The effect of a combined high-intensity strength and speed training program on the running and jumping ability of soccer players

The purpose of this study was to investigate the effect of a combined heavy-resistance and running-speed training program performed in the same training session on strength, running velocity (RV), and vertical-jump performance (VJ) of soccer players. Thirty-five individuals were divided into 3 groups. The first group (n = 12, COM group) performed a combined resistance and speed training program at the same training session, and the second one (n = 11, STR group) performed the same resistance training without speed training. The third group was the control group (n = 12, CON group). Three jump tests were used for the evaluation of vertical jump performance: squat jump, countermovement jump, and drop jump. The 30-m dash and 1 repetition maximum (1RM) tests were used for running speed and strength evaluation, respectively. After training, both experimental groups significantly improved their 1RM of all tested exercises. Furthermore, the COM group performed significantly better than the STR and the CON groups in the 30-m dash, squat jump, and countermovement jump. It is concluded that the combined resistance and running-speed program provides better results than the conventional resistance training, regarding the power performance of soccer players.     

Effects of resistance training on the physical capacities of adolescent soccer players

This study examined the effects of a progressive resistance training program in addition to soccer training on the physical capacities of male adolescents. Eighteen soccer players (age: 12-15 years) were separated in a soccer (SOC; n = 9) and a strength-soccer (STR; n = 9) training group and 8 subjects of similar age constituted a control group. All players followed a soccer training program 5 times a week for the development of technical and tactical skills. In addition, the STR group followed a strength training program twice a week for 16 weeks. The program included 10 exercises, and at each exercise, 2-3 sets of 8-15 repetitions with a load 55-80% of 1 repetition maximum (1RM). Maximum strength ([1RM] leg press, bench-press), jumping ability (squat jump [SJ], countermovement jump [CMJ], repeated jumps for 30 seconds) running speed (30 m, 10 x 5-m shuttle run), flexibility (seat and reach), and soccer technique were measured at the beginning, after 8 weeks, and at the end of the training period. After 16 weeks of training, 1RM leg press, 10 x 5-m shuttle run speed, and performance in soccer technique were higher (p < 0.05) for the STR and the SOC groups than for the control group. One repetition maximum bench press and leg press, SJ and CMJ height, and 30-m speed were higher (p < 0.05) for the STR group compared with SOC and control groups. The above data show that soccer training alone improves more than normal growth maximum strength of the lower limps and agility. The addition of resistance training, however, improves more maximal strength of the upper and the lower body, vertical jump height, and 30-m speed. Thus, the combination of soccer and resistance training could be used for an overall development of the physical capacities of young boys.     

Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women

Twenty-four women completed a 20-week heavy-resistance weight training program for the lower extremity. Workouts were twice a week and consisted of warm-up exercises followed by three sets each of full squats, vertical leg presses, leg extensions, and leg curls. All exercises were performed to failure using 6-8 RM (repetition maximum). Weight training caused a significant increase in maximal isotonic strength (1 RM) for each exercise. After training, there was a decrease in body fat percentage (p less than 0.05), and an increase in lean body mass (p less than 0.05) with no overall change in thigh girth. Biopsies were obtained before and after training from the superficial portion of the vastus lateralis muscle. Sections were prepared for histological and histochemical examination. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were distinguished following routine myofibrillar adenosine triphosphatase histochemistry. Areas were determined for fiber types I, IIA, and IIAB + IIB. The heavy-resistance training resulted in significant hypertrophy of all three groups: I (15%), IIA (45%), and IIAB + IIB (57%). These data are similar to those in men and suggest considerable hypertrophy of all major fiber types is also possible in women if exercise intensity and duration are sufficient. In addition, the training resulted in a significant decrease in the percentage of IIB with a concomitant increase in IIA fibers, suggesting that strength training may lead to fiber conversions.     

