Competitive surfing generally involves grouping 2–4 surfers in each competitive heat, which generally lasts 20–30 minutes, dependent on the format of the competition, and surf conditions. Competitive success is determined by subjective judging criteria, which examine the athlete's ability to ride the best waves, performing complex maneuvers under control. In other words, surfers' success is judged by their ability to obtain and ride the best waves during a competition, and ride them better than their opposition. Like any tournament style competition, the successful surfers from each round of competitive heats progress through the competition until the quarter, semi, and final rounds are completed and placing is determined.
Surfing (wave-riding) competition takes places in a variety of conditions that have a large effect on activity patterns such as the duration of wave riding and time spent paddling (5,7,8). The type of wave break and changing conditions such as wind, swell, and tide conditions greatly influence the nature of the surfing activity. However, analysis of both competitive and recreational surfing suggests that surfing can be characterized as a sport requiring multiple short-duration intermittent paddle efforts (5,7). In a competition, wave riding duration was found to be only 3.8% of total time, with paddling accounting for 51.4% of time, and no activity (i.e., stationary sitting on board) representing 42.5% of total time (miscellaneous activities 2.2%) (7). Although the mean paddling bout in a surfing competition was found to be approximately 30 seconds, and some paddling bouts are considerably extensive (i.e., lasing several minutes), the majority (∼60%) of these paddling bouts were only 1–20 seconds (∼25%, <10 seconds, ∼35% 10–20 seconds), highlighting the relative importance of shorter bouts of intense paddling (6,7).
Previous examinations have determined that neither oxygen uptake nor endurance paddling measures are valid in discriminating between competitive and recreational surfers but that short-duration paddling power may be a valid discriminator (3). Sprint paddling is likely an important aspect of surf competition, to catch waves and to gain a position advantage over their competitors during a heat. In addition, sprint paddling can be a key feature to ensure fast entry speed into waves, which will optimize position on the wave face, enhancing the opportunity for the execution of maneuvers that will maximize the judges' score (3,6,9). As such, sprint paddling ability is considered to be a significant factor in determining the competitive outcome.
No studies have examined the potential relationship between anthropometric and trainable physical factors such as strength, with sprint paddling performance. Considering the role of upper-body power in swimming (2), it stands to reason that strength of the upper-body and trunk could play a key role in enhancing sprint paddle performance. This information would be useful in guiding coaching decisions and in providing a basis of rationale for strength training in surfers. This study aimed to evaluate the association with anthropometry and upper-body pulling (pronated pull-up) strength with sprint kinematics of competitive surfers.
Experimental Approach to the Problem
To assess the association between anthropometric and strength qualities with sprint paddle performance, this study employed a correlation analysis within a group of adult male competitive surfers, and a comparison of anthropometric and strength qualities when athletes were grouped based on their sprint paddling velocity (faster and slower).
Ten competitive male surfers (23.9 ± 6.8 years, 177.0 ± 6.5 cm, 72.2 ± 2.4 kg) participated in this study. At the time of the study, the subjects were actively (in season) competing in, as a minimum standard, domestic ‘open’ competition, with the majority of the subjects having competed at International Surfing Association World Junior Championships and or professionals competing in the Association of Surfing Professionals World Qualifying Series events.
All the subjects received a clear explanation of the study, including the risks and benefits of participation and if following this explanation their decision was to not be included in the analysis it did not adversely affect any current or future competitive or team opportunities. All included subjects provided written informed consent for testing and data analysis. Approval for this investigation was granted from the Institutional Human Ethics Committee, and the study conformed to the Declaration of Helsinki for medical research involving human subjects.
The subject group was divided into 2 equal groups. One group performed their sprint-paddle testing, whereas the other group undertook the anthropometry and strength assessment. At the conclusion of this and after a 10-minute recovery, the groups were then alternated so that all testing could be completed for all the subjects.
All the subjects were assessed for height, mass, arm span, and the sum of 7 skinfolds. The sum of 7 skinfolds was determined after the measurement of the triceps, sub scapulae, biceps, supraspinale, abdominal, quadriceps, and calf skinfold using a Harpenden skinfold calliper (British Indicator, United Kingdom). A composite ratio of body mass divided by the sum of 7 skinfolds was then determined to reflect the amount of mass that is made up of lean tissue, termed the lean mass ratio (LMR). All the tests were conducted by a single researcher certified by the International Society for the Advancement of Kinanthropometry. The percentage typical error (%TE) for stature, mass, and standing reach, were 1.5, 1.2, and 2.0%, respectively, whereas the %TE for the skinfold assessment was 2.2%.
Sprint paddle testing was conducted in an outdoor 50-m swimming pool. This allowed for easy outline of distances for the subjects, control for the potential effect of tides, and currents experienced in most local waterways and provided for professional supervision by lifeguards and elimination of potential dangers from marine creatures.
The subjects performed a progressive warm-up of 200 m of low-intensity paddling, followed by a specific sprint paddling warm-up of 4 × 15-m sprint paddling efforts at 60, 70, 80, and 90% volitional effort in approximately 2-minute time intervals. After a 3- to 4-minute rest, the subjects performed 2 maximal effort sprint paddling time trials (i.e., 2 × 15 m) to determine maximum sprint paddling performance. The sprint paddle efforts were initiated from a stationary, prone lying position.
