Concurrent Validity of a Velocity Perception Scale to Monitor Back Squat Exercise Intensity in Young Skiers.

Execution velocity is among the main variables used to quantify resistance exercise intensity. The velocity at which a given load is displaced is one of the factors, which determine the training adaptations induced in the muscles. The purpose of this study was to assess the validity of the scale of perceived velocity (SPV) applied to the back squat. The study participants were 11 international level young elite skiers (8 men and 3 women) of mean age, height, weight, and estimated 1-repetition maximum/body weight ratio (1RMest/BW) 15.4 ± 1.12 years, 166.8 ± 8.83 cm, 63.6 ± 11.56 kg, and 1.61 ± 0.40, respectively. Participants performed a 2-stage protocol. In the first stage (familiarization), subjects were instructed on how to use the scale and performed an incremental load test to determine their 1RMest. In the second, or validation stage (72 hours later), exercises were executed at 6 relative intensities (20, 30, 40, 50, 60, and 70% of 1RMest) in random order in 2 sessions separated by 72 hours. Real velocity (Velreal) and perceived velocity (Velscale) values were linearly distributed showing excellent coefficients of determination (R(2) = 0.98 and R(2) = 0.99 for the 2-session trial). A 2-way repeated measures analysis of variance (scale [2] × session [2] × intensity [6]) revealed significant differences in the factor intensity and the interaction scale × intensity (no significant differences were detected in scale, session, scale × session, or scale × session × intensity). These data support the validity of SPV to monitor exercise intensity during lower-body strength training.

Effects of Variable Resistance Training on Maximal Strength: A Meta-Analysis.

Variable resistance training (VRT) methods improve the rate of force development, coordination between antagonist and synergist muscles, the recruitment of motor units, and reduce the drop in force produced in the sticking region. However, the beneficial effects of long-term VRT on maximal strength both in athletes and untrained individuals have been much disputed. The purpose of this study was to compare in a meta-analysis the effects of a long-term (≥7 weeks) VRT program using chains or elastic bands and a similar constant resistance program in both trained adults practicing different sports and untrained individuals. Intervention effect sizes were compared among investigations meeting our selection and inclusion criteria using a random-effects model. The published studies considered were those addressing VRT effects on the 1 repetition maximum. Seven studies involving 235 subjects fulfilled the selection and inclusion criteria. Variable resistance training led to a significantly greater mean strength gain (weighted mean difference: 5.03 kg; 95% confidence interval: 2.26-7.80 kg; Z = 3.55; p < 0.001) than the gain recorded in response to conventional weight training. Long-term VRT training using chains or elastic bands attached to the barbell emerged as an effective evidence-based method of improving maximal strength both in athletes with different sports backgrounds and untrained subjects.

Development and validity of a scale of perception of velocity in resistance exercise.

This aims of this study were twofold; 1) to development a new scale of perceived velocity in the bench press exercise and 2) to examine the scales concurrent validity. Twenty one physically active males with mean ±SD age, height and weights of: 27.5 ± 4.7 years, 1.77 ± 0.07 m, and 79.8 ± 10.3 kg respectively, took part in the study. The criterion variable used to test the validity of the new scale was the mean execution velocity (Velreal) of the bench press exercise. Three intensities (light loads [< 40% 1RM], medium loads [40% -70% 1RM] and heavy loads [> 70% 1RM]) were measured randomly during 5 days of testing. Perceived velocity (Velscale) was measured immediately after each exercise set using the new scale. A positive linear correlation (r range = 0.69 to 0.81) was found in all three intensities, analyzed individually, between the Velreal and Velscale. Pearson correlations showed a greater frequency of scale use resulted higher correlation values (range r = 0.88 to 0.96). This study provides evidence of the concurrent validity of a new scale of perceived velocity in the bench press exercise in trained adult males. These results suggest the exercise intensity of the bench press can be quantified quickly and effective using this new scale of perceived velocity, particularly when training for maximum power. Key PointsMeasurement of perception of velocity can complement other scales of perception such as the 15 category Borg scale or the OMNI-RES.The results obtained in this study show that there was a positive correlation between the perceived velocity measured by the scale and actual velocityRegular use of the new scale of perceived velocity in external resistance training provides athletes with continuous feedback of execution velocity in each repetition and set, especially with high power loads.

Ubiquinol Short-Term Supplementation Prior to Strenuous Exercise Improves Physical Performance and Diminishes Muscle Damage.

