Dead Lift Research Articles

Predictive and Cross-Validation Analysis of Aerobic and Anaerobic Performance Based on Maximum Strength

To establish the capacity of absolute maximum strength and relative to body mass (BM) in deadlift (DL) and squat (SQ) exercises to estimate the maximum anaerobic running performance (MART) and maximum aerobic power (VPeak), among individuals stratified into high (HS) vs. low strength score (LS). The sum of workloads (DL+SQ) was also analyzed and cross-validation was tested. Thirty-four students performed five visits in the first phase. In the first three visits the following were performed: sample characterization and consistency analysis of the maximum repetition (RM) for DL and SQ. Participants were stratified based on DL and SQ relativized by BM (DL/BM and SQ/BM). In the last two visits, MART and VPeak were tested. Linear regression for HS participants did not predict MART for all strength measures. In contrast, the regressive model was significant for DL (R2 = 0.482; p = 0.002), DL/BM (R2 = 0.764; p < 0.001), SQ (R2 = 0.357; p = 0.011) and SQ/BM (R2 = 0.644; p < 0.001) in LS participants, compared to MART performance. For VPeak, linear regression also did not demonstrate an association for all strength measures in HS participants. However, SQ (R2 = 0.309; p = 0.021), DL/BM (R2 = 0.343; p = 0.013) and SQ/BM (R2 = 0.618; p < 0.001) were able to predict VPeak. The prediction from the sum of the DL+SQ produced an association for MART (R2 = 0.451; p = 0.003) and VPeak (R2 = 0.273; p = 0.031) in LS participants. In the second phase of the study, 17 participants performed cross-validation by testing the prediction equations. The same methodological procedures were performed for this phase, but only LS participants were tested. The Wilcoxon test compared real MART vs. predicted for DL (p = 0.02) and SQ (p = 0.043), showing differences, but not for DL/BM (p = 0.051) and SQ/BM (p = 0.093). The Wilcoxon test also showed differences for real VPeak vs. predicted for DL/BM (p = 0.002), SQ (p = 0.019) and SQ/BM (p = 0.05). The MART predictive equation based on DL+SQ did not show differences (p = 0.148), but the same did not occur for VPeak based on DL+SQ (p = 0.008). Maximum strength did not show predictive capacity in HS participants. However, it was significant for LS participants. DL showed greater predictive prominence for MART. In contrast, for VPeak, SQ/BM satisfactorily explained the variations in running performance (61%). The predictive equations of MART by DL/BM and SQ/BM were shown to be accurate, as well as DL+SQ to predict MART.

Analyzing Targeted Muscle Strength: Impact on Speed, Endurance, and Performance in Female Volleyball

This study examines the influence of muscle strength on performance metrics in volleyball, addressing the need to understand how specific and non-specific strength training impacts athletic capabilities. A cohort of athletes underwent various strength tests, including squats (SQs), bench presses (BPs), and deadlifts (DLs), to assess their force and power during various forms of test. Lactate thresholds (LT1 and LT2) were also measured to evaluate aerobic and anaerobic capacities. The median speed at LT1 was 1.80 m/s, and LT2 was determined at a mean velocity of 2.56 m/s. Notably, a correlation was found between SQ performance and total points scored (p = 0.040, r = 0.285), while upper body strength was strongly correlated with performance metrics, showing significant relationships with points scored (p = 0.0001, r = 0.690) and peak power during BPs (p = 0.0001, r = 0.587). The findings suggest that targeted strength training enhances physical capabilities and improves technical and tactical performance in volleyball, highlighting the critical role of muscle strength in athlete selection and training strategies.

Are caffeine effects equivalent between different modes of administration: the acute effects of 3 mg.kg-1 caffeine on the muscular strength and power of male university Rugby Union players.

