Abstract:
:The purpose of this study was to describe the physiological profile of responders (>20 mmol.kg(-1) dry weight [dw] increase in total intramuscular creatine monohydrate [Cr] + phosphorylated creatine [PCr]) versus nonresponders (<10 mmol.kg(-1) dw increase) to a 5-day Cr load (0.3 g.kg(-1).d(-1)) in 11 healthy men (mean age = 22.7 years). Pre-post 5-day cellular measures included total resting Cr content (Cr + PCr), fiber type composition, and fiber type cross-sectional area (CSA) determined from muscle biopsies of the vastus lateralis. Body mass, daily dietary intake, 24-hour urine outputs, urinary Cr and creatinine (CrN), and strength performance measures (1 repetition maximum [1RM] bench and leg press) were also assessed before and after the 5-day loading period. Results indicated that there were 3 levels of response to the 5-day supplementation: responders (R), quasi responders (QR), and nonresponders (NR) with mean changes in resting Cr + PCr of 29.5 mmol.kg(-1) dw (n = 3), 14.9 mmol.kg(-1) dw (n = 5), and 5.1 mmol.kg(-1) dw (n = 3), respectively. The results support a person-by-treatment interaction to acute Cr supplementation with R possessing a biological profile of lowest initial levels of Cr + PCr, greatest percentage of type II fibers, and greatest preload muscle fiber CSA and fat-free mass. Responders also showed improvement in 1RM leg press scores following the 5-day loading period. NR had higher preload levels of Cr + PCr, less type II muscle fibers, small preload muscle CSA, and lower fat-free mass and displayed no improvements in 1RM strength scores. The results suggest that to be considered a responder to acute oral supplementation, a favorable preexisting biological profile may determine the final extent to which an individual responds to supplementation. Physiologic profiles of nonresponders appear to be different and may limit their ability to uptake Cr. This may help partially explain the reported equivocal performance findings in the Cr supplementation literature.
journal_name
J Strength Cond Resjournal_title
Journal of strength and conditioning researchauthors
Syrotuik DG,Bell GJdoi
10.1519/12392.1keywords:
subject
Has Abstractpub_date
2004-08-01 00:00:00pages
610-7issue
3eissn
1064-8011issn
1533-4287pii
12392journal_volume
18pub_type
临床试验,杂志文章,随机对照试验abstract::In this study, we evaluated the efficacy of two different dynamic warm-up conditions, one that was inclusive of open skills (i.e., reactive movements) and one that included only preplanned dynamic activities (i.e., closed skills) on the performance of speed, change of direction speed, vertical jump, and reactive agili...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,随机对照试验
doi:10.1519/JSC.0b013e3181739ecd
更新日期:2008-09-01 00:00:00
abstract::Elastic bands added to traditional free-weight techniques have become a part of suggested training routines in recent years. Because of the variable loading patterns of elastic bands (i.e., greater stretch produces greater resistance), it is necessary to quantify the exact loading patterns of bands to identify the vol...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e318199d963
更新日期:2010-01-01 00:00:00
abstract::Lipford, GF, Evans, RK, Acevedo, EO, Wolfe, LG, and Franco, RL. Excess blood flow response to acute resistance exercise in individuals who are obese or nonobese. J Strength Cond Res 31(11): 3120-3127, 2017-Resistance exercise (RE) is a commonly recommended treatment option for obese individuals. However, little is kno...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000001748
更新日期:2017-11-01 00:00:00
abstract::The purpose of this experiment was to examine the effects of concurrent endurance and explosive strength training on electromyography (EMG) and force production of leg extensors, sport-specific rapid force production, aerobic capacity, and work economy in cross-country skiers. Nineteen male cross-country skiers were a...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/R-20045.1
更新日期:2007-05-01 00:00:00
abstract::Fonseca Alves, DJ, Bartholomeu-Neto, J, Júnior, ER, Ribeiro Zarricueta, BS, Nóbrega, OT, and Córdova, C. Walking speed, risk factors, and cardiovascular events in older adults-systematic review. J Strength Cond Res 31(11): 3235-3244, 2017-It is important that new clinical measures can identify risk factors and predict...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,评审
doi:10.1519/JSC.0000000000002182
更新日期:2017-11-01 00:00:00
abstract::Chandler, PT, Greig, M, Comfort, P, and McMahon, JJ. Variability of plyometric and ballistic exercise technique maintains jump performance. J Strength Cond Res 32(6): 1571-1582, 2018-The aim of this study was to investigate changes in vertical jump technique over the course of a training session. Twelve plyometric and...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000002572
更新日期:2018-06-01 00:00:00
abstract::We tested the null hypothesis that creatine monohydrate loading (20 g per day for 7 days, n = 18) would not alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with loading with placebo (n = 13) in resistance-trained subjects. For the e...