Effect of static stretching of the biceps brachii on torque,electromyography, and mechanomyography during concentric isokinetic muscle actions

The purpose of this study was to determine the effect of an acute static stretching bout of the biceps brachii on torque, electromyography (EMG), and mechanomyography (MMG) during concentric isokinetic muscle actions. Eighteen (men, n = 10; women, n = 8) adult subjects (M +/- SD age = 22.7 +/- 2.8 years; weight = 78.0 +/- 17.0 kg; height = 177.9 +/- 11.0 cm) performed maximal isokinetic (30 and 270 degrees.s(-1)) forearm flexion strength testing on 2 occasions while EMG and MMG were recorded. Subjects were randomly assigned to stretching (STR) or nonstretching (NSTR) protocols before strength testing. Two-way ANOVAs with repeated measures revealed significantly (p < or = 0.05) greater torque for NSTR (M +/- SEM = 36.9 +/- 3.3 N.m) vs. STR (35.2 +/- 3.3 N.m), significantly greater MMG amplitude for STR vs. NSTR for 30 degrees.s(-1) (STR = 93.5 +/- 14.4 mV; NSTR = 63.1 +/- 10.6 mV) and 270 degrees.s(-1) (STR = 207.6 +/- 35.6 mV; NSTR = 136.4 +/- 31.7 mV), and no difference in EMG amplitude. These results indicate that a greater ability to produce torque without prior stretching is related to the musculotendinous stiffness of the muscle rather than the number of motor units activated. This suggests that performing activities that reduce muscle stiffness (such as stretching), may be detrimental to performance.     

Myostatin gene expression is reduced in humans with heavy-resistance strength training: a brief communication

This study examined changes in myostatin gene expression in response to strength training (ST). Fifteen young and older men (n = 7) and women (n = 8) completed a 9-week heavy-resistance unilateral knee extension ST program. Muscle biopsies were obtained from the dominant vastus lateralis before and after ST. In addition to myostatin mRNA levels, muscle volume and strength were measured. Total RNA was reverse transcribed into cDNA, and myostatin mRNA was quantified using quantitative PCR by standard fluorescent chemistries and was normalized to 18S rRNA levels. A 37% decrease in myostatin expression was observed in response to ST in all subjects combined (2.70 +/- 0.36 vs 1.69 +/- 0.18 U, arbitrary units; P < 0.05). Though the decline in myostatin expression was similar regardless of age or gender, the small number of subjects in these subgroups suggests that this observation needs to be confirmed. No significant correlations were observed between myostatin expression and any muscle strength or volume measure. Although further work is necessary to clarify the findings, these data demonstrate that myostatin mRNA levels are reduced in response to heavy-resistance ST in humans.     

Effects of a heart rate-based recovery period on hormonal, neuromuscular, and aerobic performance responses during 7 weeks of strength training in men

The purpose of this study was to compare hormonal, neuromuscular, and aerobic performance changes between a constant 2-minute interset recovery time and an interset recovery time based on individual heart rate (HR) responses during a 7-week (3 sessions per week, 3 × 10 repetition maximum [RM]) hypertrophic strength training period. The HR-dependent recovery time was determined with a Polar FT80 HR monitor, whereas the control groups used constant 2-minute periods between sets. From 24 male subjects who were divided in 2 equal groups, 21 completed the study (FT80, n = 12; CONTROL, n = 9). Serum blood samples analyzed for testosterone (TES) and cortisol (COR) were taken before and after the 7-week training period at rest. Concentric knee extension 1RM was measured before, after 4 weeks, and at the end of the training period. Concentric knee extension and knee flexion 10RM, central activation ratio (CAR), and maxVO2 were measured before and after the training. Serum TES concentrations were significantly higher after the training period in FT80 (p < 0.001), whereas no significant changes were observed in the CONTROL. Serum COR and maxVO2 were unchanged in both groups. In FT80 (p < 0.001), the increase in 10RM was higher (p < 0.05) than in CONTROL (p < 0.001). Central activation ratio increased in both groups, with the significant increase observed in FT80 (p < 0.05). The higher TES responses, 10RM, and CAR development in FT80 suggest that an HR-based recovery period system of the FT80 may be more efficient in this type of hypertrophic strength training (3 × 10RM). The protocol in this study may be considered as a metabolic training cycle that coaches and trainers can use within a longer periodized training program.     