There is growing interest in the potential of alternative modes of caffeine administration for enhancing sports performance. Given that alternative modes may evoke improved physical performance via distinct mechanisms, effects may not be comparable and studies directly comparing the erogenicity of alternative modes of caffeine administration are lacking. To address this knowledge gap, the present study evaluated the effect of 3 mg·kg-1 caffeine delivered in anhydrous form via capsule ingestion, chewing gum or mouth rinsing on measures of muscular strength, power, and strength endurance in male Rugby Union players. Twenty-seven participants completed the study (Mean ± SD: Age 20 ± 2 yrs; daily caffeine consumption 188 ± 88 mg). Following assessments and reassessment of chest press (CP), shoulder press (SP), Deadlift (DL), and Squat (SQ) 1-repetition maximum (1RM) and familiarization to the experimental procedures, participants completed six experimental trials where they were administered 3 mg.kg-1 caffeine (Caff) or placebo (Plac) capsule(CAP), chewing gum(GUM) or mouth rinse(RINSE) in a randomized, double-blind and counterbalanced fashion prior to force platform assessment of countermovement jump, drop jump and isometric mid-thigh pull performance. Strength endurance was measured across two sets of CP, SP, DL, and SQ at 70% 1RM until failure. Pre-exercise perceptions of motivation and arousal were also determined. Caffeine increased perceived readiness to invest mental effort (p = .038; ηp2=.156), countermovement jump height (p = .035; ηp2=.160) and SQ repetitions until failure in the first set (p < .001; d = .481), but there was no effect of delivery mode (p > .687; ηp2<.015). Readiness to invest physical effort, felt arousal, drop jump height, countermovement jump, drop jump and isometric mid-thigh pull ground reaction force-time characteristics and repetitions until failure in CP, SP and DL were not affected by caffeine administration or mode of caffeine delivery (p > .0.052; ηp2< .136). 3 mg.kg-1 caffeine administered via capsule, gum or mouth rinse had limited effects on muscular strength, power, and strength endurance. Small effects of caffeine on CMJ height could not be explained by changes in specific ground reaction force-time characteristics and were not transferable to DJ performance, and effects specific to the SQ RTP exercise underpin the complexity in understanding effects of caffeine on muscular function. Novel modes of caffeine administration proposed to evoke benefits via distinct mechanisms did not offer unique effects, and the small number of effects demonstrated may have little translation to a single performance trial when data examining direct comparison of each caffeine vehicle compared against a mode matched placebo is considered.

Analysis of combinatory effects of free weight resistance training and a high-protein diet on body composition and strength capacity in postmenopausal women - A 12-week randomized controlled trial

BackgroundMenopause has a significant impact on the endocrine system of middle-aged women, resulting in a loss of skeletal muscle mass (SMM), changes in fat mass (FM) and a reduction in strength capacity. Resistance training (RT) and a high-protein diet (HPD) are effective methods for maintaining or increasing SMM. This study aims to determine the effects of HPD and RT on body composition, muscle thickness and strength capacity in postmenopausal women. MethodsIn total 55 healthy postmenopausal women (age: 58.2 ± 5.6 years, weight 69.1 ± 9.6 kg, height 166.5 ± 6.5 cm) successfully participated in the study. The women were randomly assigned to either group: training + protein (2.5 g/kg fat-free mass (FFM)) (n = 15; TP); only training (n = 12; T); only protein (2.5 g/kg FFM) (n = 14; CP) or control (n = 14; C). TP and T performed RT for 12 weeks with three training sessions and five exercises each. CP and C were prohibited from training during the period. The main parameters analysed for body composition were FFM, SMM, FM, muscle thickness of the M. rectus femoris, M. biceps femoris, M. triceps brachii and M. biceps brachii muscles. Strength was tested using a dynamometer for grip strength and 1-RM in the squat (BBS) and deadlift (DL). ResultsThe SMM significantly increased by RT (TP: (Δ+1.4 ± 0.9 kg; p < 0.05; d = 0.4; T: Δ+1.2 ± 1.3kg; p < 0.05; d = 0.3) and FM could be reduced only in T: (Δ−2.4 ± 2.9 kg; p < 0.05; d = 0.3). In muscle thickness a significant increase in the M. biceps brachii in both training groups (TP: (Δ+0.4 ± 0.3 cm; p < 0.05; d = 1.6; T: (Δ+0.3 ± 0.3 cm; p < 0.05; d = 0.9) and in M. biceps femoris only in TP (Δ+0.3 ± 0.4 cm; p < 0.05; d = 0.9) were observed. HPD without training does not affect body composition, A significant increase in grip strength (TP: Δ+4.7 ± 2.4 kg; (p < 0.05; d = 1.5; T: (Δ+3.6 ± 3.0 kg; p < 0.05; d = 0.8), in BBS (TP: (Δ+30.0 ± 14.2 kg; p < 0.05; d = 1.5; T: (Δ+34.0 ± 12.0 kg; p < 0.05; d = 2.4) and in DL (TP: (Δ+20.8 ± 10.3 kg; p < 0.05; d = 1.6; T: (Δ+22.1 ± 7.6 kg; p < 0.05; d = 2.0) was observed in both training groups. The CP also recorded a significant increase in the BBS (Δ+7.5 ± 5.4 kg; p < 0.05; d = 0.4) and in DL (Δ+5.5 ± 7.7 kg; p < 0.05; d = 0.5). No significant differences were detected for TP and T for any of the parameters. ConclusionThe results indicate that RT enhances body composition and strength capacity in postmenopausal women and is a preventive strategy against muscle atrophy. Besides HPD without training has a trivial significant effect on BBS and DL. HPD with RT has no clear additive effect on body composition and strength capacity. Further studies are needed to confirm these observations.

