Effect of repeated post-resistance exercise cold or hot water immersion on in-season inflammatory responses in academy rugby players: a randomised controlled cross-over design

Barry G Horgan; Nicholas P West; Nicolin Tee; Shona L Halson; Eric J Drinkwater; Dale W Chapman; G Gregory Haff

doi:10.1007/s00421-024-05424-3

Effect of repeated post-resistance exercise cold or hot water immersion on in-season inflammatory responses in academy rugby players: a randomised controlled cross-over design

Eur J Appl Physiol. 2024 Apr 13. doi: 10.1007/s00421-024-05424-3. Online ahead of print.

Authors

Barry G Horgan^{1

2

3}, Nicholas P West⁴, Nicolin Tee^{5

6}, Shona L Halson^{5

7}, Eric J Drinkwater^{8

9}, Dale W Chapman^{5

8

10}, G Gregory Haff^{8

11}

Affiliations

¹ Australian Institute of Sport (AIS), Australian Sports Commission, Bruce, ACT, 2617, Australia. barry.horgan2@gmail.com.
² School of Medical and Health Sciences, Edith Cowan University (ECU), Joondalup, WA, Australia. barry.horgan2@gmail.com.
³ Brumbies Rugby, Bruce, ACT, Australia. barry.horgan2@gmail.com.
⁴ School of Medical Science, Menzies Health Institute QLD, Griffith University, Gold coast, Queensland, Australia.
⁵ Australian Institute of Sport (AIS), Australian Sports Commission, Bruce, ACT, 2617, Australia.
⁶ Mary MacKillop Institute of Health Research, Australian Catholic University, Melbourne, VIC, Australia.
⁷ School of Behavioural and Health Sciences, Australian Catholic University, Banyo, Queensland, Australia.
⁸ School of Medical and Health Sciences, Edith Cowan University (ECU), Joondalup, WA, Australia.
⁹ Centre for Sport Research, School of Exercise & Nutrition Sciences, Deakin University, Geelong, VIC, Australia.
¹⁰ Curtin University, Bentley, WA, 6102, Australia.
¹¹ Directorate of Psychology and Sport, University of Salford, Greater Manchester, Salford, UK.

PMID: 38613679
DOI: 10.1007/s00421-024-05424-3

Abstract

Purpose: Uncertainty exists if post-resistance exercise hydrotherapy attenuates chronic inflammatory and hormone responses. The effects of repeated post-resistance exercise water immersion on inflammatory and hormone responses in athletes were investigated.

Methods: Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week programme divided into 3 $\times$ 4-week blocks of post-resistance exercise water immersion (either, no immersion control [CON]; cold [CWI]; or hot [HWI] water immersion), utilising a randomised cross-over pre-post design. Fasted, morning blood measures were collected prior to commencement of first intervention block, and every fourth week thereafter. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects.

Results: Repeated CWI (p = 0.025, g = 0.05) and HWI (p < 0.001, g = 0.62) reduced creatine kinase (CK), compared to CON. HWI decreased (p = 0.013, g = 0.59) interleukin (IL)-1ra, compared to CON. HWI increased (p < 0.001-0.026, g = 0.06-0.17) growth factors (PDGF-BB, IGF-1), compared to CON and CWI. CWI increased (p = 0.004, g = 0.46) heat shock protein-72 (HSP-72), compared to HWI.

Conclusion: Post-resistance exercise CWI or HWI resulted in trivial and moderate reductions in CK, respectively, which may be partly due to hydrostatic effects of water immersion. Post-resistance exercise HWI moderately decreased IL-1ra, which may be associated with post-resistance exercise skeletal muscle inflammation influencing chronic resistance exercise adaptive responses. Following post-resistance exercise water immersion, CWI increased HSP-72 suggesting a thermoregulatory response indicating improved adaptive inflammatory responses to temperature changes, while HWI increased growth factors (PDGF-BB, IGF-1) indicating different systematic signalling pathway activation. Our data supports the continued use of post-resistance exercise water immersion recovery strategies of any temperature during in-season competition phases for improved inflammatory adaptive responses in athletes.

Keywords: Hydrotherapy; Inflammation; Recovery; Strength training; Team sports.