Yo-Yo IR2 test and margaria test: validity, reliability and maximum heart rate in young soccer players

Yo-Yo Ir2 Test and Margaria Test: Validity, Reliability and Maximum Heart Rate in Young Soccer Players Cristiano Diniz da Silva1 Antônio José Natali2 Jorge Roberto Perrout de Lima3 Maurício Gattás Bara Filho3 Emerson Silami Garcia4 João Carlos Bouzas Marins5 1. Master's degree post-Graduation Program in Physical Education of the federal University of ViçosaFederal University of Juiz de Fora, Human Performance Laboratory of UFV (LAPEH) – Viçosa, MG, Brazil. CAPES scholarship recipient. 2. Physical Education Department of the Federal University of Viçosa – Viçosa, MG, Brazil. 3. Physical Education College of the Federal University of Juiz de Fora – Juiz de Fora, MG, Brazil. 4. Physical Education, Physiotherapy and Ocupational Therapy School of the Federla University of Minas Gerais – Belo Horizonte, MG, Brazil. 5. Physical Education Department of the Federal University of Viçosa. Human Performance Laboratory of UFV (LAPEH) – Viçosa, MG, Brazil. Mailing address: Rua Márcio Araújo, 174 apto. 01, bairro JK – 36570-000 – Viçosa, MG, Brazil. E-mail: 344 EXERCISE AND SPORTS SCIENCES Original Article Abstract The aims of the present study were: i) to evaluate the construct validity of Yo-Yo Intermittent Recovery Test Level 2 (Yo-Yo IR2) and of the Margaria Test (MT) with performance in high intensity exercise during official match play in soccer players; ii) to verify the reliability (test-retest) of the two tests; iii) to compare the values of the maximal individual heart rate (MHR) obtained in those protocols and match play Eighteen soccer players (mean ± SD; age 14 ± 0.8 years, height 172 ± 9 cm, weight 64.3 ± 8.5 kg) belonging to the same team were assessed in test-retest referred protocols and in the percentage of time spent above 85% of MHR (PRT >85%MHR) in two official match play of the U-15 Championship. High correlation was found between performance in the Yo-Yo IR2 and PRT >85%MHR (rs=0.71; p<0.05). There was not correlation between performance in MT and PRT >85%MHR (rs=0.44; p=0.06). The Yo-Yo IR2 was more variable and less reproducible (CV= 11%; CCI [95% IC]=0.38) than MT (CV= 1%; CCI [95% IC]=0.93). The highest value of MHR (p<0.001) occurred in the match play (202 ± 8 beats.min-1). MHR in Yo-Yo IR2 (194 ± 4 beats.min-1) was lower (p<0,006) than MT (197 ± 6 beats.min-1). In conclusion, the Yo-Yo IR2 can be considered more valid to predict maintenance of high exercise intensity during a match, which is an important performance measure in soccer. However, there is need of strict standardization among the evaluation procedures for stability of the measure. MHR should be observed in several situations, mainly competitive, so that the highest individual value can be reached. Keywords: soccer, exercise intensity, performance, heart rate, field test. INTRODUCTION The aerobic capacity evaluation of athletes is useful for the selection, for programs of physical fitness devising and for prediction and monitoring of physical performance in competitions(1). In the literature, there are many methods described for evaluation of aerobic capacity of soccer players(1). In laboratory, direct measurement of the maximum oxygen consumption ( O2max) in exhaustion test on treadmill(2,3) is considered the gold standard since it allows simultaneous evaluations of other important parameters such as threshold of metabolic transition, running economy and cardiac work. This procedure, despite its controversies(4,5), is considered to be valid for soccer, since significant correlation of the O2max with the final classification of the team in the competition(6) and with some performance variables in the match such as: completed distance(6-9), number of performed sprints(6-8), time of activities at high intensity(7,9,10) and number of interactions with the ball by the player has been found(7). However, an important limitation of this evaluation, especially for team sports, is that the procedures are time-consuming, require trained staff and costly equipment(11,12). Among the field tests, the Margaria test(13) (MT) has been highlighted in the evaluation of soccer players since it allows adjustments in the distance of the used dislocation, which should be completed in the shortest time possible and with constant velocity for estimation of the O2max. Thus, in only one procedure, it is possible to estimate performance by the equations of the 2,400m Copper test(14) or the Weltman test(15). Another advantage of this procedure is the easy place adaptability and the need of minimal equipment. However, the validity of these tests to soccer can be questioned since they do not reflect the physiological response of the match(3,16) for having straight and continuous movement characteristic and hence do not simulate the competitive load in which the players are demanded in many sudden changes of movement and direction(10,17-19). The Yo-Yo Intermittent Recovery Test Level 2 (Yo-Yo IR2) was proposed as a field test of easy applicability and low cost,(16,20). Using back and forth running (20m) with velocity increment of dislocation controlled by a sound sign, its main measurement characteristic is the action intermittence, characterized by recovery interval of 10 seconds between stimuli for new dislocation. The dislocations are carried out until player’s exhaustion, which is characterized when the sound signs are not followed anymore in the respective marks. Due to this characteristic, the Yo-Yo IR2 has been recommended as an optimum evaluation measurement for soccer(5,16). The performance Rev Bras Med Esporte – Vol. 17, No 5 – Set/Out, 2011 obtained in the Yo-Yo IR2 test has demonstrated significant correlation with fatigue time in a progressive running test on treadmill, with O2max and strong correlation with maximum dislocation distance completed in five minutes during a match in adult elite players(20). Another indication for its application is the possibility to observe the maximum heart rate (MHR) of the player during its performance, not presenting difference from the values observed in the exhaustion test procedures carried out on treadmill(16,20). The information of this variable is an important factor for relativization of load intensities in the training prescription. Although previous studies such as the previously reported have demonstrated the advantages of the Yo-Yo IR2 for soccer, as far as we are concerned, there is a shortage in studies with young players which try to detect the validity of the construct(21), reliability and suitability of this measurement for the observation of the MHR or even comparison of these aspects with other field assessment procedure. Another issue is the comparison of continuous field protocols with intermittent ones, since both stimuli can be used to facilitate the physiological adaptations and improve performance of soccer players(7,9). The construct validity and reliability are important factors to be considered by the technical staff at the time of protoc (...truncated)