Training load quantification in elite swimmers using a modified version of the training impulse method

Abstract

Prior reports have described the limitations of quantifying internal training loads using hear rate (HR)-based objective methods such as the training impulse (TRIMP) method, especially when high-intensity interval exercises are performed. A weakness of the TRIMP method is that it does not discriminate between exercise and rest periods, expressing both states into a single mean intensity value that could lead to an underestimate of training loads. This study was designed to compare Banister's original TRIMP method (1991) and a modified calculation procedure (TRIMPc) based on the cumulative sum of partial TRIMP, and to determine how each model relates to the session rating of perceived exertion (s-RPE), a HR-independent training load indicator. Over four weeks, 17 elite swimmers completed 328 pool training sessions. Mean HR for the full duration of a session and partial values for each 50 m of swimming distance and rest period were recorded to calculate the classic TRIMP and the proposed variant (TRIMPc). The s-RPE questionnaire was self-administered 30 minutes after each training session. Both TRIMPc and TRIMP measures strongly correlated with s-RPE scores (r = 0.724 and 0.702, respectively; P < 0.001). However, TRIMPc was ∼9% higher on average than TRIMP (117 ± 53 vs. 107 ± 47; P < 0.001), with proportionally greater inter-method difference with increasing workload intensity. Therefore, TRIMPc appears to be a more accurate and appropriate procedure for quantifying training load, particularly when monitoring interval training sessions, since it allows weighting both exercise and recovery intervals separately for the corresponding HR-derived intensity.

Keywords:

• Interval training
• swimming
• s-RPE
• TRIMP
• heart rate

Acknowledgements

The authors thank the swimmers and coaches (Jordi Murio and Patrick Pearson) for their collaboration and commitment to this study. We also thank Chris Brammer who provided valuable feedback on drafts of this study.

Additional information

Funding

The data here presented are part of a larger study (ALTITUDE project) supported by grants awarded by the Ministry of Science and Innovation of Spain [Ministerio de Ciencia e Innovación, DEP2009-09181], the Higher Sports Council of Spain [Consejo Superior de Deportes 35/UPB/10, 005/UPB10/11, 112/UPB10/12, CAR-UGr 2009, CAR-UGr 2011], Dutch Olympic Committee [NOC*NSF WOT/44090101] and the National Institute of Physical Education of Catalonia Generalitat de Catalunya [Research Support Grants 2011, 2012]. A.G.R. was supported by a FPU grant from the Ministry of Economy and Innovation of Spain [FPU 12/0060].