Differences in Female Lift Quality During Back Squat, Bench Press, and Deadlift Compared to Standardized Percent of 1RM and Repetitions Allowed

The purpose of the study was to examine the difference between the current norm repetition-intensity recommendations and the performed repetitions of females at concurrent intensities. Females (n = 17) with six-months of consistent resistance training experience completed five testing sessions. Session-one consists of one-repetition maximum (1RM) testing for the squat (SQ), bench press (BP), and deadlift (DL). Sessions 2-5 involved repetition-maximum testing at 65, 75, 85, and 95% 1RM, in the order of SQ, BP, then DL, with 10-15 minutes of rest between exercises. A 3 (exercise) x 4 (percentage-intensity) Mixed Factorial ANOVA determined significant differences in repetitions performed between exercises at each intensity level. A series of one-sample t-tests were performed to indicate female differences between established target repetitions for each exercise across all intensities (65% = 15, 75% = 10, 85% = 6, 95% = 2). Significance level was set at p &lt; .05. There was no significant main effect (p=0.14) between repetitions completed during SQ, BP, or DL at 65% (26.1±6.8, 21.3±6.8, 23.4±6.3, respectively), 75% (18.0±6.2, 14.4±4.2, 15.7±4.7, respectively), 85% (10.3±3.7, 9.0±4.6, 9.6±4.1, respectively), nor 95% 1RM (4.1±2.4, 2.5±2.0, 3.4±2.0, respectively). No significant difference was recognized (p = 0.09) between current norms and female BP repetitions at 95%. Significantly higher repetitions were completed by females at all other percentages during SQ, BP, and DL. These results suggest different resistance training intensity-repetition ratios should be prescribed for females in comparison to current norms; meriting future research aimed at establishing a sex-specific intensity-repetition ratio.

Effects of Resistance Training on Leg-strength and Back-strength in 18-25 Years Women

In the contest of human life there is essentiality of being good. Being good not only means to feel good but also to look good and live well. Now a day’s physical education spreads the wide network in the worldwide. It mainly having two faces they are science and arts. The resistance training is one of the scientific training method in physical education and sports sciences. In this study the researcher has carried on experiments to investigate the effects of resistance training on leg strength and back strength variables before, during and after resistance training. The researcher has taken 50 subjects, and they are divided into two group one is experimental and anther one is control group. The experimental training phase of twelve weeks, the subjects were given resistance training programme trice a week. The exercise are Shoulder Press, Bent-Knee Sit-Ups, Half Squat, Over head press and Dead lift. The collected data’s were analyzed by using SPSS software version 2.0. The result of the study shows that there were significant differences obtained on selected Motor fitness components such as Leg Strength and Back Strength variables of Resistance Training on women in the age group of 18 to 25 years.

The relationship between jumping, acceleration, change of direction, and relative strength for deadlift and back squat1

