PURPOSE The purpose of this study is to analyze SNPs related to performance (maximal strength vs. cardiovascular endurance) of world-class Korean elite athletes using the Genome-Wide Human SNP Array ...6.0 and to determine genotypes related to maximal strength and cardiovascular endurance performance that are unique to “ Koreans”. METHODS Using the Genome-Wide Human SNP Array 6.0, we analyzed SNPs obtained from 54 world-class Korean elite athletes (Olympic participants/World Championship medalists). The group was divided into the 16 maximal strength group (12 males and 4 females weightlifters who had won medals at the Olympic and World Championships), 12 cardiovascular endurance group (12 males marathon runners who had run within 2 hours and 12 minutes in international competitions), and 26 individuals from the general population (25 males and 1 female). All the obtained SNPs were subjected to quality control (QC), and a total of 867,982 SNPs were analyzed between the marathon runners and general population subjects (641,040 SNPs) and between weightlifters and general population subjects (634,418 SNPs). RESULTS The number of SNPs with more than two SNPs within 100 kb, which satisfied the threshold of sample QC and significance level of p<.0001, was 60 in marathoners and 18 in weightlifters compared to the general population subjects. When the genomic features of SNPs of each performance trait were analyzed, the 60 SNPs for cardiovascular endurance with two or more SNPs within 100 kb that met the p<.0001 threshold for significance were distributed across 15 regions, and the 18 SNPs for maximal strength were distributed across 7 regions. CONCLUSIONS In conclusion, SNPs related to cardiovascular endurance and maximal strength suggest the possibility of producing gene chips to derive genotypes unique to “ Koreans” in the future. Additionally, this study provides important basic data for further research.
Evaluating muscular strength is vital to the application of effective training protocols that target quality of life and independence in older individuals. Resistance training is a valuable tool to ...improve functional capacity, strength, and power in this population; however, the lack of normative values for common lifts such as the leg press (LP) and chest press (CP) reduce its utility. This study developed age- and sex-specific normative strength values for older individuals. LP and CP 1-repetition maximum (1RM) values on Keiser A420 pneumatic machines were compiled from 445 older adults, ages 60-85y. Descriptive statistics and quartile rankings are reported, and two-way ANOVAs were conducted to determine differences between sex and age groups. There were significant sex x age group interactions for LP and CP. Men were significantly stronger than women across all age groups for both exercises (p < .01); however, the mean difference decreased with age. For men, no differences were seen among the 60–64 (237 ± 39 kg), 65–69 (223 ± 43 kg) and 70–74 (219 ± 50 kg) age groups; but the 60–64 group showed higher strength values than the 75–79 group (193 ± 52 kg) and all three groups contained higher strength values than the 80–85 group (172 ± 40 kg). Similarly, for relative strength, the 60–64 group (2.80 ± 0.53 kg·kgBM) surpassed values for all groups but the 65–69, and the 65–69 (2.70 ± 0.54 kg·kgBM) produced greater strength values than the 70–74 (2.45 ± 0.47 kg·kgBM), 75–79 (2.09 ± 0.37 kg·kgBM) and 80–85 (2.19 ± 0.38 kg·kgBM) groups. In contrast, no significant differences in absolute or relative strength were seen among age groups for the women. Our study establishes absolute and relative age- and sex-specific normative values for the LP1RM and CP1RM in older individuals. These values allow practitioners and researchers to interpret the results of various interventions, and evaluate their importance to evaluation of sarcopenia, injury risk, functional mobility and quality of life. Additionally, our results reveal that age-related declines in strength are prominent for male LP and CP, but not female CP or LP.
•Absolute and relative leg & chest press strengths decrease significantly with aging.•Men are significantly stronger than women across all age groups (60–85).•The mean difference between sexes decreases with age.•Male absolute and relative strengths differed significantly across age groups.•No significant differences for women's strengths were found by age group.
Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load-velocity relationship to predict the 1RM back squat. J Strength Cond Res 31(7): 1897-1904, 2017-This study investigated the ...reliability and validity of the load-velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-trained males performed three 1RM assessments on 3 separate days. All repetitions were performed to full depth with maximal concentric effort. Predicted 1RMs were calculated by entering the mean concentric velocity of the 1RM (V1RM) into an individualized linear regression equation, which was derived from the load-velocity relationship of 3 (20, 40, 60% of 1RM), 4 (20, 40, 60, 80% of 1RM), or 5 (20, 40, 60, 80, 90% of 1RM) incremental warm-up sets. The actual 1RM (140.3 ± 27.2 kg) was very stable between 3 trials (ICC = 0.99; SEM = 2.9 kg; CV = 2.1%; ES = 0.11). Predicted 1RM from 5 warm-up sets up to and including 90% of 1RM was the most reliable (ICC = 0.92; SEM = 8.6 kg; CV = 5.7%; ES = -0.02) and valid (r = 0.93; SEE = 10.6 kg; CV = 7.4%; ES = 0.71) of the predicted 1RM methods. However, all predicted 1RMs were significantly different (p ≤ 0.05; ES = 0.71-1.04) from the actual 1RM. Individual variation for the actual 1RM was small between trials ranging from -5.6 to 4.8% compared with the most accurate predictive method up to 90% of 1RM, which was more variable (-5.5 to 27.8%). Importantly, the V1RM (0.24 ± 0.06 m·s) was unreliable between trials (ICC = 0.42; SEM = 0.05 m·s; CV = 22.5%; ES = 0.14). The load-velocity relationship for the full depth free-weight back squat showed moderate reliability and validity but could not accurately predict 1RM, which was stable between trials. Thus, the load-velocity relationship 1RM prediction method used in this study cannot accurately modify sessional training loads because of large V1RM variability.
Purpose: To examine the effects of unilateral resistance training on lower body power, muscular strength, and measures of core stability in resistance-trained college students. Methods: Participants ...(N=22; mean age= 19.86 ± 0.9 years) underwent 10 sessions of either unilateral (UL) or bilateral (BL) resistance training on three non-consecutive days per week for three weeks. Pre and post training outcome measures included one repetition maximum (1-RM) leg press for lower body strength, standing vertical jump (VJ) for lower body power, and double leg lowering (DLL), hip abduction isometric strength (HAIS), and Sorensen (SOR) tests for core stability. Results: There was a significant (p≤ 0.05) main effect of time across all variables, such that both groups improved scores on 1-RM leg press, VJ, DLL, HAIS, and SOR. Additionally, the magnitude of improvement (Cohen’s d) was larger in UL for all variables except VJ, which was larger in the BL group. Conclusion: This study adds to the growing body of literature investigating the effects of UL resistance training in athletic populations. Similar improvements following UL or BL resistance training suggest that both methods can effectively enhance strength, power, and core stability. UL training may potentially yield greater improvement of core stability variables.
INTRODUCTIONSkeletal muscle strength is reduced in patients with schizophrenia, contributing to their impaired physical health, functional performance, and potentially mental health challenges. ...Although short-term training programs have shown promising results, improving muscle strength and functional performance, it is unknown how exercise can be successfully integrated into the long-term clinical care of outpatients with schizophrenia.OBJECTIVETo investigate effects of strength training with adherence support in a collaborative care model.METHODSWe randomized 28 men and 20 women (mean ± SD, 35 ± 11 years) to leg press maximal strength training (MST) with 4 sets at 90 % of one repetition maximum (1RM) 2 × week, facilitated by municipal service and professional supervision (TG), or a control group (CG).RESULTSThe TG increased scaled leg press 1RM (0-3 months: 19 %; 0-6 months: 31 %, 0-12 months: 40 %, all p < .001, and 3-12 months: 18 %, p < .05) and power (0-3 months, 11 %; 0-6 months: 22 %, 0-12 months: 26 %, all p < .001, and 3-12 months: 13 %, p < .05) throughout the 1-year period compared to the CG. The increased muscle strength was accompanied by improved sit-to-stand performance (20 %) after 12 months (p < .001). Both groups also exhibited within-group improvements in walking work efficiency after 6 months (TG: 13 %; CG: 23 %) and 1 year (TG: 11 %; CG: 21 %, p < .01-0.05), but with no evident differences between the groups. Stair climbing performance remained unchanged.CONCLUSIONOur results reveal that strength training can successfully be integrated as a part of long-term clinical care of outpatients with schizophrenia, contributing to improved functional performance.
Different tempos of movement can be used during resistance training, but programming them is often a trial-and-error practice, as changing the speed at which the exercise is performed does not always ...correspond with the tempo at which the 1-repetition-maximum occurred. Therefore, the aim of this study was to determine the effect of different movement tempos during the bench press (BP) exercise on the one-repetition maximum (1RM) load. Ninety men (age = 25.8 ± 5.3 years, body mass = 80.2 ± 14.9 kg), with a minimum one year of resistance training experience took part in the study. Using a randomized crossover design, each participant completed the BP 1RM test with five different movement tempos: V/0/V/0, 2/0/V/0, 5/0/V/0, 8/0/V/0 and 10/0/V/0. Repeated measures ANOVA compared the differences between the 1RM at each tempo. The 1RM load was significantly greater during V/0/V/0 and 2/0/V/0 compared to 5/0/V/0, 8/0/V/0, and 10/0/V/0 (p < 0.01). Furthermore, the 1RM load was significantly greater during 5/0/V/0 compared to 8/0/V/0 and 10/0/V/0 (p < 0.01), but there were no differences between either V/0/V/0 and 2/0/V/0 (p = 0.92) or between 8/0/V/0 and 10/0/V/0 (p = 0.08). Therefore, different movement tempos used during training should be accompanied by their own tempo-specific 1RM testing, as slower eccentric phases significantly decrease maximal concentric performance. Furthermore, 1RM test procedures should include information about the movement tempo used during the test protocol. In addition, the standardization of the tempo should be taken into account in investigations that use the 1 RM test to assess the effects of any treatment on maximal muscle strength.