Relative vs. absolute physiological measures as predictors of mountain bike cross-country race performance

The aims of this study were to document the effect terrain has on the physiological responses and work demands (power output) of riding a typical mountain bike cross-country course under race conditions. We were particularly interested in determining whether physiological measures relative to mass were better predictors of race performance than absolute measures. Eleven A-grade male cross-country mountain bike riders (VO2max 67.1 +/- 3.6 ml x kg(-1) x min(-1)) performed 2 tests: a laboratory-based maximum progressive exercise test, and a 15.5-km (six 2.58-km laps) mountain bike cross-country time trial. There were significant differences among the speed, cadence, and power output measured in each of 8 different terrain types found in the cross-country time trial course. The highest average speed was measured during the 10-15% downhill section (22.7 +/- 2.6 km x h(-1)), whereas the cadence was highest in the posttechnical flat sections (74.3 +/- 5.6 rpm) and lowest on the 15-20% downhill sections (6.4 +/- 12.1 rpm). The highest mean heart rate (HR) was obtained during the steepest (15-20% incline) section of the course (179 +/- 8 b x min(-1)), when the power output was greatest (419.8 +/- 39.7 W). However, HR remained elevated relative to power output in the downhill sections of the course. Physiological measures relative to total rider mass correlated more strongly to average course speed than did absolute measures (peak power relative to mass r = 0.93, p < 0.01, vs. peak power r = 0.64, p < 0.05; relative VO2max r = 0.80, p < 0.05, vs. VO2max r = 0.66, p < 0.05; power at anaerobic threshold relative to mass r = 0.78, p < 0.05, vs. power at anaerobic threshold r = 0.5, p < 0.05). This suggests that mountain bike cross-country training programs should focus upon improving relative physiological values rather than focusing upon maximizing absolute values to improve performance.     

The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training

The purpose of this study was to examine the effects of whey protein supplementation on body composition, muscular strength, muscular endurance, and anaerobic capacity during 10 weeks of resistance training. Thirty-six resistance-trained males (31.0 +/- 8.0 years, 179.1 +/- 8.0 cm, 84.0 +/- 12.9 kg, 17.8 +/- 6.6%) followed a 4 days-per-week split body part resistance training program for 10 weeks. Three groups of supplements were randomly assigned, prior to the beginning of the exercise program, in a double-blind manner to all subjects: 48 g per day (g.d(-1)) carbohydrate placebo (P), 40 g.d(-1) of whey protein + 8 g.d(-1) of casein (WC), or 40 g.d(-1) of whey protein + 3 g.d(-1) branched-chain amino acids + 5 g.d(-1) L-glutamine (WBG). At 0, 5, and 10 weeks, subjects were tested for fasting blood samples, body mass, body composition using dual-energy x-ray absorptiometry (DEXA), 1 repetition maximum (1RM) bench and leg press, 80% 1RM maximal repetitions to fatigue for bench press and leg press, and 30-second Wingate anaerobic capacity tests. No changes (p > 0.05) were noted in all groups for energy intake, training volume, blood parameters, and anaerobic capacity. WC experienced the greatest increases in DEXA lean mass (P = 0.0 +/- 0.9; WC = 1.9 +/- 0.6; WBG = -0.1 +/- 0.3 kg, p < 0.05) and DEXA fat-free mass (P = 0.1 +/- 1.0; WC = 1.8 +/- 0.6; WBG = -0.1 +/- 0.2 kg, p < 0.05). Significant increases in 1RM bench press and leg press were observed in all groups after 10 weeks. In this study, the combination of whey and casein protein promoted the greatest increases in fat-free mass after 10 weeks of heavy resistance training. Athletes, coaches, and nutritionists can use these findings to increase fat-free mass and to improve body composition during resistance training.     

