Power Training and Functional Performance in Middle Aged Women: A Pilot Study

International Journal of Exercise Science 9(3): 327-335, 2016. Muscular power is a key component of functional performance (FP) and fall risk reduction. The present study investigated the effect that power training with medicine balls had on body composition and FP in middle-age females. 10 women were divided into a control group (n=4, age=59.8+3.6) and an intervention group (n=6, age=59.5+3.6) in this 6-week study. The intervention group completed a medicine ball training program two times a week. Body composition and FP tests were administered prepost. Data was analyzed using a series of Wilcoxon Signed Ranks test and Cohen’s d test for effect size. The 6-week training program increased functional performance. The intervention group exhibited increases in the Up and Go test (p\u3c.05) (Cohen’s d=1.76), as well as maximum (p\u3c.05) (Cohen’s d=-1.52) and average (p\u3c.05) (Cohen’s d=-1.32) distance thrown on the seated medicine ball throw. Middle-aged females can experience significant improvements in functional abilities after 6 weeks of participation in a medicine ball training program that includes both resistance and power training

Effects of a pre-workout energy drink supplement on upper body muscular endurance performance

International Journal of Exercise Science 9(5): 667-676, 2016. The use of pre-workout beverages is becoming an increasingly common method of improving performance during exercise in athletic and recreationally active populations. Therefore, the purpose of this study was to investigate the effects of a commercially available energy drink on exercise performance. Thirty-one healthy males (n=23) and females (n=8) participated in this study and were separated into two groups: supplement (SU; n=16) or placebo (PL; n=15). Subjects visited the laboratory on 2 occasions separated by no more than 7 days. The first visit consisted of completing a push up to fatigue protocol (PUFP) without ingesting the pre-workout energy drink supplement (PWEDS). The second visit consisted of ingesting either a placebo or the PWEDS 30 minutes prior to completing the PUFP. Rate of perceived exertion (RPE) was recorded following each set of push-ups on both testing days. Also, participant’s height, weight, and body composition were collected. There was no significant differences at baseline in any variable between groups (p = \u3e.05). After the second testing session, both groups significantly improved total push-ups (PL Pre: 133.3 ±39.4, PL Post: 155.3 ± 54.1; SU Pre: 139.3 ± 58.5, SU Post: 161.3 ± 79.4; p=\u3c.001), and push-ups completed in each of the 3 sets (p=\u3c.001), when compared to baseline. Post-testing revealed no significant difference between groups in total push-ups completed or RPE at any time point, when compared to baseline. In conclusion, the commercially available PWEDS offered no additional ergogenic effects when compared to the placebo

Age Does Not Attenuate Maximal Velocity Adaptations in the Ipsilateral and Contralateral Limbs During Unilateral Resistance Training

This study examined the effects of unilateral resistance training (RT) on maximal velocity parameters in the ipsilateral and contralateral legs in young and older males. Young (n = 22; age = 21.55 ± 2.23 years) and older (n = 20; age = 65.10 ± 9.65 years) males were assigned to training or control groups. Unilateral isokinetic RT of the knee extensors was performed for 4 weeks. Peak velocity and acceleration were identified during a dynamic maximal voluntary contraction before (PRE), at Week 2 (MID), and after Week 4 (POST) of RT. Age-independent increases in peak velocity (1.5%) and acceleration (4.5%) were demonstrated at POST for the trained leg. For the untrained leg, acceleration increased (4.3%) at POST similarly between training groups. These findings provide evidence for the high degree of neuromuscular plasticity, regardless of age, during the early phase of RT, and the potential for cross education of acceleration

Cross-education: effects of age on rapid and maximal voluntary contractile characteristics in males

Purpose The purpose of this study was to determine the effect of age on the cross-education of rapid and maximal contractile properties for the knee extensors. Methods Young (n = 10; age = 21.1 ± 1.7 years) and older (n = 10; age = 65.3 ± 8.3 years) males performed unilateral isokinetic resistance training (RT) of the knee extensors for 4 weeks. Maximal voluntary isokinetic (45° s−1 and 300° s−1) and isometric testing was conducted for the trained and untrained leg before and after RT. Peak torque (PT) and acceleration were obtained from isokinetic testing as well as torque at 30 ms (TQ30) and 100 ms (TQ100) from the 45° s−1 contraction. PT and rate of torque development were recorded from the isometric contractions. Results Independent of age, isometric PT (10.1%; p = 0.006) as well as PT and acceleration at 300° s−1 (6.7%; p = 0.008 and 4.0%; p = 0.016, respectively) increased in the untrained leg. At 45° s−1, acceleration was increased (3.6%; p = 0.021), but PT remained unchanged (p = 0.227). TQ100 increased similarly between groups (4.5%; p = 0.014), but TQ30 increased only in the older group (9.5%; p = 0.022). Conclusions Cross-education of rapid and maximal contractile parameters can be achieved early during unilateral RT independent of age. These findings indicate the potential for particular unilateral RT protocols to be used for older adults in rehabilitative settings to offset disuse-related reductions in contractile function, which are most dramatic in this population