BACKGROUND: Deadlift (DL) and back squat (BSQ) are considered different exercises because of their kinematic and kinetic characteristics. However, there are similarities, such as joint movement and the maximal muscle strength generated. Although there are differences and similarities, it is unclear which is more related to athletic performance. OBJECTIVE: This study aimed to determine the relationship between DL and jump, acceleration, and change of direction and compare whether DL or BSQ differ in their relationship to jumping, acceleration, and change of direction. METHODS: Eighty male volleyball players (age: 19.6 ± 0.9 years, height: 179.2 ± 6.7 cm, mass: 71.9 ± 9.4 kg) volunteered to participate in this study. Countermovement jump (CMJ), 10-m sprint, and 1–5 repetition maximum (1–5 RM) BSQ were measured on day 1. The T-test and 1–5 RM DL were measured on day 2. RESULTS: DL had a significant and moderate relationship with all parameters of CMJ (r= 0.328, p&lt; 0.01), 10-m sprint (r=-0.471, p&lt; 0.01), and T-test (r=-0.441, p&lt; 0.01). BSQ showed a significant and moderate relationship with the 10-m sprint (r=-0.489, p&lt; 0.01) and T-test (r=-0.356, p&lt; 0.01), but a significant and weak relationship only with CMJ (r= 0.289, p&lt; 0.01). In addition, no significant differences were found in the comparison of correlation coefficients (p&gt; 0.05). CONCLUSIONS: Deadlift may be introduced as an alternative exercise to BSQ when there are limitations in the training environment, such as the lack of a squat rack to safely perform BSQ or home confinement due to external factors like pandemics.

Dead Lifts and Death: Sudden Death due to Hypertrophic Cardiomyopathy in a Body Builder

Background: It is a well established fact that cardiac health and exercise go hand in hand.However, rigorous exercising regimens without proper cardiovascular screening can lead to catastrophic death in unsuspecting and otherwise healthy individuals. Among the underlying undetected cardiovascular conditions that need to be accounted for, especially in young adults, are hypertrophic cardiomyopathies. Case Details: The deceased, a 33-year-old state level bodybuilder, was participating in a body building competition when he suddenly complained of dizziness and collapsed. The deceased appeared to have no signifi cant fi ndings on external examination. Internal examination, however, revealed that the heart was enlarged and weighed 698 g. On microscopic examination, ventricle sections showed enlarged myocytes with disarray and enlarged nuclei. The cause of death was ascertained to be due to complications of hypertrophic cardiomyopathy. Implications For Clinical Practice: Among the feasible options available in low and middle income countries, electrocardiography is an inexpensive method as a screening test, leading the way for using tools such as CMR, serum biomarkers and genetic testing if required. Conclusion: Understanding the relationship between physical exertion and its eff ect on a hypertrophic heart is essential. The case presented brings to light the need for in-depth precompetition screening of athletes. This is especially true since athletes are the one category of individuals where good health is taken for granted.

Correlation relationship between biomechanical links and the result of competitive exercises in powerlifting

Powerlifting is a strength sport, in which competitions are held based on the sum of exercises - squats, bench presses and dead lift. Competition in high performance sports in general and in powerlifting in particular prompts coaches and athletes to search for optimal training programs. Anthropometric indicators of athletes can affect the result in powerlifting in several ways. For example, athletes with higher muscle mass and a lower percentage of body fat have a strength advantage within their category over athletes with a lower level of muscle mass development. Another way is the ratio of the length of the body links. The purpose of the article was to study the influence of the length of body links in qualified and highly qualified powerlifters on performance in competitive exercises. The research was carried out on the basis of the Kharkiv State Academy of Physical Culture. A total of 23 powerlifting athletes took part in the study. The athletes were divided into groups of qualified and highly qualified powerlifters. Statistically significant differences were found in thigh length (t=2.32, p&lt;0.05), leg length (t=2.29, p&lt;0.05), Brugsch index (t=2.40, p&lt; 0.05). A statistically significant inverse relationship was found between standing body length indicators and squats (r=-0.42, p&lt;0.05), deadlift (r=-0.43, p&lt;0.05) and sum (r =-0.42, p&lt;0.05). The length of the thigh and lower leg has an inverse statistically significant relationship with the squat, deadlift, and total sum. The length of the shoulder and forearm are correlated with the bench press (r=0.43, p&lt;0.05) and (r=0.41, p&lt;0.05), respectively. The Brugsch index is statistically significantly correlated with squats (r=0.43, p&lt;0.05), bench press (r=0.54, p&lt;0.01), deadlifts (r=0.44, p&lt;0.05 ), and the amount of sum (r=0.46, p&lt;0.05).