In animal studies long-term stretching interventions up to several hours per day have shown large increases in muscle mass as well as maximal strength. The aim of this study was to investigate the ...effects of a long-term stretching on maximal strength, muscle cross sectional area (MCSA) and range of motion (ROM) in humans.
52 subjects were divided into an Intervention group (IG,
= 27) and a control group (CG,
= 25). IG stretched the plantar flexors for one hour per day for six weeks using an orthosis. Stretching was performed on one leg only to investigate the contralateral force transfer. Maximal isometric strength (MIS) and 1RM were both measured in extended knee joint. Furthermore, we investigated the MCSA of IG in the lateral head of the gastrocnemius (LG) using sonography. Additionally, ROM in the upper ankle was investigated
the functional "knee to wall stretch" test (KtW) and a goniometer device on the orthosis. A two-way ANOVA was performed in data analysis, using the Scheffé Test as post-hoc test.
There were high time-effects (
= 0.003, ƞ² = 0.090) and high interaction-effect (
< 0.001, ƞ²=0.387) for MIS and also high time-effects (
< 0.001, ƞ²=0.193) and interaction-effects (
< 0.001, ƞ²=0,362) for 1RM testing. Furthermore, we measured a significant increase of 15.2% in MCSA of LG with high time-effect (
< 0.001, ƞ²=0.545) and high interaction-effect (
=0.015, ƞ²=0.406). In ROM we found in both tests significant increases up to 27.3% with moderate time-effect (
< 0.001, ƞ²=0.129) and high interaction-effect (
< 0.001, ƞ²=0.199). Additionally, we measured significant contralateral force transfers in maximal strength tests of 11.4% (
< 0.001) in 1RM test and 1.4% (
=0.462) in MIS test. Overall, there we no significant effects in control situations for any parameter (CG and non-intervened leg of IG).
We hypothesize stretching-induced muscle damage comparable to effects of mechanical load of strength training, that led to hypertrophy and thus to an increase in maximal strength. Increases in ROM could be attributed to longitudinal hypertrophy effects, e.g., increase in serial sarcomeres. Measured cross-education effects could be explained by central neural adaptations due to stimulation of the stretched muscles.
The adoption of resistance training (RT) programs has been shown to positively influence sports performance-related parameters. However, the chronic effects of maximal strength protocols on the ...performance of soccer players are not completely investigated. The aim of this study was to evaluate the effects of performing two repetition maximum (2RM) before a resistance training session on the physical performance of youth soccer players. Seventeen players (under-20 category) were allocated in one of the following groups: 2RM + resistance training group (2RM + RT,
= 8) and resistance training group (RTG,
= 9). Both groups performed the same RT protocol during experimental weeks. However, the 2RM + RT performed 1 set of 2RM for 4 exercises, previously to RT protocol. Pre and post intervention period, one repetition maximum of the back squat exercise (1RM
), sprint time (15m-sprint test), countermovement jump (CMJ), repeated sprint ability (RSA
and RSA
), and yo-yo intermittent recovery test level-2 (YYIRT2) were assessed. Total load lifted (TLL) during the experimental weeks was also collected. Significant increases in 1RM
(2RM + RT: +45.1%,
= 4.40; RTG: +32.3%,
= 1.84), 15m sprint (2RM + RT: -9.0%,
= 7.9; RTG: -8.8%%,
= 3.2), CMJ (2RM + RT: +2.3%,
= 0.17; RTG: +0.8%,
= 0.07), RSA
(2RM + RT: -2.4%,
= 0.6; RTG: -2.3%,
= 1.04), RSA
(2RM + RT: -2.9%,
= 1.33; RTG: -3.4%,
= 1.78), YYIRT2 (2RM + RT: +12.0%,
= 0.82; RTG: +12.1%,
= 0.63) (all
< 0,05) were observed for both groups on pre to post-intervention periods, with no significant difference between groups. Therefore, the 2RM + RT protocol did not promote additional increase on performance of young soccer players.
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