Papers by Danny Lum Hon Kuan Lum
Journal of Strength and Conditioning Research, Feb 1, 2019
The purposed of this study was to compare the effects of postactivation potentiation (PAP) on Spe... more The purposed of this study was to compare the effects of postactivation potentiation (PAP) on Special Judo Fitness Test (SJFT) performance using explosive exercises that activates upper and lower limbs muscles. Eleven male judo athletes (mean ± SD, age, 16-29 years; height, 170 ± 7 cm; body mass, 73 ± 16 kg) attended four separate sessions. The first session was used to familiarise the subjects to the experimental procedure, the SJFT, the high pull test (HPT) and the two explosive exercises including resistance band pull and standing broad jump. Subsequently, subjects were randomly assigned in a counterbalanced manner to either perform the upper and lower body PAP (ULB), lower body PAP (LB) or usual competition (CON) warm up routine prior to performing the HPT and SJFT. The following variables were quantified: throws performed during series A, B, and C; total number of throws; heart rate immediately and 1 minute after the test; test index; peak power; and RPE after warm up. During series 1, number of throws performed in LB and ULB were significantly greater than CON (p < 0.05). Only ULB resulted in significantly greater number of total throws (p < 0.01) and higher peak power (p < 0.01) than CON. The RPE for both LB and ULB were significantly lower than CON (p < 0.01). Peak power was moderately correlated to total number of throws performed (r=0.4, p < 0.05). This study suggest that performing ULB before SJFT can result in improved performance and peak power.
International Journal of Sports Physiology and Performance, Nov 1, 2019
To evaluate the effect of strength training on Olympic time-based sports (OTBS) time-trial perfor... more To evaluate the effect of strength training on Olympic time-based sports (OTBS) time-trial performance and provide an estimate of the impact of type of strength training, age, training status, and training duration on OTBS time-trial performance. Methods: A search on 3 electronic databases was conducted. The analysis comprised 32 effects in 28 studies. Posttest time-trial performance of intervention and control group from each study was used to estimate the standardized magnitude of impact of strength training on OTBS time-trial performance. Results: Strength training had a moderate positive effect on OTBS time-trial performance (effect size = 0.59, P c. 01). Subgroup meta-analysis showed that heavy weight training (effect size = 0.30, P = .01) produced a significant effect, whereas other modes did not induce significant effects. Training status as factorial covariate was significant for well-trained athletes (effect size = 0.62, P = .04), but not for other training levels. Meta-regression analysis yielded nonsignificant relationship with age of the participants recruited (/) =-0.04; 95% confidence interval,-0.08 to 0.004; P = .07) and training duration (/? =-0.05; 95% confidence interval,-0.11 to 0.02; P-.15) as continuous covariates. Conclusion: Heavy weight training is an effective method for improving OTBS time-trial performance. Strength training has greatest impact on well-trained athletes regardless of age and training duration.
International Journal of Sports Medicine, Apr 3, 2019
This review used a narrative summary of findings from studies that focused on isometric strength ... more This review used a narrative summary of findings from studies that focused on isometric strength training (IST), covering the training considerations that affect strength adaptations and its effects on sports related dynamic performances. IST has been shown to induce less fatigue and resulted in superior joint angle specific strength than dynamic strength training, and benefited sports related dynamic performances such as running, jumping and cycling. IST may be included into athletes’ training regime to avoid getting overly fatigue while still acquiring positive neuromuscular adaptations; to improve the strength at a biomechanically disadvantaged joint position of a specific movement; to improve sports specific movements that require mainly isometric contraction; and when athletes have limited mobility due to injuries. To increase muscle hypertrophy, IST should be performed at 70–75% of maximum voluntary contraction (MVC) with sustained contraction of 3–30 s per repetition, and total contraction duration of&gt;80–150 s per session for&gt;36 sessions. To increase maximum strength, IST should be performed at 80–100% MVC with sustained contraction of 1–5 s, and total contraction time of 30–90 s per session, while adopting multiple joint angles or targeted joint angle. Performing IST in a ballistic manner can maximize the improvement of rate of force development.