Analysis of Muscle Strength and Electromyographic Activity during Different Deadlift Positions

The aim of the study was to analyze muscle activation in the three positions of the deadlift (DL). Twenty male participants (33.4 ± 3.9 years; 42.2 ± 9.1 months of experience with DL; 91.0 ± 14.8 kg; and 1.78 ± 0.06 m) pulled a bar through isometric actions in three DL positions: lift-off, mid-pull, and lockout. Isometric strength, knee angle, and activation of the rectus femoris (RF), biceps femoris (BF), lateral gastrocnemius (GAL), and erector spinae (ERE) muscles were collected. The analysis of variance showed that the maximum isometric force presented differences between the positions (p = 0.001; η2 = 0.973) considered large with higher values at the mid-pull position. Interactions were found between muscles and position (p = 0.001; η2 = 0.527) considered large. The RF and ERE showed greater activation in the lift-off position, while in the mid-pull position, there was greater activation of the BF and GAL muscles. The DL positions produce different activations in the bi-articular and uni-articular muscles. The lift-off requires more activation from the RF and ERE positions. The mid-pull position, despite generating greater force, presented greater activations in the BF and GAL. The ERE showed higher activations as the external torque was greater.

Dynamics of strength training of qualified wrestlers during weight loss: case study

Purpose: to investigate the dynamics of strength training of qualified wrestlers under the influence of an experimental strength training program during the period of weight loss. Material and Methods. A member of the national freestyle wrestling team. took part in the research. The athlete is 20 years old, and has been practicing wrestling for 9 years. The study was conducted during the preparation for the national championship. A training program was developed for qualified wrestlers, which is advisable to use when preparing for competitions in special conditions of weight loss. The experimental program consisted of a strength training program and a body weight loss program with the use of a specially developed diet and drinking regime, and additional use of ergogenic means was also foreseen. In addition, the experimental training program included special training work. Research methods: analysis of scientific and methodological sources; summarizing the practical experience of specialists; pedagogical observations; pedagogical experiment; pedagogical testing; methods of mathematical statistics. Results. During the study period, the tested athlete, despite a significant decrease in his own weight by 6.5 kg (7.4%), managed to maintain the absolute power index in the bench press (100%), increase the result in the squat with a barbell by 2.8%, by 10% in the dead lift and by 10.5% in the standing long jump. Significant positive changes were observed in the study of relative strength indicators. The subject improved by 8.1% in the bench press, 18.8% in the barbell squat, 11.6% in the dead lift, and 19.3% in the long jump. A significant positive dynamic of the special speed strength indicator is observed when the athlete performs a double leg shot during training bouts (t = 9.4; p ˂ 0.01). The study of general and special speed-power endurance also revealed significant positive changes in the tested athlete. The time for performing a set of Cross Fit exercises decreased by 17.6%. Special Endurance coefficientt improved by 10.7%. Conclusions The results of the study showed that the use of an experimental program for training qualified wrestlers for competitions, in the conditions of reducing body weight, during eight weeks, contributed to a significant positive dynamic of the strength general and special preparedness of the athletes.

Comparison of the effects of deadlift versus back squat on jumping, acceleration, and change of direction1

BACKGROUND: An advantage that deadlift (DL) has over back squat (BSQ) is that the latter requires additional equipment (i.e., squat rack). Accordingly, if DL can lead to positive effects on jumping, acceleration, and change of direction, DL could present as a more practical training exercise than that of BSQ. OBJECTIVE: This study aimed to compare the effects of DL and BSQ on jumping, acceleration, and change of direction. METHODS: Twenty-three men (12 in the DL group [age: 20.3 ± 1.4 years old, height: 169.6 ± 6.7 cm, body weight: 65.7 ± 11.2 kg] and 11 in the BSQ group [age: 20.2 ± 1.9 years old, height: 171.5 ± 4.8 cm, body weight: 70.1 ± 6.8 kg]) participated in this study. The participants performed five repetitions maximum (RM) of DL and BSQ, and the isokinetic strength of hip joint extension, muscle thickness of the gluteus maximus and hamstrings, countermovement jump (CMJ) height, 10 m sprint time, and T-test results were measured. The 1RM was estimated using the 5RM and normalized to body weight (BW). Both groups performed supervised DL and BSQ training for eight sessions. RESULTS: There were significant improvements on 1RM DL/BW (p&lt; 0.01), 1RM BSQ/BW (p&lt; 0.01), and 10 m sprint (p&lt; 0.01) in the two groups. The effect sizes (d) of the DL and BSQ groups were 2.01 and 1.04 for 1RM DL/BW, 1.08 and 2.08 for 1RM BSQ/BW, 0.35 and 0.11 for CMJ height, and -0.94 and -0.54 for 10 m sprint, respectively. CONCLUSIONS: DL training might improve jumping and acceleration compared to those of BSQ training.