Using a purpose-built horizontal position transducer (I-REX, Southport, Australia) attached to the rear waist line of each subject's shorts, kinematic data were obtained and stored for analysis on a personal computer. The position transducer records a time stamp for each 0.02 m of displacement, thereby allowing for determination of sprint time from the start to 5, 10, and 15 m and by differentiation to determine peak sprint paddle velocity (4). The %TE for 5, 10, 15 m, and peak velocities were 4.4, 2.6, 2.1, and 2.2%, respectively
The subjects were assessed on their 1 repetition maximum (1RM) for the Pronated Pull-Up. Before the strength testing, the subjects performed 3 sets of a 30-second medicine ball circuit emphasizing upper-body and trunk activity, with 1 minute of rest between each medicine ball set. Four to 5 submaximal preparatory sets (2–4 reps), separated by 2–3 minutes of rest, were used to graduate the subjects' resistance load before the 1RM trials. The subjects were lifted to the final (i.e., upper) position with arms flexed fully at the elbow and the elbows in line with the scapulae such that the arms were flexed at the shoulder and scapulae adducted. The subjects then performed the initial eccentric action to a complete ‘hang’ position, then the concentric action to return to the start position. Additional load (in 2.5-kg increments) was added by suspending certified plate weights from a standard lifting belt worn around the waist. Between 1RM trials 2–3 minutes of rest was provided until a failed lift occurred, at this time the successful weight lifted in the previous lift was recorded as the subject's 1RM.
Pearson correlation and stepwise multiple linear regression analysis was applied to determine the individual and group associations between each of the primary variables to the outcome variables of peak paddling velocity, and time at 5, 10, and 15 m. In addition the group was divided into half, based on the median of the time to 15 m, with anthropometry and strength characteristics assessed between these groups using independent t-tests, and Cohen's effect size (d) applied to reflect the magnitude of any differences. For all the tests, minimum significance was considered to be achieved when p ≤ 0.05.
Of the anthropometry measures, only arm span was found to have a significant (p < 0.05) correlation with the sprint paddle performances to 5 and 10 m (r = 0.77 and 0.67, respectively). Maximal pull-up strength was found to be moderately associated with time to 5-m (r = 0.69), 10-m (r = 0.61), and 15-m time (r = 0.51) (p < 0.05). Strong associations were found between relative (total kilograms lifted per athlete mass) upper-body pulling strength and sprint paddling time to 5, 10, and 15 m (Figure 1, r = 0.94, 0.93, 0.88, respectively) and peak sprint paddling velocity (Figure 2, r = 0.66). Stepwise linear regression did not elucidate any stronger associations between primary and outcome variables. Although no differences were found in anthropometric measures between groups of faster and slower sprint paddlers, relative upper-body pulling strength was found to be superior (p < 0.05) in the faster group, with large effect (Table 1, d = 1.88).
The purpose of this study was to evaluate the potential association between anthropometry and upper-body pulling (pronated pull-up) strength with sprint paddle kinematics of competitive surfers. This investigation seemed worthwhile, because although sprint paddling performance is believed to be worthwhile in surfers, strength training in elite surfers is not highly adopted, nor is there an evidence base to support its use. The results of this study are novel, because they demonstrate a very strong association between relative upper-body pulling strength and sprint paddling performance in surfers.
We did not find a strong association between lower skinfold thickness or with the LMR and sprint paddling ability. However, this must be considered in the context of this study, where we did not have a large range of skinfold thicknesses, LMR, nor did we have a very large number of subjects, all of which could reduce the likelihood of finding an association between these measures and sprint paddling performance. In addition, it must be considered that although maximal pull-up strength was found to be moderately associated with time to 5-m (r = 0.69), 10-m (r = 0.61), and 15-m time (r = 0.51), pull-up strength relative to body mass (total kilograms lifted per athlete mass) resulted in the strongest associations observed (Figure 1). Furthermore, maximal pull-up strength was not different between the faster and slower sprint paddling groups, yet this figure relative to body mass (maximum relative pull-up strength) was significantly (p < 0.05) higher for the faster group, with a large magnitude of difference (d = 1.88). This result suggests that surfers require highly developed upper-body pulling strength, but this must be accompanied by low-fat mass to optimize their relative upper-body strength score.
It stands to reason that the strongest association between relative pull-up strength is with time to 5 and 10 m (r = 0.93), and the strength of this association declines as distance increases (15 m: r = 0.88), and with peak sprint paddling velocity (r = 0.66). As with any start to a movement (1), the surfer must overcome a higher resistance initially to accelerate themselves on the surfboard. As such, it is logical that time from stationary to 5 and 10 m, distances that are dominated by acceleration to top speed (4), are more highly associated with upper-body strength, and that with longer distances and at peak velocity, the influence of maximum strength would be reduced.
This analysis has not demonstrated cause and effect between increased pull-up strength and improving sprint paddling ability. Further research efforts in this area should examine the chronic application of a strength training program, and variations within (i.e., closed vs. open kinetic chain) for the upper-body, and its influence on sprint paddle performance in surfers.
Coaches and sport scientists working with competitive surfers should implement strength training with their athletes, including an emphasis on developing high relative upper-body strength to compliment training in other areas (sensorimotor, mobility, endurance, etc.). Competitive surfers perform a great deal of paddling in their structured and unstructured training sessions, therefore adding a structured strength training program (including upper-body strength training, rotator cuff strengthening, etc.) may greatly compliment the overall training of competitive surfers.