Tracking swim training

The daily guidance that coaches provide to their swimmers is based on a mixture of objective and subjective information amidst a multitude of unknown factors. Providing more objective measures may facilitate the comprehension of swimming in a context where world records continue to be broken and performance density continues to increase (Ganzevles, et al., 2017; Peterson et al., 2005). Based on the heuristic model introduced by Truijens (2011) (Figure 1), we developed and validated a new multisensory device in cooperation with Lode BV (Groningen, The Netherlands) and 2M Engineering (Valkenswaard, The Netherlands) together with accompanying algorithms to assist coaches in tracking the training of swimmers. While using the device, we focused on measuring the lap time (LT), heart rate (HR) and stroke rate (SR) real-time in a synchronized and reliable manner. We introduced a novel variable in the world of competitive swimming research, namely the jerk cost (JC), and studied it extensively. Furthermore, we elucidated how coaches can utilize the model and the device for the design and guidance of their training plans. In Chapter 2 we focused on mechanical variables. Specifically, we examined the reliability and practical usefulness of tri-axial accelerometers for tracking LT, stroke count (SC) and SR in swimming. The results showed high reliability, with significantly smaller measurement errors than manual stopwatch timing by the coach. In addition, we addressed the secondary research question a) on the practical usefulness of tri-axial accelerometers, by showing how information about the variables of interest throughout the session could assist the coach in safeguarding training compliance. We delved deeper into the acceleration signal in Chapter 3 to answer the question: what additional information can be gleaned from the acceleration signal? We focused on the intra-cyclic velocity variations during swimming because these are indicators of propulsion. Specifically, we studied the intra-cyclic variations of the acceleration signal itself, and the third time derivative of position, the jerk, following pertinent research on smoother and more efficient movement on land. We showed that jerk cost (JC) can discriminate between levels of swimming performance, in this case between elite and non-elite swimmers, and may thus provide an additional measure of swimming technique. The measurement of HR throughout a training session was studied in Chapter 4. Specifically, we were interested in the use of HR as an early predictor of the course of the training sessions. Two options were studied, the exercise HR during and the HR recovery after (HRRec) a warmup at a standardized velocity. The study showed that not the HRRec, but the exercise HR was the best predictor of HR in the subsequent training session and can be used by coaches to make specific adjustments if necessary. Chapter 5 discussed the current situation regarding the measurement of the performance-determining variables of interest, i.e. with a stopwatch by the coach and swimmers counting HR based on the pulse in their wrist or neck. The case was made that this situation is undesirable in terms of reliability and leaves little time for the coach to foster the coach-athlete relationship. New technological developments can assist in the measurement of performance-determining variables. The downside of this is that an abundance of data becomes available for coaches, raising issues of data management and interpretation. We explained how swim coaches can utilize the heuristic model to design, measure, coach and evaluate a training session that was tracked with the device developed in this project.