Effect of direct supervision of a strength coach on measures of muscular strength and power in young rugby league players

The purpose of the present study was to examine the influence of direct supervision on muscular strength, power, and running speed during 12 weeks of resistance training in young rugby league players. Two matched groups of young (16.7 +/- 1.1 years [mean +/- SD]), talented rugby league players completed the same periodized resistance-training program in either a supervised (SUP) (N = 21) or an unsupervised (UNSUP) (N = 21) environment. Measures of 3 repetition maximum (3RM) bench press, 3RM squat, maximal chin-ups, vertical jump, 10- and 20-m sprints, and body mass were completed pretest (week 0), midtest (week 6), and posttest (week 12) training program. Results show that 12 weeks of periodized resistance training resulted in an increased body mass, 3RM bench press, 3RM squat, maximum number of chin-ups, vertical jump height, and 10- and 20-m sprint performance in both groups (p < 0.05). The SUP group completed significantly more training sessions, which were significantly correlated to strength increases for 3RM bench press and squat (p < 0.05). Furthermore, the SUP group significantly increased 3RM squat strength (at 6 and 12 weeks) and 3RM bench press strength (12 weeks) when compared to the UNSUP group (p < 0.05). Finally, the percent increase in the 3RM bench press, 3RM squat, and chin-up(max) was also significantly greater in the SUP group than in the UNSUP group (p < 0.05). These findings show that the direct supervision of resistance training in young athletes results in greater training adherence and increased strength gains than does unsupervised training.     

Influence of strength training on adult women's flexibility

The purpose of the current study was to investigate the effect of 10 weeks of strength training on the flexibility of sedentary middle-aged women. Twenty women were randomly assigned to either a strength training group (n = 10; age, 37 +/- 1.7 years; body mass, 65.2 +/- 10.7 kg; height, 157.7 +/- 10.8 cm; and body mass index, 25.72 +/- 3.3 kg x m(-2)) or a control group (n = 10; age, 36.9 +/- 1.2 years; body mass, 64.54 +/- 10.18 kg; height, 158.1 +/- 8.9 cm; and body mass index, 26.07 +/- 2.8 kg x m(-2)). The strength training program was a total body session performed in a circuit fashion and consisted of 7 exercises performed for 3 circuits of 8 to 12 repetitions maximum (RM), except for the abdominal exercise which was performed for 15 to 20 RM. Flexibility measurements were taken for 10 articulation movements pre and post training: shoulder flexion and extension, shoulder horizontal adduction and abduction, elbow flexion, hip flexion and extension, knee flexion, and trunk flexion and extension. Pre and post training, 10 RM strength significantly increased (p < 0.05). Of the movements examined, only shoulder horizontal adduction, hip flexion and extension, and trunk flexion and extension demonstrated significant increases (p < 0.05). Neither elbow nor knee flexion showed a significant change with weight training. The control group showed no significant change in any of the flexibility measures determined. In conclusion, weight training can increase flexibility in previously sedentary middle-aged women in some, but not all joint movements.     

Plasma MicroRNA Levels Differ between Endurance and Strength Athletes

Aim

MicroRNAs (miRNAs) are stable in the circulation and are likely to function in inter-organ communication during a variety of metabolic responses that involve changes in gene expression, including exercise training. However, it is unknown whether differences in circulating-miRNA (c-miRNA) levels are characteristic of training modality.

Methods

We investigated whether levels of candidate c-miRNAs differ between elite male athletes of two different training modalities (n = 10 per group) - endurance (END) and strength (STR) - and between these groups and untrained controls (CON; n = 10). Fasted, non-exercised, morning plasma samples were analysed for 14 c-miRNAs (miR-1, miR-16-2, miR-20a-1, miR-21, miR-93, miR-103a, miR-133a, miR-146a, miR-192, miR-206, miR-221, miR-222, miR-451, miR-499). Moreover, we investigated whether c-miRNA levels were associated with quantitative performance-related phenotypes within and between groups.

Results

miR-222 was present at different levels in the three participant groups (p = 0.028) with the highest levels being observed in END and the lowest in STR. A number of other c-miRNAs were present at higher levels in END than in STR (relative to STR, ± 1 SEM; miR-222: 1.94 fold (1.73-2.18), p = 0.011; miR-21: 1.56 fold (1.39-1.74), p = 0.013; miR-146a: 1.50 fold (1.38-1.64), p = 0.019; miR-221: 1.51 fold (1.34-1.70), p = 0.026). Regression analyses revealed several associations between candidate c-miRNA levels and strength-related performance measures before and after adjustment for muscle or fat mass, but not following adjustment for group.

