Effects of Creatine Supplementation and Three Days of Resistance Training on Muscle Strength, Power Output, and Neuromuscular Function

Abstract

Previous studies have demonstrated increases in peak torque (PT) and decreases in acceleration time (ACC) after only 2 days of resistance training, and other studies have reported improvements in isokinetic performance after 5 days of creatine supplementation. Consequently, there may be a combined benefit of creatine supplementation and short-term resistance training for eliciting rapid increases in muscle strength, which may be important for short-term rehabilitation and return-to-play for previously injured athletes. The purpose of this study, therefore, was to examine the effects of 3 days of isokinetic resistance training combined with 8 days of creatine monohydrate supplementation on PT, mean power output (MP), ACC, surface electromyography (EMG), and mechanomyography (MMG) of the vastus lateralis muscle during maximal concentric isokinetic leg extension muscle actions. Twenty-five men (mean age +/- SD = 21 +/- 3 years, stature = 177 +/- 6 cm, and body mass = 80 +/- 12 kg) volunteered to participate in this 9-day, double-blind, placebo-controlled study and were randomly assigned to either the creatine (CRE; n = 13) or placebo (PLA; n = 12) group. The CRE group ingested the treatment drink (280 kcal; 68 g carbohydrate; 10.5 g creatine), whereas the PLA group received an isocaloric placebo (70 g carbohydrate). Two servings per day (morning and afternoon) were administered in the laboratory on days 1-6, with only 1 serving on days 7-8. Before (pre; day 1) and after (post; day 9) the resistance training, maximal voluntary concentric isokinetic leg extensions at 30, 150, and 270 degrees x s(-1) were performed on a calibrated Biodex System 3 dynamometer. Three sets of 10 repetitions at 150 degrees x s(-1) were performed on days 3, 5, and 7. Peak torque increased (p = 0.005; eta(2) = 0.296), whereas ACC decreased (p < 0.001; eta(2) = 0.620), from pretraining to posttraining for both the CRE and PLA groups at each velocity (30, 150, and 270 degrees x s(-1)). Peak torque increased by 13% and 6%, whereas ACC decreased by 42% and 34% for the CRE and PLA groups, respectively, but these differences were not statistically significant (p > 0.05). There were no changes in MP, EMG, or MMG amplitude; however, EMG median frequency (MDF) increased, and MMG MDF increased at 30 degrees x s(-1), from pretraining to posttraining for both the CRE and PLA groups. These results indicated that 3 days of isokinetic resistance training was sufficient to elicit small, but significant, improvements in peak strength (PT) and ACC for both the CRE and PLA groups. Although the greater relative improvements in PT and ACC for the CRE group were not statistically significant, these findings may be useful for rehabilitation or strength and conditioning professionals who may need to rapidly increase the strength of a patient or athlete within 9 days.

Novel insights into skeletal muscle function by mechanomyography: from the laboratory to the field

“…All works used a PIZ to detect MMG signal. Two studies analysed the quadriceps muscle [26,87], while the other two analysed the biceps brachii [88] and the plantar flexors muscles [25], respectively.…”

“…Cramer et al [25] assessed the effects of 3 days of isokinetic resistance training combined with 8 days of creatine monohydrate supplementation on peak torque, mean power output, acceleration time, and EMG and MMG signals of the vastus lateralis muscle during maximal concentric isokinetic leg extension actions. A group of 25 young men were randomly assigned to either the creatine or the placebo group.…”

“…The application fields of MMG are numerous and increasing: they span from the assessment of muscle function during isometric or dynamic contractions under different physiological conditions, such as fatigue [16][17][18], muscle temperature manipulation [19,20], stretching [21][22][23], ageing [24], training [25,26], to the analysis of the effects of rehabilitation programs [27,28], the development of prosthesis [29], and/or the use of the MMG as a triggering signal [30].…”

Effects of short‐term resistance training and subsequent detraining on the electromechanical delay

“…increase muscle strength after only days of training. [1][2][3][4] However, these studies have used isokinetic (ISOK) training modes, which are not as accessible, convenient, cost-effective, or practical for the general population as dynamic constant external resistance (DCER). Research suggests early adaptations to resistance training programs are related to improvements in neuromuscular efficiency, which may indicate an increased capacity to activate skeletal muscle voluntarily.…”

“…Research suggests early adaptations to resistance training programs are related to improvements in neuromuscular efficiency, which may indicate an increased capacity to activate skeletal muscle voluntarily. [1][2][3]5,6 Nevertheless, the specific mechanisms of such adaptations in short-term training are not fully understood. 3 Enoka 7 suggested adaptations in the connective tissue may improve force transmittal from the sarcomere to the skeletal system.…”