Analysis of Competition Performance Leading to Success at the International Powerlifting Federation World Championships Between 2013 and 2019.

van den Hoek, D, Garrett, J, Travis, SK, Oxnard, K, Howells, R, Owen, P, and Latella, C. Analysis of competition performance leading to success at the International Powerlifting Federation World Championships between 2013 and 2019. J Strength Cond Res 37(10): e555-e562, 2023-Despite being a global sport, there is a paucity of research investigating competition-related factors contributing to World Championship powerlifting success. Therefore, the aim of this study was to determine competition strategies that underpin gold medalists' (GMs) and silver or bronze medalists' (SBMs) performances. Data collected from open-age International Powerlifting Federation (IPF) World Championship events 2013-2019 were analyzed (1,312 competitors [males n = 734, females n = 578]). Attempt weight and success for the squat (SQ), bench press (BP), and deadlift (DL); 'total' competition scores; category (age, weight class, and sex); and placing were categorized into 3 groups: GMs, SBMs, and nonwinners (fourth place or lower). One-way analysis of variances determined between group differences. Odds ratios (ORs) for the likelihood of winning and placing (i.e., GMs or SBMs) were also calculated. The odds of winning a competition were increased 5.9 times for men and by 1.5 times for women, when successfully completing 8 or 9 of 9 lift attempts. These findings provide comprehensive insight into intracompetition-related factors that contribute to World Championship powerlifting success to directly inform coach and athlete strategies. This information may also hold relevance for competitive state or national competitions and extend to other similarly structured strength-based sports.

The Relationship Between Partial and Full Range of Motion Deadlift 1-Repetition Maximum: A Technical Note.

Gillingham, B, Bishop, A, Higa, GK, Adams, KJ, and DeBeliso, M. The relationship between partial and full range of motion deadlift 1-repetition maximum: a technical note. J Strength Cond Res 37(4): 909-914, 2023-The full range of motion (FROM) or partial range of motion (PROM) deadlift (DL) are often included in resistance training (RT) programs and are performed by strength athletes in competition. This study examined the relationship between the FROM and PROM 1-repetition maximum (1RM) DL and if the PROM 1RM DL can be estimated by the FROM 1RM DL. Eighteen National Collegiate Athletic Association wrestlers (20.8 ± 1.2 years, 176.0 ± 5.2 cm, 78.9 ± 10.6 kg) performed a warm-up followed by the assessment of the FROM and PROM 1RM DLs. The FROM DLs were executed with a starting position of the bar resting on the lifting platform. Partial range of motion DLs were executed in a power rack with the bar starting position at ≈2.54 cm above the patella. Regression analysis was employed to estimate PROM 1RM DL based on FROM 1RM DL, body height, and mass. A Pearson's correlation coefficient ( r ) was used to compare the PROM 1RM DL with FROM 1RM DL. A dependent t test was used to compare the PROM 1RM DL and FROM 1RM DL scores (α < 0.05). The PROM 1RM DL scores (226.0 ± 40.6 kg) were significantly greater than the FROM 1RM DL scores (191.7 ± 37.2 kg) ( p < 0.05: effect size = 0.92). The PCC between the PROM and FROM 1RM DL was r = 0.85 ( p < 0.05). The regression coefficient for the FROM 1RM DL was significant ( p < 0.05; R = 0.85, R2 = 0.73). The regression coefficients for body mass and height were not significant ( p > 0.05). The PROM and FROM DL may be interchangeable modalities within an RT program, and the PROM 1RM DL can be accurately predicted by the FROM 1RM DL.

Effects of 6-Week Betaine Supplementation on Muscular Performance in Male Collegiate Athletes.