Conclusion

Certain c-miRNAs (miR-222, miR-21, miR-146a and miR-221) differ between endurance- and resistance-trained athletes and thus have potential as useful biomarkers of exercise training and / or play a role in exercise mode-specific training adaptations. However, levels of these c-miRNAs are probably unrelated to muscle bulk or fat reserves.     

Ankle and knee moment and power adaptations are elicited through load carriage conditioning in males

Soldiers routinely conduct load carriage and physical training to meet occupational requirements. These tasks are physically arduous and are believed to be the primary cause of musculoskeletal injury. Physical training can help mitigate injury risk when specifically designed to address injury mechanisms and meet task demands. This study aimed to assess lower-limb biomechanics and neuromuscular adaptations during load carriage walking in response to a 10-week evidence-based physical training program. Thirteen male civilian participants donned 23 kg and completed 5 km of load carriage treadmill walking, at 5.5 km h⁻¹ before and after a 10-week physical training program. Three-dimensional motion capture and force plate data were acquired in over-ground walking trials before and after treadmill walking. These data were inputs to a musculoskeletal model which estimated lower-limb joint kinematics and kinetics (i.e., moments and powers) using inverse kinematics and dynamics, respectively. A two-way analysis of variance revealed significant main effect of training for kinematic and kinetics parameters at the knee and ankle joints (p < 0.05). Post-Hoc comparisons demonstrated a significant decrease (4.2%) in total negative knee power between pre- and post-March 5 km measures after training (p < 0.05). Positive power contribution shifted distally after training, increasing at the post-march measure from 39.9% to 43.6% at the ankle joint (p < 0.05). These findings demonstrate that a periodised training program may reduce injury risk through favourable ankle and knee joint adaptations.     

Two-year home-based nocturnal noninvasive ventilation added to rehabilitation in chronic obstructive pulmonary disease patients: A randomized controlled trial

Background

The use of noninvasive intermittent positive pressure ventilation (NIPPV) in chronic obstructive pulmonary disease (COPD) patients with chronic hypercapnic respiratory failure remains controversial as long-term data are almost lacking.The aim was to compare the outcome of 2-year home-based nocturnal NIPPV in addition to rehabilitation (NIPPV + PR) with rehabilitation alone (PR) in COPD patients with chronic hypercapnic respiratory failure.

Methods

Sixty-six patients could be analyzed for the two-year home-based follow-up period. Differences in change between the NIPPV + PR and PR group were assessed by a linear mixed effects model with a random effect on the intercept, and adjustment for baseline values. The primary outcome was health-related quality of life (HRQoL); secondary outcomes were mood state, dyspnea, gas exchange, functional status, pulmonary function, and exacerbation frequency.

Results

Although the addition of NIPPV did not significantly improve the Chronic Respiratory Questionnaire compared to rehabilitation alone (mean difference in change between groups -1.3 points (95% CI: -9.7 to 7.4)), the addition of NIPPV did improve HRQoL assessed with the Maugeri Respiratory Failure questionnaire (-13.4% (-22.7 to -4.2; p = 0.005)), mood state (Hospital Anxiety and Depression scale -4.0 points (-7.8 to 0.0; p = 0.05)), dyspnea (Medical Research Council -0.4 points (-0.8 to -0.0; p = 0.05)), daytime arterial blood gases (PaCO₂ -0.4 kPa (-0.8 to -0.2; p = 0.01); PaO₂ 0.8 kPa (0.0 to 1.5; p = 0.03)), 6-minute walking distance (77.3 m (46.4 to 108.0; p < 0.001)), Groningen Activity and Restriction scale (-3.8 points (-7.4 to -0.4; p = 0.03)), and forced expiratory volume in 1 second (115 ml (19 to 211; p = 0.019)). Exacerbation frequency was not changed.

Conclusions

The addition of NIPPV to pulmonary rehabilitation for 2 years in severe COPD patients with chronic hypercapnic respiratory failure improves HRQoL, mood, dyspnea, gas exchange, exercise tolerance and lung function decline. The benefits increase further with time.

Trial registration

ClinicalTrials.Gov (ID NCT00135538).     

