ELABORATION AND APPLICATION OF FUNCTIONAL EVALUATION TECHNIQUES FOR RUGBY UNION

The development of an effective training process for a specific physical activity is based on the knowledge of the ideal performance model, which is derived from the scientific research. Previous sport-science studies on rugby mainly focused their attention: a) on the determination of physical and functional characteristics of specific rugby populations (males, international competitive level, southern hemisphere context). b) on the definition of exercise workload, investigating absolute (external) loads on matches and official competitions through the quantification of specific tasks by time-motion analysis or using GPS tracking devices or accelerometers. The restricted range of the investigated populations may limit comparisons of physical and functional results to data measured in different contexts (women players, south European region). Furthermore, knowledge on relative (internal) exercise intensity and workload and rugby specific training load is quite limited for the lack of studies on these topics. Aims of this project were: a) to extend the knowledge on structural and functional characteristics of rugby players, monitoring two populations, Elite male players of the southern European region and Elite woman players, that have been poorly studied before. b) to apply to rugby union the HR-recording method of quantifying intensity and workload that is widely used in other team sports, yet seldom in this context, and to investigate the possibility of determining workload of two types of training sessions (Team Session and Unit Training). c) to verify the applicability of the s-RPE method proposed by Foster to rugby, analyzing the relationship between HR-based and s-RPE-based indexes of training intensity and workload. Study 1. This descriptive study was aimed at providing normative data on anthropometric characteristics of elite senior male rugby players of the southern European region. Methods: In 123 male players from the National Italian rugby team body weight, stature and % body fat (plicometry) were measured between 2006 and 2009. Mean and SD were calculated for forwards (FW) and backs (BK) and for positional subgroups and compared by t test (p< 0.05). Results & Discussion: FW were significantly heavier (108±8 vs 91±6Kg), taller (190±7 vs 183±5cm), had a larger % body fat (16±4 vs 11±4%) and fat free mass (91±5 vs 80±6Kg) compared to BK. Significant differences were found among FW subgroups, nor among BK subgrups. Conclusion: Our study provides a large normative database for elite male rugby union players in the southern European region. Furthermore, it confirms previous data on elite senior players of the southern hemisphere and role differences between FW and BK and between FW subgroups. Study 2. This study was aimed to provide up to date normative data on selected physiological and anthropometric characteristics of elite women players of the northern hemisphere. A selection of 22 players of the Italian national team underwent anthropometry, measurement of VO2max and lower extremities strength by vertical jumping test. Mean and SD were calculated in FW and BK and in positional subgroups (i.e. front row FW: props, locks; back row FW: flankers, n.8, hooker; inside BK: fly-half, centre; outside BK: wings, full back). Data were compared by t test. Statistical significance was set at p< 0.05. The athletes were 24±4 years old with a 9±6 years playing experience. FW were significantly taller, heavier, had a larger fat free mass, absolute VO2max and squat jump ability compared to BK. Front row FW were significantly taller, heavier, fatter and had a larger fat free mass compared to back row FW. No differences were detected in either anthropometric or functional parameters within BK positional subgroups. This study provides normative functional and anthropometric data for elite female rugby union players, with special reference to positional role. In agreement with male data, role differences in the majority of the measured parameters appear between FW and BK and between FW subgroups, while no difference was measured within BK subgroups. Study 3. The determination of training load can be particularly challenging in rugby. Our study aimed at applying a HR-based approach to measure absolute and relative workloads in two typologies of training session, typically used in rugby union: team session (TS) and unit training (UT). Methods: 8 FW and 7 BK undertook an incremental test to exhaustion on the treadmill to determine individual VO2max, HR at max and HR/VO2 relationship. Furthermore, HR was continuously monitored during 6 TS and 6 UT. For each training session, we determined absolute (Kcal·Kg-1· min-1) and relative intensity (%HRmax) and a cumulative index of workload (Lucia’s TRIMP). Mean and SD were calculated in FW and BK for TS and UT sessions and compared by t test (p<0,05). Results: The athletes were 24±3 years old and a VO2max of 47±5 ml·kg-1· min-1. FW and BK weight and height were: 108±8 and 92±12Kg; 187±1 and 181±1cm respectively. Training sessions had similar duration (55±15 min). TS were conducted at a higher relative intensity and caused a higher energy expenditure compared to UT in both FW and BK. Accordingly, TS had a higher training-load (i.e. TRIMP) compared to UT. Furthermore in UT sessions BK reached a significantly lower level of absolute and relative intensity compared to FW. Discussion: Our study successfully determined absolute and relative workload during specific training sessions in rugby union players. In this group the overall workload of both TS and UT was within the moderate intensity domain. Study 4. The aim of this study was to verify the applicability of the session-RPE method proposed by Foster to the specific contest of rugby, analyzing the relationship between HR-based and s-RPE-based indexes of training intensity and workload. Methods: 25 professional rugby players, 12 FW (mean±SD: age 28,8±6,5yr, stature 1,87±0,05m, body mass 106,1±11,2kg, body fat 20,0±5,0%) and 12 BK (mean±SD: age 27,1±5,8yr, stature 1,82±0,05m, body mass 89,8±9,3kg, body fat 14,2±5,8%) were involved in the study. Objective (mean HR, %HRmax) and subjective (s-RPE) indexes of intensity were recorded in 9 specific training sessions. Objective index of workload was settled as proposed by Edwards, through the identification of five zones of increasing intensity (SHRZ). TL was calculated by multiplying s-RPE for the duration of the session. Pearson correlations were performed to assess the relationship between %HRmax and s-RPE, between s-RPE and duration, and between SHRZ and TL. Furthermore multiple linear regressions were calculated to investigate the influence of duration, %HRmax and time spent in the different heart rate zones on the s-RPE parameter. Statistical significance was set at p<0,05. Results: Average training intensity was moderate (mean±SD: %HRmax 66±4%, s-RPE 4,3±0,7Au). Correlations, considering, respectively, all the individual data and session team-averages were: %HRmax/s-RPE: r=0,41, r=0,80; s-RPE/duration: r=0,47, r=0,94; SHRZ/TL: r=0,55, r=0,92. All these correlations were significant. The applied multiple linear regressions described significant influence of duration and time in the lowest (Z1) and in the highest HR intensity zones (Z4, Z5). Discussion: Subjective and objective indexes of exercise intensity and training load are highly correlated and therefore interchangeable when team average data are considered. On the contrary, interchangeability between these indexes is not sufficiently reliable to allow avoidance of the monitoring of objective parameters in individual subjects. Furthermore, our study suggests a possible independent effect of duration on the perception of effort during typical and specific rugby union training sessions. More research is needed to clear if duration may be an integrated component of s-RPE and may independently predict training load and overtraining in team sports.