Sports, May 15, 2020
The purpose of this article was to review the data on the relationship between multi-joint isomet... more The purpose of this article was to review the data on the relationship between multi-joint isometric strength test (IsoTest) force-time characteristics (peak force, rate of force development and impulse) and dynamic performance that is available in the current literature. Four electronic databases were searched using search terms related to IsoTest. Studies were considered eligible if they were original research studies that investigated the relationships between multi-joint IsoTest and performance of dynamic movements; published in peer-reviewed journals; had participants who were athletes or active individuals who participate in recreational sports or resistance training, with no restriction on sex; and had full text available. A total of 47 studies were selected. These studies showed significant small to large correlations between isometric bench press (IBP) force-time variables and upper body dynamic performances (r 2 = 0.221 to 0.608, p < 0.05) and significant small to very large correlation between isometric squat (ISqT) (r 2 = 0.085 to 0.746, p < 0.05) and isometric mid-thigh pull (IMTP) (r 2 = 0.120 to 0.941, p < 0.05) force-time variables with lower body dynamic performances. IsoTest force-time characteristics were shown to have small to very large correlations with dynamic performances of the upper and lower limbs as well as performance of sporting movements (r 2 = 0.118 to 0.700, p < 0.05). These data suggest that IsoTest force-time characteristics provide insights into the force production capability of athletes which give insight into dynamic performance capabilities.
Journal of Strength and Conditioning Research, May 9, 2022
Lum, D, Joseph, R, Ong, KY, Tang, JM, and Suchomel, TJ. Comparing the effects of long-term vs. pe... more Lum, D, Joseph, R, Ong, KY, Tang, JM, and Suchomel, TJ. Comparing the effects of long-term vs. periodic inclusion of isometric strength training on strength and dynamic performances. J Strength Cond Res 37(2): 305–314, 2023—This study compared the effects of including isometric strength training (IST) for consecutive 24 weeks (CIST) against a periodic inclusion (PIST) of this mode of training on strength and dynamic performances. Twenty-four floorball athletes (age: 23 ± 2.7 years, stature: 1.74 ± 2.08 m, and body mass: 72.7 ± 14.4 kg) were randomly assigned to the control (CON), CIST, or PIST group. Athletes completed 20-m sprint, countermovement jump (CMJ), and isometric midthigh pull (IMTP) during pre-test and were tested on weeks 6, 12, 18, and 24. All groups performed a similar strength training program twice per week. However, 2 sets of squats were replaced with isometric squat in CIST for all 24 weeks but only on weeks 1–6 and 13–18 for PIST. A significant main effect for time was observed for 5-, 10-, and 20-m sprint time, CMJ height, peak force, peak power, time to take-off, modified reactive strength index, IMTP peak force, relative peak force, and force at 200 milliseconds (p = &lt;0.001–0.037). Isometric strength training for 24 consecutive weeks resulted in greater improvement in 5-m sprint time than CON at week 24 (p = 0.024, g = 1.17). Both CIST and PIST resulted in greater improvements in 10-m sprint time than CON at various time points (p = 0.007–0.038 and 0.038, g = 1.07–1.44 and 1.18, respectively). Isometric strength training for 24 consecutive weeks and PIST resulted in greater improvements in 20-m sprint time than CON at week 6 (p = 0.007 and 0.025, g = 1.65 and 1.40, respectively). The results showed that the inclusion of IST resulted in greater improvements in sprint performance than CON but no significant difference in all measured variables with PIST.
International Journal of Sports Physiology and Performance, Jul 1, 2022
Isometric strength training has been reported to benefit various sport-related dynamic performanc... more Isometric strength training has been reported to benefit various sport-related dynamic performances. However, it is still unknown whether performing isometric strength training at single or multiple joint angles would elicit greater benefit. Purpose: To compare the effects of isometric bench press performed at single (SIBP) and multiple (MIBP) joint angles on dynamic strength and overhead throwing performance. Methods: Sixteen male softball and baseball athletes performed overhead throwing, 1-repetition-maximum (1RM) bench press, and ballistic push-up during pretest and posttest. They were then randomly assigned to either SIBP or MIBP to undergo 12 strength training sessions. During the training, isometric bench press was performed at only 90° elbow angle for SIBP but at 60°, 90°, and 120° elbow angles for MIBP. Results: A significant main time effect was observed for bench press 1RM (P = .003) and relative 1RM (P &lt; .001). Similarly, a significant main time effect was observed for ballistic push-up peak power only (P = .037). There was no significant change in overhead throwing velocity in either group. There was also no significant difference in change in all measures between groups. However, a moderate effect in favor of MIBP was observed for change in ballistic push-up peak power (P = .180, g = 0.67). Conclusions: Based on the current findings, the inclusion of both SIBP and MIBP were equally beneficial to maximal strength development. However, performing MIBP had a greater effect on power development.