Potential for strength and endurance training to amplify endurance performance

The impact of adding heavy-resistance training to increase leg-muscle strength was studied in eight cycling- and running-trained subjects who were already at a steady-state level of performance. Strength training was performed 3 days/wk for 10 wk, whereas endurance training remained constant during this phase. After 10 wk, leg strength was increased by an average of 30%, but thigh girth and biopsied vastus lateralis muscle fiber areas (fast and slow twitch) and citrate synthase activities were unchanged. Maximal O2 uptake (VO2max) was also unchanged by heavy-resistance training during cycling (55 ml.kg-1.min-1) and treadmill running (60 ml.kg-1.min-1); however, short-term endurance (4-8 min) was increased by 11 and 13% (P less than 0.05) during cycling and running, respectively. Long-term cycling to exhaustion at 80% VO2max increased from 71 to 85 min (P less than 0.05) after the addition of strength training, whereas long-term running (10 km times) results were inconclusive. These data do not demonstrate any negative performance effects of adding heavy-resistance training to ongoing endurance-training regimens. They indicate that certain types of endurance performance, particularly those requiring fast-twitch fiber recruitment, can be improved by strength-training supplementation.     

Effects of complex training on explosive strength in adolescent male basketball players

The purpose of this study was to evaluate the effects of a complex training program, a combined practice of weight training and plyometrics, on explosive strength development of young basketball players. Twenty-five young male athletes, aged 14-15 years old, were assessed using squat jump (SJ), countermovement jump (CMJ), Abalakov test (ABA), depth jump (DJ), mechanical power (MP), and medicine ball throw (MBT), before and after a 10-week in-season training program. Both the control group (CG; n = 10) and the experimental group (EG; n = 15) kept up their regular sports practice; additionally, the EG performed 2 sessions per week of a complex training program. The EG significantly improved in the SJ, CMJ, ABA, and MBT values (p < 0.05). The CG significantly decreased the values (p < 0.05) of CMJ, ABA, and MP, while significantly increasing the MBT values (p < 0.05). Our results support the use of complex training to improve the upper and lower body explosivity levels in young basketball players. In conclusion, this study showed that more strength conditioning is needed during the sport practice season. Furthermore, we also conclude that complex training is a useful working tool for coaches, innovative in this strength-training domain, equally contributing to a better time-efficient training.     

The effects of resistance training on explosive strength indicators in adolescent basketball players

ABSTRACT: Santos, EJAM and Janeira, MAAS. The effects of resistance training on explosive strength indicators in adolescent basketball players. J Strength Cond Res 26(10): 2641-2647, 2012-The purpose of this study was to assess the effects of a lower- and upper-body 10-week in-season resistance training program on explosive strength development in young basketball players. Twenty-five adolescent male athletes, aged 14-15 years old, were randomly assigned to an experimental group (EG; n = 15) and a control group (CG; n = 10). The subjects were assessed at baseline and after training for squat jump (SJ), countermovement jump (CMJ), Abalakov test, drop jump, and seated medicine ball throw (MBT). The EG showed significant increases (p < 0.05) in all the variable scores. Conversely, the CG significantly decreased (p < 0.05) in SJ, CMJ, and Abalakov test scores and significantly increased in the results of MBT test (p < 0.05). The groups were similar on pretest, but significant differences (p < 0.05) occurred on posttest in all the variables. The results of this study show that a 10-week in-season resistance training program with moderate volume and intensity loads increased vertical jump and MBT performance in adolescent male basketball players. Coaches should know that such a short resistance training program specifically designed for young basketball players induce increased explosivity levels, which are essential to a better basketball performance, with no extra overload on adolescents' skeletal muscle development.     

Short-term training enhances endothelium-dependent dilation of coronary arteries, not arterioles.