Simple SummaryBetaine supplementation has ergogenic potential for exercise performance, but the effect of betaine supplementation in combination with training for 6 weeks is still unclear. The present study aimed to investigate the effects of betaine supplementation on muscular power and maximal strength in collegiate male athletes. The participants in the study received either 5 g/day of betaine or placebo for 6 weeks, during which they maintained their regular exercise training. The overhead medicine-ball throw, countermovement jump, and one repetition-maximum of a bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. We found that receiving 5 g of betaine supplementation daily during the 6-week preparatory period had extra benefits on the power of the upper body and maximal strength on the half squat and overhead press. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.The purpose of this study was to investigate the effects of 6-week betaine supplementation during a preparatory period of collegiate athletes on muscular power and strength. Sixteen male collegiate athletes received 5 g/day of betaine (betaine group, n = 9) or carboxymethyl cellulose (placebo group, n = 7) for 6 weeks. All participants engaged in their regular training during the experimental period. The overhead medicine-ball throw (OMBT), countermovement jump, and maximal strength (one repetition maximum, 1-RM) on the bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. After supplementation, there were no significant differences between betaine and placebo groups on any variables. Compared to presupplementation, the performance of OMBT and 1-RM of overhead press and half squat in the betaine group had significantly improved (p < 0.05). By contrast, no significant differences were observed in the placebo group before and after supplementation. Blood analysis revealed no negative effect on blood lipid profiles. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.

Bayesian analysis of changes in standing horizontal and vertical jump after different modes of resistance training

ABSTRACT Training interventions often have small effects and are tested in small samples. We used a Bayesian approach to examine the change in jump distance after different resistance training programmes. Thirty-three 18- to 45-year-old males completed one of three lower limb resistance training programmes: deadlift (DL), hip thrust (HT) or back squat (BS). Horizontal and vertical jump performance was assessed over the training intervention. Examination of Bayesian posterior distributions for jump distance estimated that the probability of a change above a horizontal jump smallest worthwhile change (SWC) of 4.7 cm for the DL group was ~12%. For the HT and BS groups, the probability of a change above the SWC was ~87%. The probability of a change above a vertical jump SWC of 1.3 cm for the DL group was ~31%. For the HT and BS groups, the probability of a change above the vertical jump SWC was ~62% and ~67%, respectively. Our study illustrates that a Bayesian approach provides a rich inferential interpretation for small sample training studies with small effects. The extra information from such a Bayesian approach is useful to practitioners in Sport and Exercise Science where small effects are expected and sample size is often constrained.

Resistance Training Enhances Muscle Function and Hemorheological Properties in Middle‐aged Obese Women

PurposeThe present study investigated the effects of resistance training for 12‐week on body composition, blood pressure, blood lipid level, cross sectional area (CSA) of muscles, isokinetic muscle function, and hemorheological properties in middle‐aged obese women.MethodsThirty obese women (50.79 ± 5.80 years), with no history of any injuries to the musculoskeletal system and no participating any regular exercise program, were included in the present study. All participants were randomly assigned to a control group (CON, n = 15) or an experimental group (EXP, n = 15); but two participants in the CON voluntarily withdrew because of personal reasons, and thirteen participants in the CON finally participated. The EXP underwent resistance training program composed of warm‐up, main resistance exercise (bench press, preacher bench biceps curl, barbell rowing, dumbbell shoulder press, dead lift, barbell squat, seated leg extension, and lying leg curl), and cool‐down. Main resistance exercise was consisted of three sets of 8–10 repetitions (reps) performed with 80% of 1‐RM. The training frequency was 80 min, 3 days per week for 12 weeks. The CON maintained their daily lifestyle without training. All participants underwent body composition (weight, body mass index, lean body mass, fat mass, and %body fat), blood pressure (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure), blood lipid level (triglyceride, total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol), cross sectional area (CSA) of muscles (quadriceps CSA, hamstring CSA, and total thigh muscle CSA), isokinetic muscle function (peak torque, relative peak torque, mean power, and total work in quadriceps femoris and hamstrings), and hemorheological properties (erythrocyte deformability and erythrocyte aggregation) were measured before and after 12‐week of training.ResultsThe EXP showed a significant decrease in fat mass (p = .018) via 12‐week of resistance training. Also, the EXP yielded more significant improved muscle function including peak torque (p &lt; .001), relative peak torque (p &lt; .001), and total work (p = .001) in quadriceps femoris and total work (p = .018) in hamstrings. Regarding hemorheological properties, the EXP showed a significant increase in erythrocyte deformability (p = .001) via 12‐week of resistance training. However, there was no significant change in blood pressure and muscle CSA parameters via 12‐weeks of resistance training.ConclusionThe present study verified our resistance training program shows greater muscle strength and endurance, decreasing fat mass, and improving hemorheological properties such as erythrocyte deformability.