El uso de diversos modos de ejercicio para inducir la potenciacion posactivacion (PAP) ha sido es... more El uso de diversos modos de ejercicio para inducir la potenciacion posactivacion (PAP) ha sido estudiado en la literatura actual. Sin embargo, ningun articulo de revision ha discutido las ventajas y las desventajas de estos multiples modos de ejercicios para inducir la PAP. Esta revision presenta un breve debate sobre los resultados disponibles acerca de los efectos de diferentes ejercicios para inducir PAP. Los entrenadores y los atletas deben tener en cuenta la informacion disponible porque la magnitud del efecto de la PAP puede variar segun el modo de ejercicio realizado.
Sports, Jan 21, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Sports, 2021
Performing isometric strength training (IST) can enhance various sports performance. This study c... more Performing isometric strength training (IST) can enhance various sports performance. This study compared the effects of including IST on sprint kayaking performance as compared to traditional strength training. Twenty sprint kayaking athletes (age 22 ± 4 year, stature 1.71 ± 0.09 m, body mass 72.0 ± 11.4 kg) performed a 200-m kayak ergometer time trial (200mTT), isometric squat (IsoSqT), isometric bench press (IsoPress) and isometric prone bench pull (IsoPull) during the pre- and post-tests. Athletes were randomly assigned to either traditional strength training (TRAD) or IST group. Both groups performed a similar strength training program twice a week for six weeks. However, half the volume for squat, bench press and prone bench pull were replaced by IsoSqT, IsoPress and IsoPull, respectively, for the IST group. IsoSqT was performed at 90° knee angle, while IsoPress and IsoPull were performed at 90° and 120° elbow angles, respectively. Each isometric contraction was performed with ...
International Journal of Sports Physiology and Performance, 2022
Isometric strength training has been reported to benefit various sport-related dynamic performanc... more Isometric strength training has been reported to benefit various sport-related dynamic performances. However, it is still unknown whether performing isometric strength training at single or multiple joint angles would elicit greater benefit. Purpose: To compare the effects of isometric bench press performed at single (SIBP) and multiple (MIBP) joint angles on dynamic strength and overhead throwing performance. Methods: Sixteen male softball and baseball athletes performed overhead throwing, 1-repetition-maximum (1RM) bench press, and ballistic push-up during pretest and posttest. They were then randomly assigned to either SIBP or MIBP to undergo 12 strength training sessions. During the training, isometric bench press was performed at only 90° elbow angle for SIBP but at 60°, 90°, and 120° elbow angles for MIBP. Results: A significant main time effect was observed for bench press 1RM (P = .003) and relative 1RM (P < .001). Similarly, a significant main time effect was observed fo...
Biology of Sport, 2022
Plyometric vs isometric strength training INTRODUCTION Various forms of strength training includi... more Plyometric vs isometric strength training INTRODUCTION Various forms of strength training including free weights, plyometrics (PLYO) and isometric strength training (ISO) have been used with the purpose of increasing force production to enhance athletic performances [1, 2]. The force producing capacity of a muscle is influenced by the muscle action (i.e. concentric, eccentric, isometric), due to differences in neural activation [3, 4]. Furthermore, each mode of strength training has been shown to result in different magnitude of adaptation to muscle hypertrophy, strength and power [1, 2]. Although eccentric strength training has been reported to induce enhanced hypertrophic response as compared to other modes of strength training [2], comparison of strength increases remains controversial as magnitude of adaptation resulting from each different mode of strength training is dependent on the method of assessment (i.e. eccentric training will induce greater increment in eccentric strength; concentric training will induce greater increment in concentric strength; and ISO
Journal of Functional Morphology and Kinesiology, 2021
In badminton, power production can be enhanced through the fundamental practice of a dynamic warm... more In badminton, power production can be enhanced through the fundamental practice of a dynamic warm-up with resistance conditioning activity to induce a post-activation performance enhancement (PAPE) effect. The use of heavy resistance exercise in the form of heavy weights to induce PAPE during competition is not logistically practical in the badminton arena. Thus, there is a need to investigate the use of easily available alternative preconditioning stimuli to induce a similar potentiating effect in badminton-specific performance. This study adopted a repeated-measures design of three warm-up conditions: control (CON), weighted wearable resistance (WWR), and resistance band variable resistance (BVR). Fourteen badminton players from the national training squad (11 males, 3 females, age 18 ± 1 y) completed the experimental sessions in random order. Change of direction speed (CODS) and smash velocity (SV) tests were performed at five timepoints—baseline test after the warm-up and at the...