Creatine and Resistance Training: A Combined Approach to Attenuate Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a potent chemotherapy agent, useful in the treatment of solid tumors, lymphomas, and leukemias, is limited by its potentially lethal cardiotoxicity. However, exercise has been consistently shown to mitigate the side effects of DOX, including cardiotoxicity. To date, most studies examining the relationship between exercise and DOX-induced cardiotoxicity have focused on aerobic exercise, with very few examining the role of anerobic activity. Therefore, this investigation explored the potential of creatine (CR) and resistance training (RT) in preserving cardiac health during DOX therapy. Male Sprague-Dawley rats were grouped into RT, RT + CR, sedentary (SED), and SED + CR, with each division further branching into saline (SAL) or DOX-treated subsets post-10 weeks of RT or SED activity. RT comprised progressive training utilizing specialized cages for bipedal stance feeding. CR-treated groups ingested water mixed with 1% CR monohydrate and 5% dextrose, while control animals received 5% dextrose. At week 10, DOX was administered (2 mg/kg/week) over 4-weeks to an 8 mg/kg cumulative dose. Cardiac function post-DOX treatment was assessed via transthoracic echocardiography. Left ventricular diameter during diastole was lower in DOX + CR, RT + DOX, and RT + CR + DOX compared to SED + DOX (p p < 0.05). These results suggest RT and CR supplementation, separately and in combination, could attenuate some measures of DOX-induced cardiotoxicity and may offer a cost-effective way to complement cancer treatments and enhance patient outcomes. More investigations are essential to better understand CR’s prolonged effects during DOX therapy and its clinical implications

CHANGES IN SURFACE ELECTROMYOGRAPHY AND RATE OF FORCE DEVELOPMENT FOLLOWING MAXIMAL ECCENTRIC AND CONCENTRIC EXERCISE

BACKGROUND: The purpose of this study was to examine the time-course in recovery of rapid force characteristics following maximal eccentric (ECC) or concentric (CON) contractions. METHODS: Seventeen strength-trained college-aged males completed this randomized, cross-over study. Subjects completed 6 sets of 10 repetitions of maximal unilateral ECC or CON contractions of the elbow flexors on an isokinetic dynamometer at 60°/s with 2 min rest between sets. Peak rate of force development (pRFD) and peak rate of electromyography (EMG) rise (pRER) were assessed instantaneously during a 10 ms window during a maximal voluntary isometric contraction (MVIC) at 90° of elbow flexion before (PRE), immediately after (POST), 1-hour (POST1), 24- (POST24), 48- (POST48), and 72-hours (POST72) post-exercise. Separate 2 (condition) × 6 (time) repeated measures ANOVAs were run for each dependent variable. RESULTS: There was no significant interaction effect for pRFD (p=0.257), however, there were significant main effects for condition (p=0.001) and time (p\u3c0.001). Post-hoc analysis revealed that when collapsed across time, pRFD was significantly lower in ECC (2681.7±725.1 N s-1) than CON (3063.1±673.6 N s-1; p=0.001). When collapsed across condition, pRFD was significantly greater at PRE (3754.0±1366.5 N⸱s-1) when compared to all other time points (p\u3c0.001-0.002). pRFD was reduced at POST (2337.5±679.9 N s-1) and POST1 (2454.4±788.1 N s-1) when compared to POST24 (2866.9±887.9 N s-1; p=0.001-0.012), POST48 (2907.6±1128.7 N s-1; p=0.007-0.027), and POST72 (2914.0±1014.9 N s-1; p=0.003-0.005). There was a significant interaction effect for pRER (p=0.028) by which, during ECC, pRER decreased from PRE (1.06±0.61 mV/s) to POST (0.77±0.41 mV/s; p=0.051), remained depressed at POST1 (0.72±0.48 mV/s; p=0.004) before recovering to baseline at POST24 (1.11±0.61 mV/s; p=0.033), which did not differ from POST48 (1.03±0.63 mV/s; p=0.863) or POST72 (1.15±0.47 mV/s; p=0.645). pRER was significantly lower in ECC at POST and POST1 when compared to CON (POST: 0.98±0.41 mV/s; POST1: 1.09±0.63 mV/s; p=0.043-0.048). During CON, pRER was significantly greater at PRE (1.35±0.87 mV/s) when compared to POST72 (0.95±0.47 mV/s; p=0.035). CONCLUSIONS: The findings of the present study suggest that pRER may be more sensitive than pRFD at discriminating contraction-specific changes in neuromuscular function following an acute bout of exercise

A description and comparison of cardiorespiratory fitness measures in relation to pitching performance among professional baseball pitchers

The purpose of this study is to provide descriptive and comparative information regarding the cardiorespiratory fitness of professional baseball pitchers. Twenty-four (n = 24) major league (ML) baseball pitchers (starters n = 14; relievers n = 10) over seven seasons (2007–2013) were evaluated. A modified Bruce protocol and the CardioCoach™ CO2 metabolic analyzer were used to estimate VO2 max and anaerobic threshold (AT) at the beginning of each season. Performance data from each season was utilized to draw inference about pitching performance. One-way Analysis of Variance (ANOVA) was used to compare Starting (S) and Relief (R) pitchers above/below the group mean for VO2 max and AT. Pearson product moment correlations were also used to examine relationships between cardiorespiratory fitness and performance. Significant differences in performance were discovered between S pitchers above/below the overall group mean for VO2 max. (p ≤ 0.05) and for AT in Walks plus Hits per Inning Pitched (WHIP) (p ≤ 0.05) and Earned Run Average (ERA) (p ≤ 0.05). Significant relationships between VO2 max and Walks per 9 Innings (BB/9) (p ≤ 0.05), Home Runs per 9 innings (HR/9) (p ≤ 0.05), Wins (W) (p ≤ 0.05), Fielding Independent Pitching (FIP) (p ≤ 0.01), Strikeouts (K) (p ≤ 0.01), Hits per 9 innings (H/9) (p ≤ 0.01), Strikeouts per 9 innings (K/9) (p ≤ 0.01), ERA (p ≤ 0.01), and WHIP (p ≤ 0.01). Low, but significant, correlations were discovered between AT and WHIP (p ≤ 0.05) and ERA (≤0.05). CONCLUSION: Higher aerobic capacity appears to be more influential for S than R pitchers. Strength and conditioning practitioners should ensure that pitchers, especially S pitchers at the ML level, perform sufficient and appropriate endurance training to support pitching performance