Participation in the Ironman Triathlon has increased rapidly since its inception in 1978 (Lepers, R., 2008). The inherent cross-training in triathlon limits optimization of performance in a single discipline (Millet, G. P., et al. 2002). Swimming requires more specificity of training than running or cycling as it is more dependent upon technique (Millet, G. P., et al. 2002; Zamparo, et al., 2010). Though Toussaint (1990) showed a decrease of propelling efficiency between swimmers and triathletes; this study tested short distance triathletes and swimmers. While elite Ironman Triathletes swam the Hawaii Ironman 10% slower than elite Long Distance Swimmers swam the Waikiki Roughwater Challenge; comparisons should not be made on time race time alone (Lepers, R., 2008). Several authors have reported swimming economy, as quantified by energy cost (EC) of locomotion as the best performance determinant in terrestrial and aquatic environments (di Prampero, P.E., 1986; Capelli, P., et al. 1995; Zamparo, et al., 2005). Zamparo (2005) found EC increased and stroke mechanics decreased at the end of a long distance swim in elite Long Distance Swimmers. However, Long Distance Swimmers and Ironman Triathletes have not been compared, nor have Ironman Triathletes been evaluated, on the economy and mechanics of long distance swimming.
Purpose: To compare the economy and stroke mechanics; stroke frequency (SF) and stroke length (SL), of Long Distance Swimmers and Ironman Triathletes before and after an 1829-m swim.
Methods: 6 (4 female, 2 male) well-trained Long Distance Swimmers (S) and 8 (all male) well-trained Ironman Triathletes (T) were tested on 2 separate sessions; Baseline-Familiarization (BF) and Experiment (E). The BF included a body composition test, 365.8-m swim at competition pace to establish pacing during the E and familiarization to the E protocol. Subjects returned within 7 days for the E where they swam 3x365.8-m (PRE), 1x1829-m (LONG) and 3x365.8-m (POST) at paces reflective of Ironman or 3K open water competition pace. Economy was quantified by EC (kJ/m); the ratio of total energy expenditure (Et) to pace. Et was calculated from the summation of anaerobic and aerobic energy expenditure as measured by lactate and VO2, immediately and 60-sec after each swim (di Prampero, P.E., et al., 1976; Montpetit, R., et al., 1981; Costill, D.L. et al., 1985; Zamparo, et al., 2005). Immediately upon obtainment of 60-sec of breath by breath VO2 data, subjects resumed swimming until completion of the protocol. VO2 was determined by the back extrapolation method. SF and SL were determined from video analysis.
Results: S, compared with T, had significantly lower pace and energy cost in the PRE and POST swims (p<0.05). T, on the POST compared with the PRE swims, exhibited a significant decrease in stroke length.
Conclusion: Long Distance Swimmers, compared with Ironman Triathletes, are more economical at swimming and more capable of maintaining stroke mechanics at the end of a long swim.