The benefits of physical exercise on health are diminished when it is non-planned, strenuous, or vigorous, which causes an increase in oxygen consumption and production of free radicals, particularly serious at the muscular level. Ubiquinol could help achieve an antioxidant, anti-inflammatory, and ergogenic effect. The aim of this study is to evaluate whether a supplementation of ubiquinol during a short period could have a positive effect on muscle aggression, physical performance, and fatigue perception in non-elite athletes after high intensity circuit weight training. One hundred healthy and well-trained men, (firemen of the Fire Department of Granada) were enrolled in a placebo-controlled, double-blinded, and randomized study, and separated into two groups: the placebo group (PG, n = 50); and the ubiquinol group (UG, n = 50), supplemented with an oral dose. Before and after the intervention, data related to the number of repetitions, muscle strength, and perceived exertion, as well as blood samples were collected. An increase was observed in the UG regarding average load and repetitions, revealing an improvement in muscle performance. Ubiquinol supplementation also reduced muscle damage markers, showing a protective effect on muscle fibers. Therefore, this study provides evidence that ubiquinol supplementation improves muscle performance and prevents muscle damage after strenuous exercise in a population of well-trained individuals who are not elite athletes.

A new physical performance classification system for elite handball players: cluster analysis.

The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16) performed a set of tests to determine: 10 m (ST10) and 20 m (ST20) sprint time, ball release velocity (BRv), countermovement jump (CMJ) height and squat jump (SJ) height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest), the load corresponding to maximum mean power (LoadMP), the mean propulsive phase power at LoadMP (PMPPMP) and the peak power at LoadMP (PPEAKMP). Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs.

Effects of Fatigue on Throwing Performance in Experienced Team Handball Players.

The purpose of this study was to investigate the effect of central and peripheral physiological fatigue on throwing accuracy and ball release velocity in team handball. Twenty male subjects (age 24.7 ± 3.9 yrs, body mass 88.5 ± 5.0 kg, body height 1.86 ± 0.05 m, training experience 12.7 ± 3.8 yrs) from one handball team participated in this study. The participants completed four sets of eight laps of a circuit that consisted of specific team handball drills/exercises, with decreasing recovery times between the laps in each set in order to induce physiological fatigue. Duration of the recovery intervals determined the description of the effort made in each set: "light" (80 s recovery between laps), "moderate" (40 s), "hard" (20 s) and "very hard" (10 s). A heart rate, concentration of lactate in blood and the rate of perceived exertion (RPE) were recorded. Ball velocity and accuracy were measured after each set and they both decreased during a fatigue protocol. However, accuracy only decreased significantly in the end of the protocol, while ball release was already affected after the first round of the protocol. The results substantiate the initial hypothesis and confirm that both throwing accuracy and ball release velocity decrease significantly as physiological fatigue increases. These variables began to decrease when the fatigue quantification values were high or very high. The findings can be used by coaches to develop training programs to teach players how to identify fatigue thresholds and combat the effects of fatigue through decision-making skills at critical game moments.

Predicting Power Output of Upper Body using the OMNI-RES Scale.

The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI-RES scale values of different loads of the bench press exercise. Sixty males (age 23.61 2.81 year; body height 176.29 6.73 cm; body mass 73.28 4.75 kg) voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM) in the bench press exercise. A linear regression analysis produced a strong correlation (r = -0.94) between rating of perceived exertion (RPE) and mean bar velocity (Velmean). The Pearson correlation analysis between real power output (PotReal) and estimated power (PotEst) showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI-RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone.

Effect of folic acid supplementation on homocysteine concentration and association with training in handball players.

BACKGROUND: Strenuous physical activity can alter the status of folic acid, a vitamin directly associated with homocysteine (Hcy); alterations in this nutrient are a risk factor for cardiovascular disease. Handball players are a population at risk for nutrient deficiency because of poor dietary habits. OBJECTIVE: The aims of this study were to evaluate nutritional status for macronutrients and folic acid in members of a high-performance handball team, and determine the effect of a nutritional intervention with folic acid supplementation and education. DESIGN: A total of 14 high-performance handball players were monitored by recording training time, training intensity (according to three levels of residual heart rate (RHR): <60%, 60%-80% and >80%), and subjective perceived exertion (RPE) during a 4-month training period. Nutritional, laboratory and physical activity variables were recorded at baseline (Week 0), after 2 months of dietary supplementation with 200 µg folic acid (50% of the recommended daily allowance) (Week 8) and after 2 months without supplementation (Week 16). We compared training load and analyzed changes in plasma concentrations of Hcy before and after the intervention. RESULTS: Bivariate analysis showed a significant negative correlation (P < 0.01) between Hcy and folic acid concentrations (r = -0.84) at Week 8, reflecting a significant change in Hcy concentration (P < 0.05) as a result of hyperhomocysteinemia following the accumulation of high training loads. At Week 16 we observed a significant negative correlation (P < 0.01) between Hcy concentration and training time with an RHR <60%, indicating that aerobic exercise avoided abrupt changes in Hcy and may thus reduce the risk of cardiovascular accidents in high-performance athletes. CONCLUSION: Integral monitoring and education are needed for practitioners of handball sports to record their folic acid status, a factor that directly affects Hcy metabolism. Folic acid supplementation may protect athletes against alterations that can lead to cardiovascular events related to exertion during competition.