± 2.1 m/s). We speculate that the decreased bat velocity in the dry land and water groups was caused by the mandatory team general resistance-training program

Task‐specific strength increases after lower‐limb compound resistance training occurred in the absence of corticospinal changes in vastus lateralis

Neural adaptations subserving strength increases have been shown to be task‐specific, but responses and adaptation to lower‐limb compound exercises such as the squat are commonly assessed in a single‐limb isometric task. This two‐part study assessed neuromuscular responses to an acute bout (Study A) and 4 weeks (Study B) of squat resistance training at 80% of one‐repetition‐maximum, with measures taken during a task‐specific isometric squat (IS) and non‐specific isometric knee extension (KE). Eighteen healthy volunteers (25 ± 5 years) were randomised into either a training (n = 10) or a control (n = 8) group. Neural responses were evoked at the intracortical, corticospinal and spinal levels, and muscle thickness was assessed using ultrasound. The results of Study A showed that the acute bout of squat resistance training decreased maximum voluntary contraction (MVC) for up to 45 min post‐exercise (−23%, P < 0.001). From 15–45 min post‐exercise, spinally evoked responses were increased in both tasks (P = 0.008); however, no other evoked responses were affected (P ≥ 0.240). Study B demonstrated that following short‐term resistance training, participants improved their one repetition maximum squat (+35%, P < 0.001), which was reflected by a task‐specific increase in IS MVC (+49%, P = 0.001), but not KE (+1%, P = 0.882). However, no training‐induced changes were observed in muscle thickness (P = 0.468) or any evoked responses (P = 0.141). Adjustments in spinal motoneuronal excitability are evident after acute resistance training. After a period of short‐term training, there were no changes in the responses to central nervous system stimulation, which suggests that alterations in corticospinal properties of the vastus lateralis might not contribute to increases in strength

Quasi-Isometric Cycling: A Case Study Investigation of a Novel Method to Augment Peak Power Output in Sprint Cycling

Purpose: Peak power output (PPO) is a determinant of sprint cycling performance and can be enhanced by resistance exercise that targets maximum strength. Conventional resistance training is not always suitable for elite cyclists because of chronic spinal issues; therefore, alternative methods to improve strength that concurrently reduce injury risk are welcome. In this case study, quasi-isometric cycling (QIC), a novel task-specific resistance-training method designed to improve PPO without the use of transitional resistance training, was investigated. Methods: A highly trained sprint track cyclist (10.401 s for 200 m) completed a 5-week training block followed by a second 5-week block that replaced conventional resistance training with the novel QIC training method. The replacement training method required the cyclist to maximally drive the crank of a modified cycle ergometer for 5 seconds as it passed through a ∼100° range (starting at 45° from top dead center) at a constant angular velocity. Each session consisted of 3 sets of 6 repetitions on each leg. The lab PPO was recorded in the saddle and out of the saddle. Results: Conventional training did not alter sprinting ability; however, the intervention improved the out-of-the-saddle PPO by 100 W (from 1751 to 1851 W), while the in-the-saddle PPO increased by 57 W from 1671 to 1728 W. Conclusion: QIC increased PPO in a highly trained, national-level sprint cyclist, which could be translated to improvements in performance on the track. Furthermore, QIC provides a simple, but nonetheless effective, alternative for sprint track cyclists who have compromised function to perform traditional strength training