Our objective was to test the hypothesis that short-term exercise training (STR) of pigs increases endothelium-dependent dilation (EDD) of coronary arteries but not coronary arterioles. Female Yucatan miniature swine ran on a treadmill for 1 h, at 3.5 mph, twice daily for 7 days (STR; n = 28). Skeletal muscle citrate synthase activity was increased in STR compared with sedentary controls (Sed; n = 26). Vasoreactivity was evaluated in isolated segments of conduit arteries (1-2 mm ID, 3-4 mm length) mounted on myographs and in arterioles (50-100 microm ID) isolated and cannulated with micropipettes with intraluminal pressure set at 60 cmH(2)O. EDD was assessed by examining responses to increasing concentrations of bradykinin (BK) (conduit arteries 10(-12)-10(-6) M and arterioles 10(-13)-10(-6) M). There were no differences in maximal EDD or BK sensitivity of coronary arterioles from Sed and STR hearts. In contrast, sensitivity of conduit arteries (precontracted with PGF(2alpha)) to BK was increased significantly (P < 0.05) in STR (EC(50), 2.33 +/- 0.62 nM, n = 12) compared with Sed animals (EC(50), 3.88 +/- 0.62 nM, n = 13). Immunoblot analysis revealed that coronary arteries from STR and Sed animals had similar levels of endothelial nitric oxide synthase (eNOS). In contrast, eNOS protein was increased in STR aortic endothelial cells. Neither protein nor mRNA levels of eNOS were different in coronary arterioles from STR compared with Sed animals. STR did not alter expression of superoxide dismutase (SOD-1) protein in any artery examined. We conclude that pigs exhibit increases in EDD of conduit arteries, but not in coronary arterioles, at the onset of exercise training. These adaptations in pigs do not appear to be mediated by alterations in eNOS or SOD-1 expression.     

Training and detraining effects of the resistance vs. endurance program on body composition, body size, and physical performance in young men

The purpose of this study was to investigate the changes in the body composition, body size, muscle strength, and VO2max after 24 weeks of resistance or endurance training and detraining in young men. Thirty healthy college-aged men (20.4 ± 1.36 years) participated in the study. Subjects were assigned to resistance training group (RTG, n = 10), endurance training group (ETG, n = 10), and control group (CG, n = 10). The training program consisted of running or weight-resistance exercise for 3 sessions per week under supervision. VO2max, upper and lower body strength (UBS, LBS), body fat, lean body mass, and body circumference were measured at baseline and after training and detraining. After the training period, the exercise groups demonstrated significant increases in VO2max and LBS (p < 0.05). The UBS, lean mass (LM), and body size of arm and calf were significantly greater in the RTG than in the other 2 groups (p<0.05). In addition, the strength and LM of the RTG were still greater than the baseline values after 24 weeks of detraining (p < 0.05). The conclusions of this study are (a) that endurance or resistance training alone led to training-specific improvements in physical performance, body composition, and body size of the arms for the young men examined and (b) that the RTG maintained the gains in strength and LM for more prolonged periods after training ceased than the endurance training group.     

Effects of whole-body vibration training on explosive strength and postural control in young female athletes

This study aimed to evaluate the effectiveness of a whole-body vibration training program to improve neuromuscular performance in young elite female athletes. Twenty-three women basketball players (14-18 years old) were randomly assigned to a control group (CG, n = 11) or to a whole-body vibration group (WBVG, n = 12). During the study period, both groups continued their usual training program, but the WBVG also underwent a 15-week vibration training program. We analyzed the countermovement jump test (CMJ), the 1-leg hop test for the right leg and for the left leg, and the single-limb standing balance for both legs and with eyes open and closed at 3 time points: before training (T1), after an 8-week training period (T2), and after a further 7-week training period (T3). Compared with the CG, CMJ increased significantly in the WBVG from T1 to T2 (6.47%, p < 0.001), T1 to T3 (10.07%, p = 0.005), and T2 to T3 (3.38%, p < 0.001). One-leg hop test for the right and left legs also showed significantly higher values in WBVG from T1 to T2 (10.12%, p < 0.001 and 9.63%, p = 0.002, respectively) and T1 to T3 (14.17%, p = 0.001 and 15.17%, p = 0.004, respectively). Lateral deviation of the center of pressure in the closed eyes test decreased significantly in WBVG for both right and left leg, from T1 to T2 (-22.20%, p = 0.043 and -34.77%, p < 0.001, respectively) and from T1 to T3 (-33.14%, p = 0.027 and -33.58%, p = 0.043, respectively) compared with the CG. In conclusion, our results show that a 15-week whole-body vibration training program improves explosive strength and postural stability in adolescent female basketball players.