journal_title:Journal of strength and conditioning research
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:2001-11-01 00:00:00
abstract::The purpose of this study was to compare shoulder range-of-motion (ROM) and strength values between bodybuilders and nonbodybuilders. Fifty-four men (29 bodybuilders and 25 nonbodybuilders) between the ages of 21 and 34 years participated in the study. Goniometric measurements were used to assess shoulder flexion and ...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:
更新日期:2002-08-01 00:00:00
abstract::Barbell back squats are a popular exercise for developing lower extremity strength and power. However, this exercise has potential injury risks, particularly to the lumbar spine, pelvis, and hip joint. Previous literature suggests heel wedges as a means of favorably adjusting trunk and pelvis kinematics with the inten...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000001655
更新日期:2017-06-01 00:00:00
abstract::The purpose of this study was to examine the affective responses to acute resistance exercise (RE) performed at self-selected (SS) and imposed loads in recreationally trained women. Secondary purposes were to (a) examine differences in correlates of motivation for future participation in RE and (b) determine whether a...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000000985
更新日期:2015-11-01 00:00:00
abstract::This study examined lower extremity power performance, using the Margaria-Kalamen Power Test, after a dynamic warm-up with (resisted) and without (nonresisted) a weighted vest. Sixteen (n = 16) high school male football players, ages 14-18 years, participated in 2 randomly ordered testing sessions. One session involve...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e3181f159bd
更新日期:2010-12-01 00:00:00
abstract::To investigate the positional physical requirements necessary to be drafted into the National Football League (NFL), data from the annual NFL combine over the years 2005-2009 were examined. Only those players invited to the combine and subsequently drafted in the same year (n = 1,136) were included in the study. Data ...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e318208ae3f
更新日期:2011-10-01 00:00:00
abstract::Strength and conditioning training programs are essential components of athletic performance, and the effectiveness of these programs can be linked to the strength and conditioning facilities (SCFs) used by athletes. The primary purpose of this study was to provide a statistical overview of National Collegiate Athleti...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000000368
更新日期:2014-08-01 00:00:00
abstract::Previous research has shown that static stretching (SS) can diminish the peak force output of stretch-shortening cycle actions while performing a dynamic warm-up (DW) protocol has been shown to enhance performance in similar activities. The purpose of this study was to establish whether the deleterious effects of SS w...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e31815ef202
更新日期:2008-01-01 00:00:00
abstract::The purposes of this study were firstly to investigate whether learning affects were present in the administration of 4 hop tests and the Agility T-test and secondly to assess the between-session reliability of these tests. Twenty-two recreational athletes (11 women: age 22.3 ± 3.7 years, height 167.7 ± 6.2 cm, weight...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e3181d83335
更新日期:2011-05-01 00:00:00
abstract::Khan, FL, Lawal, JM, Kapture, DO, Swingle, JD, and Malek, MH. Revisiting the single-visit protocol for determining the electromyographic fatigue threshold. J Strength Cond Res 31(12): 3503-3507, 2017-The electromyographic fatigue threshold (EMGFT) has been shown to demarcate between nonfatiguing and fatiguing exercise...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000002274
更新日期:2017-12-01 00:00:00
abstract::Implementing objective methods to assess physical performance has become an invaluable component of athlete or player development, monitoring, and talent identification in distinct sports. Many sports depend heavily upon muscular strength, muscle power output, and sprint performance, especially at competition level. T...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000000390
更新日期:2014-08-01 00:00:00
abstract::The purpose of this study was to examine the effect of 2 different intervention training regimes on VO2max, VO2max velocity (vVO2max), running economy (RE), lactic threshold velocity (vLT), and running performance on a group of well-trained male middle-distance runners in the precompetition period. Twenty-six well-tra...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,随机对照试验
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更新日期:2011-03-01 00:00:00