Scientific Reports, 2020
The aim of this study was to analyse the front-crawl arm-pull kinetics and kinematics, comparing ... more The aim of this study was to analyse the front-crawl arm-pull kinetics and kinematics, comparing it before and after post-activation potentiation (PAP), and the associations between variables describing of the arm-pull kinetics. Twelve male competitive swimmers were randomly assigned to perform two different warm-ups in a crossover manner: (i) non-PAP (control condition); and (ii) PAP (experimental condition). PAP consisted of 2 × 5 arm-pulls with resistance bands by both upper-limbs. Eight minutes later, participants underwent a 25 m all-out trial in front-crawl arm-pull. Kinetics (i.e., peak thrust, mean thrust and thrust-time integral) and kinematics (i.e., speed and speed fluctuation) were collected by an in-house customised system composed of differential pressure sensors, speedo-meter and underwater camera. There was a significant and large improvement of the arm-pull kinetics after completing the warm-up with PAP sets (0.010 < P < 0.054, 0.50 < d < 0.74). There we...
Journal of Science in Sport and Exercise, 2021
Purpose Isometric strength training (IST) with rapid non-sustained contraction (RIST) is effectiv... more Purpose Isometric strength training (IST) with rapid non-sustained contraction (RIST) is effective in improving the ability to generate force rapidly. However, the neuromuscular adaptation of IST with sustained contraction (SIST) and RIST is not known. Therefore, the aim of the study was to compare the neuromuscular adaptations of RIST with SIST. Methods Thirty-three national floorball players (23.9 ± 3.1 years old; 1.69 ± 0.08 m; 64.6 ± 11.1 kg) were recruited for this study. Pre-and post-test included countermovement jump (CMJ), 30-m sprint (TT30), isometric squat at 90° (ISqT90) and 120° (ISqT120) knee angles. They were randomly assigned to either control (Con) (n = 9), RIST (n = 12) or SIST (n = 12) group and performed 12 sessions of intervention training. All groups performed the same sets of exercises, but RIST and SIST had to perform ISqT with and without sustained contraction, respectively. Results Time × group effect for CMJ height (P = 0.01, ƞ p 2 = 0.25), peak force (PF) (P = 0.03, ƞ p 2 = 0.22) and rate of force development (RFD) (P = 0.02, ƞ p 2 = 0.22) obtained from ISqT120 were noted. A main effect for time was observed in CMJ height, PF obtained from ISqT90 and ISqT120, and RFD obtained from ISqT90 (P < 0.01, 0.27 < ƞ p 2 < 0.57). There was greater improvement in TT30 (P = 0.043, d = 3.00), ISqT90 PF (P = 0.034, d = 3.12), ISqT120 PF (P = 0.003, d = 4.54) and ISqT120 RFD (P = 0.033, d = 1.36) in the SIST than the Con group. Conclusion SIST was more effective in improving strength and dynamic performance as compared to RIST, making it a viable training method to enhance dynamic performances.
Frontiers in Psychology, 2021
The aim of this meta-analysis was to evaluate the effects of complex training (CT) on sprint, jum... more The aim of this meta-analysis was to evaluate the effects of complex training (CT) on sprint, jump, and change of direction (COD) ability among soccer players. After an electronic search, 10 peer-reviewed articles were considered in the meta-analysis. The athletes included in this meta-analysis were amateur to professional level male soccer players (age range, 14–23 years). These studies incorporated CT in soccer players who were compared to a control group. Significant moderate to large improvements were observed in the CT group [sprint: standard mean difference (SMD) = 0.92–1.91; jump: SMD = 0.96–1.58; COD: SMD = 0.97–1.49] when compared to control groups. Subgroup analysis were also conducted based on age, duration, and competitive level. The beneficial effects of CT were greater in players <18 vs. ≥18 years (linear sprinting; SMD = 2.01 vs. −0.13), after ≥8 vs. <8 weeks (jumping and COD; SMD = 1.55–2.01 vs. 0.31–0.64, respectively) and among professional vs. amateur player...