Muscle forces and fascicle behavior during three hamstring exercises.

Knowledge about muscular forces and fascicle behavior during hamstring exercises can optimize exercise prescription, but information on these outcomes across different exercises is lacking. We aimed to characterize and compare lower‐limb muscle forces and biceps femoris long head muscle fascicle behavior between three hamstring exercises: the Nordic hamstring curl (NHC), single‐leg Roman chair (RCH), and single‐leg deadlift (DL). Ten male participants performed the exercises while full‐body kinematics, ground reaction forces, surface muscle activation, and biceps femoris long head fascicle behavior were measured. Mean fascicle length was highest in the DL, followed by the RCH and NHC. Fascicle lengthening was higher in the NHC compared with the RCH and DL, with no difference between the RCH and DL. Biceps femoris short and long head, semitendinosus, and semimembranosus peak forces were generally higher in the NHC compared with the RCH and DL, while mean forces during the eccentric phase were generally not different between the NHC and RCH. Peak forces in the NHC coincided with low biceps femoris long head and semimembranosus muscle activation. The NHC generally has the highest peak hamstring muscle forces and results in more fascicle lengthening when compared to the DL and RCH. The NHC may therefore be most effective to promote increases in fascicle length. While the NHC may be effective to promote biceps femoris short head and semitendinosus strength adaptations, the RCH and DL may be more effective to promote strength increases in the biceps femoris long head and semimembranosus.

The relationship between powerlifting performance and hand grip strength among female athletes

With the rising competitiveness in the sport of powerlifting, coaches and athletes are continually looking for better ways to measure progress to predict and improve performance. Many studies have evaluated the link between hand grip strength (HGS) and performance in other sports, and HGS has been a predictor of total body strength. The current study examined the relationship between HGS and powerlifting performance among experienced female powerlifters. HGS was compared to the 1RM of the squat (SQ), bench press (BP), deadlift (DL) and aggregate total. It was hypothesized that there would be a positive meaningful relationship between HGS and powerlifting performance. Thirty-one (n=31) female powerlifting participants (age 29±6.3 years, body mass 82.8±27.8 kg) with at least 3 months of powerlifting training experience were assessed for HGS and powerlifting performance measures. Hand grip strength was measured with a Jamar hydraulic hand dynamometer prior to a sanctioned powerlifting meet. Three trials of HGS were completed by the participants where each trial was separated by 1-minute rest period. The average of the two highest HGS scores were recorded for analysis. The powerlifting performance measures were assessed at a sanctioned powerlifting meet comprised of 1 repetition maximums (1RM) in three event lifts, the back squat (BS), bench press (BP) and deadlift (DL). The event 1RMs, aggregate total (AT), and HGS scores were then normalized to body mass (BM). The normalized event 1RMs and AT were then compared to the normalized HGS scores with Pearson correlation coefficients (r). The BS, DL and AT scores demonstrated moderately significant relationships (r=0.46, r=0.51, r=0.48) respectively with HGS (p

Acute and delayed effects of strength training in ball velocity and accuracy in young competition tennis players.

This study aimed to investigate the acute and delayed effects of medicine ball throws and resistance training in ball velocity and accuracy of serve, forehand and backhand in young competition tennis players. A crossover-randomized design was used with 10 competition tennis players (6 girls and 4 boys between 14 and 18 years old). The subjects performed 6 stroke test sessions, 3 for each strength protocol. The velocity and accuracy of strokes were measured before (basal situation), 3 minutes, 24 and 48 hours after the protocol. Medicine ball throws protocol was performed by accomplishing 3 sets of 6 repetitions using a 2 kg ball, throwing it at maximal speed. Resistance training protocol was performed by accomplishing 3 sets of 6 repetitions at 75% one-repetition maximum, lifting the load at maximal speed of bench press, dead lift, one hand row and half squat. There were no significant (p > 0.05) differences in all strokes, regarding ball velocity and accuracy after each method and each recovery time, compared to the basal situation. These results suggest that medicine ball throws and resistance training methods have no acute and delayed detrimental effects on stroke velocity and accuracy in young competition tennis players.