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journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000000497
更新日期:2014-10-01 00:00:00
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journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000003907
更新日期:2021-02-01 00:00:00
abstract::Injuries are the leading cause of medical encounters across the U.S. military services resulting in more than 2.0 million clinic visits per year. Almost 50% of military service members experience an injury each year and half of those injuries are caused by physical training (PT), exercise, or sports. To prevent a prob...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,评审
doi:10.1519/JSC.0000000000001115
更新日期:2015-11-01 00:00:00
abstract::McClelland, JM, Godek, SF, Chlad, PS, Feairheller, DL, and Morrison, KE. Effects of cardiovascular fitness and body composition on maximal core temperature in collegiate football players during preseason. J Strength Cond Res 32(6): 1662-1670, 2018-This study evaluated the effects of body mass index (BMI) and aerobic f...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000002027
更新日期:2018-06-01 00:00:00
abstract::A bout of eccentric exercise (ECC) has the protective effect of reducing muscle damage during a subsequent bout of ECC known as the "repeated bout effect" (RBE). The purpose of this study was to determine if the RBE is greater when both bouts of ECC are performed using the same vs. different velocity of contraction. T...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0b013e31829d23dd
更新日期:2014-02-01 00:00:00
abstract::Our study purpose examined salivary hormonal responses to high-speed resistive exercise. Healthy subjects (n = 45) performed 2 elbow flexor workouts on a novel (inertial kinetic exercise; Oconomowoc, WI, USA) strength training device. Our methods included saliva sample collection at both preexercise and immediately po...
journal_title:Journal of strength and conditioning research
pub_type: 临床试验,杂志文章
doi:10.1519/JSC.0b013e31822c7267
更新日期:2012-03-01 00:00:00
abstract::Soldiers are often required to carry heavy loads during military operations. This article reports on a systematic literature review examining the influence of physical training on load carriage performance. Several literature databases, reference lists, and other sources were explored to find studies that quantitative...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,meta分析,评审
doi:10.1519/JSC.0b013e3182429853
更新日期:2012-02-01 00:00:00
abstract::Team handball is an Olympic sport played professionally in many European countries. Nevertheless, a scientific knowledge regarding women's elite team handball demands is limited. Thus, the purpose of this article was to review a series of studies (n = 33) on physical characteristics, physiological attributes, physical...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,评审
doi:10.1519/JSC.0b013e3182891535
更新日期:2013-06-01 00:00:00
abstract::In practice, the Bruce protocol is the most commonly used treadmill protocol to assess maximal oxygen consumption (V(.-)O2max). It has been suggested that a running protocol (e.g., Astrand) may elicit a comparatively higher V(.-)O2max and different cardiorespiratory responses when applied to moderately trained runners...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,随机对照试验
doi:10.1519/R-21176.1
更新日期:2007-11-01 00:00:00
abstract::The primary objective of this study was to assess the relationship between aerobic capacity, as measured by the VO(2)max test, and recovery from high-intensity intermittent exercise. Eleven female collegiate hockey players agreed to participate. Subjects skated 5 1-lap intervals around the hockey rink at maximal inten...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/R-18881.1
更新日期:2007-08-01 00:00:00
abstract::Concurrent training (CT) seems to impair training-induced muscle hypertrophy. This study compared the effects of CT, strength training (ST) and interval training (IT) on the muscle fiber cross-sectional area (CSA) response, and on the expression of selected genes involved in the myostatin (MSTN) signaling mRNA levels....
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章,随机对照试验
doi:10.1519/JSC.0000000000000525
更新日期:2014-11-01 00:00:00
abstract::The purpose of this study was to examine the relationship between the fatigue index from an isokinetic fatigue test and the velocity-related decrease in peak torque for the forearm flexors. After a familiarization session, 13 habitually active males (mean ± SD, age = 23.8 ± 3.1 years) reported to the laboratory to per...
journal_title:Journal of strength and conditioning research
pub_type: 杂志文章
doi:10.1519/JSC.0000000000000879
更新日期:2015-08-01 00:00:00