Wednesday, January 21, 2009

Research Update: Effect of Cold Water Immersion on Post-exercise Parasympathetic Reactivation

New sports Science Blog Added

I found a new blog entitled "Sports & Fitness Science: Blog on Sports Science and Fitness Science. Edited by Dr. Marco Cardinale, PhD"

I added it to my blog list on the right. Great stuff there.

New "Cool" Study
New study below on cold water immersion and its effects.

Some background first. Remember that the body uses sympathetic and parasympathetic stimulation. Think of sympathetic as the accelerator (increases heart rate (HR) among other effects) and parasympathetic as the brake (slows down HR).

The body likes to have a balance of parasympathetic and sympathetic at all times. Acute exercise (in general) increases sympathetic stimulation. A proposed way to faster recovery (ability to do more work with a shorter period of rest) is to increase parasympathetic, the "rest and digest" component of the nervous system.

Heart Rate Variability (HRV) is a way to look at the balance of sympathetic and parasympathetic stimulation.

Below is a study that looked at the effects of cold water immersion to see if it does just that. According to the study, the answer is yes if you are a male cyclist exercising at a pretty high intensity.

Special thanks to Cal Dietz at the U of MN (be sure to check out XL Athlete) and Jamie Carruthers Wakefield, UK for the following study.

Effect of cold water immersion on post-exercise parasympathetic

Am J Physiol Heart Circ Physiol. 2008 Dec 12. [Epub ahead of print]

Buchheit M, Peiffer JJ, Abbiss CR, Laursen PB.

The aim of the present study was to assess the effect of cold water
immersion (CWI) on post-exercise parasympathetic reactivation. Ten male
cyclists (age: 29 +/- 6 y) performed two repeated supramaximal cycling
exercises (SE1 and SE2) interspersed with a 20-min passive recovery
period, during which they were randomly assigned to either 5 min of CWI
in 14 degrees C, or a control condition (N) where they sat in an
environmental chamber (35.0 +/- 0.3 degrees C and 40.0 +/- 3.0%
relative humidity). Rectal temperature (Tre) and beat-to-beat heart
rate (HR) were recorded continuously. The time constant of HR recovery
(HRRtau) and a time varying vagal-related HR variability (HRV) index
(rMSSD30s) were assessed during the 6-min period immediately following

Resting vagal-related HRV indices were calculated during 3-min periods
2 min before and 3 min after SE1 and SE2. Results showed no effect of
CWI on Tre (P=0.29), SE performance (P=0.76) and HRRtau (P=0.61). In
contrast, all vagal-related HRV indices were decreased after SE1
(P<0.001), and tended to decrease even further after SE2 under N
condition; but not with CWI. Compared to the N condition, CWI increased
HRV indices before (P<0.05) and rMSSD30s after (P<0.05) SE2.

Our study shows that CWI can significantly restore the impaired vagal- related HRV indices observed after supramaximal exercise. CWI may serve
as a simple and effective means to accelerate parasympathetic
reactivation during the immediate period following supramaximal

My Notes Again: While I have not done an exhaustive search on this topic in some time, I am not currently sold on cold water immersion for recovery purposes. This study is very interesting, but other data is conflicting. In the end, try it out and be sure to test your results to assess the effectiveness of it.