Journal of Trainology, 2020
The relationship between force-time characteristics obtained from isometric mid-thigh pull (IMTP)... more The relationship between force-time characteristics obtained from isometric mid-thigh pull (IMTP) and endurance running performance has not been studied. The purpose of this study was to investigate the relationships between force-time characteristics obtained from IMTP with indicators of endurance running performance. Design and Methods: Participants attended a familiarisation session to be familiarised with all testing protocols. Subsequently, they completed the IMTP and a 2.4-km run time trial (2.4-kmTT) on the first testing session. Post 48-72 h of the first session, they then performed a running economy (RE) test at 12 km.h-1 and graded exercise test on the second testing session. Results: Significant inverse correlations between all IMTP measures and 2.4kmTT was observed (r =-0.53 to-0.78, p < 0.01). Similarly, all IMTP measures were significantly correlated to maximal aerobic speed (r = 0.38 to 0.66, p < 0.05) except Force at 150 ms. There were significant correlations between IMTP peak force, net peak force and rate of force development (0-150 ms) with lower limb stiffness (r = 0.41 to 0.49, p < 0.05). Force at 100 ms and all rate of force development measures were significantly correlated to RE (r =-0.44 to-0.68, p < 0.05). Conclusion: Findings showed that measures obtained from IMTP are good indicators of endurance running performance and can provide insights into the force generating capability required by endurance runners. In addition, the significant correlations between strength measures and running performance suggest that muscular strength may be an important determinant of running performance.
Journal of Science in Sport and Exercise, 2020
The aim of the study was to establish the optimum variable resistance (VR) intensity for loaded c... more The aim of the study was to establish the optimum variable resistance (VR) intensity for loaded countermovement jump (LCMJ) to induce post-activation potentiation (PAP). Methods Eleven male athletes (age 23 ± 2.3 years, height 1.77 ± 0.05 m, body mass 73.7 ± 9.0 kg) attended one familiarization and four testing sessions. Subjects performed their own pre-competition warm up before performing two countermovement jumps (CMJ) for baseline measure. Subsequently, they performed 2 × 3 unloaded (UCMJ) or loaded CMJ (LCMJ) with one of the three VR intensities, Orange (6.7 ± 0.6 kg), Red (14.0 ± 0.9 kg) and Blue (24.0 ± 1.4 kg), in random order, before performing two more CMJ for post-test measure. Each testing session was separated by at least 48 h. Results There was significant increase in jump height in all conditions (P < 0.05), but no significant difference in change in jump height between conditions (P > 0.05). There were small to moderate effect when comparing Orange and the other conditions. Peak force and velocity increased in Red (P < 0.05) and Orange (P < 0.05), respectively. Change in jump height was significantly correlated to change in peak velocity (r = 0.46, P = 0.002) and peak power (r = 0.46, P = 0.002). Conclusion The findings of the study showed that UCMJ and LCMJ were effective in improving jump height acutely, and an intensity level of about 10% body weight contributed by VR seems to be the optimum resistance level.
Strength & Conditioning Journal, 2019
The use of various modes of exercise to induce postactivation potentiation (PAP) has been studied... more The use of various modes of exercise to induce postactivation potentiation (PAP) has been studied in the current literature. However, discussion on the advantages and disadvantages of these multiple modes of exercises in inducing PAP within one review study has not been conducted. A brief discussion on the available findings on the effects of different exercises in inducing PAP is presented in this review. Coaches and athletes should take the available information into consideration because the magnitude of PAP effect may vary depending on the mode of exercise performed.
International Journal of Sports Physiology and Performance, 2019
Purpose: To evaluate the effect of strength training on Olympic time-based sports (OTBS) time-tri... more Purpose: To evaluate the effect of strength training on Olympic time-based sports (OTBS) time-trial performance and provide an estimate of the impact of type of strength training, age, training status, and training duration on OTBS time-trial performance. Methods: A search on 3 electronic databases was conducted. The analysis comprised 32 effects in 28 studies. Posttest time-trial performance of intervention and control group from each study was used to estimate the standardized magnitude of impact of strength training on OTBS time-trial performance. Results: Strength training had a moderate positive effect on OTBS time-trial performance (effect size = 0.59, P < .01). Subgroup meta-analysis showed that heavy weight training (effect size = 0.30, P = .01) produced a significant effect, whereas other modes did not induce significant effects. Training status as factorial covariate was significant for well-trained athletes (effect size = 0.62, P = .04), but not for other training leve...
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Papers by Danny Lum Hon Kuan Lum