The use of heart rate variability in assessing precompetitive stress in high-standard judo athletes

The objective of this study is to examine the sensitivity to and changes in heart rate variability (HRV) in stressful situations before judo competitions and to observe the differences among judo athletes according to their competitive standards in both official and unofficial competitions. 24 (10 male and 14 female) national- and international-standard athletes were evaluated. Each participant answered the Revised Competitive State Anxiety Inventory (CSAI-2R) and their HRV was recorded both during an official and unofficial competition. The MANOVA showed significant main effects of the athlete's standard and the type of competition in CSAI-2R, in HRV time domain, in HRV frequency domain and in HRV nonlinear analysis (p<0.05). International-standard judo athletes have lower somatic anxiety, cognitive anxiety, heart rate and low-high frequency ratio than national-standard athletes (p<0.05). International-standard athletes have a higher confidence, mean RR interval, standard deviation of RR, square root of the mean squared difference of successive RR intervals, number of consecutive RR that differ by more than 5 ms, short-term variability, long-term variability, long-range scaling exponents and short-range scaling exponent than national-standard judo athletes. In conclusion, international-standard athletes show less pre-competitive anxiety than the national-standard athletes and HRV analysis is sensitive to changes in pre-competitive anxiety.

A comparative study between serve mode and speed and its effectiveness in a high-level volleyball tournament

AIM

This study carries out a comparative analysis between serve mode and speed and its effectiveness at the 2004 Men's Olympic Qualification Tournament.

METHODS

A total of 377 serves were analysed, 124 of which belonged to Cuba vs Holland, 63 to Spain vs Cameroon, 100 to Spain vs Cuba, and 91 to Holland vs Cameroon. Serve were recorded using a tripod mounted radar gun.

RESULTS

The analysis has shown the predominance of jump serve (JUMP, 84.9%) compared with float serve with jump (FLOAT JUMP, 5.6%) and float serve (FLOAT, 9.5%). Only 25.3% of the total jump serves analysed was successfully stricken back making the first tempo attack possible. The respective percentages for FLOAT JUMP and FLOAT were 42.9% and 55.6%. Ball speed in JUMP (23.03+/-3.94 m.s(-1)) was markedly higher compared with FLOAT JUMP and FLOAT (12.05+/-3.44 m.s(-1) and 11.47+/-4.22 m.s(-1)). While negative outcomes (66.7%) in FLOAT stand out, a better balance between negative and positive outcomes were found in both JUMP (50%) and FLOAT JUMP (42.9%). However, no relationship was found between serve speed and its effectiveness outcome (R2=0 in the overall sample and R2=0.005, when pooling the five serve effectiveness categories into negative and positive outcomes. In fact, JUMP was mainly performed in the span of velocities between 23.06 and 28.06 m.s(-1) in both error and direct point categories.

CONCLUSION

We found no significant relationship between serve velocity and a better outcome related to effectiveness. In addition, JUMP and FLOAT JUMP present a better balance between negative and positive outcomes compared with FLOAT.