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ournal of Science and Medicine in Sport (2007) 10, 467—470

HORT REPORT

ontrast water immersion hastens plasmaactate decrease after intensenaerobic exercise

. Hugh Morton ∗

nstitute of Food, Nutrition and Human Health, Massey University,rivate Bag 11-222, Palmerston North, New Zealand

eceived 10 November 2005; received in revised form 23 August 2006; accepted 14 September 2006

KEYWORDSCryotherapy;Hydrotherapy;Recovery;Thermotherapy

Summary The benefits of rapid recovery after intense exercise are widely recog-nised, and lactate elimination is one indicator of recovery rate. This study examinedthe effect of contrast (alternating hot and cold) water immersion (CWI) on the rateof plasma lactate decrease during recovery after intense anaerobic exercise. Elevensubjects on each of two occasions undertook four successive 30-s Wingate tests sep-arated by 30-s rest periods. On each occasion, plasma lactate concentration duringrecovery was measured 5 min post-exercise and thereafter at 5 min intervals for30 min. On one occasion (determined randomly), the subjects recovered passively(PR) on a recovery bed and, on the other, they alternated partial body immersionin hot (36 ◦C) and cold (12 ◦C) water baths. Plasma lactate concentrations wereanalysed by repeated measures analysis of variance and by fitting a linear regres-sion model, allowing for both gender and recovery mode differences. The rate ofdecrease in plasma lactate concentration over the 30-min recovery period was sig-nificantly higher (p < 0.001) in CWI; 0.28(±0.02) mmol L−1 min−1 (CWI) compared to0.22(±0.02) mmol L−1 min−1 (PR). These values do not differ significantly between

males and females. Contrast water immersion is a valid method of hastening plasmalactate decrease during recovery after intense anaerobic exercise for both malesand females. An approximately 1.8 mmol L−1 difference between the two conditionsmay be expected after 30 min. With differences among elite competitors as little as1—2%, this reduction may be of practical significance.© 2006 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

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∗ Tel.: +64 6 350 4265; fax: +64 6 350 5781.E-mail address: H.Morton@massey.ac.nz.

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440-2440/$ — see front matter © 2006 Sports Medicine Australia. Publisheoi:10.1016/j.jsams.2006.09.004

ntroduction

ecovery after strenuous exercise is an importantssue for athletes. Any sport that has one or a com-ination of intense acceleration, power, strength or

d by Elsevier Ltd. All rights reserved.

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speed repeatability is likely to benefit from strate-gies that accelerate the recovery process.1 Veryhigh intensity exercise places a particularly heavydemand on anaerobic glycolysis and muscle lactatelevels can increase significantly above resting val-ues, although levels in plasma are lower and lagbehind. Intramuscular accumulation of lactate andhydrogen ions have been associated with impairedforce production2 and, whatever mechanism(s) maybe at work, the removal of lactate may thereforebe beneficial.

One recovery technique being practiced byathletes, contrast (alternating hot and cold) waterimmersion (CWI), reportedly results in lighterand less tight muscles with a feeling of mentalfreshness.1 In a recent review of the technique,Cochrane discusses the mechanisms justifyingits merits and concludes that very few scientificstudies have focussed on the effectiveness ornature of CWI for post-exercise treatment.3 Suchmechanisms may be metabolically related,4 neuro-logically related,5 thermodynamically related6 ormassage related.7 A recent study by Coffey et al.found that CWI lowered post-exercise lactate andimproved the subjective perception of recovery,suggesting the technique shows promise.8 Thepresent study was therefore undertaken to assessthe nature of post-exercise lactate changes broughtabout by CWI compared to passive recovery (PR).

Materials and methods

Eleven subjects (6 male, 5 female; age 21.7 ± 1.1and 20.2 ± 0.8 years; height 1.63 ± 0.11 and1.78 ± 0.13 cm; mass 84.1 ± 5.2 and 70.5 ± 4.7 kg,respectively) participated in the study. All under-took moderate exercise 3—4 times per week butnot regular high intensity (anaerobic) activity. Allsigned informed consent in accordance with theUniversity Human Ethics Committee and the Dec-laration of Helsinki.

All subjects attended testing on three occa-sions. On the first, their age, mass and heightwere recorded and they performed familiarisationWingate trials on the ergocycle (Lifecycle, Life Fit-ness, USA). They also performed trial immersionsin the hot (36 ◦C) and cold (12 ◦C) water baths, andlay passively on the recovery bed adjacent to thebaths.

On each of the next two occasions, after a 5-minwarm-up at resistance level 2 (approximately 52 W)

and a brief inactive pause, all subjects performedfour successive 30-s Wingate tests (resistance lev-els ranged from 12—20, power range 203—362 W),separated by 30-s relative rest periods cycling at

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R.H. Morton

evel 2. Subjects were verbally encouraged to pro-uce all-out efforts in all tests. Subjects werenstructed to refrain from any moderate or stren-ous physical activity and from the ingestion of anyaffeine, for 24 h immediately preceding each ses-ion. After the first session, subjects were randomlyllocated to either passive recovery (PR) or CWI.fter the second session they undertook the otherecovery protocol. Sessions were separated by ateast seven days and took place in the early morn-ngs. Participants were instructed not to consumeood or liquid (apart from water) for 10 h prior toesting.

Passive recovery consisted of lying stationary onhe recovery bed for 30 min. CWI recovery consistedf alternating immersion of subjects’ lower bodyp to their gluteal fold in the hot and cold baths:ot (9), cold (1), hot (4), cold (1), hot (4), cold1), hot (4), cold (1), hot (4) and cold (1); time ininutes.Fingertip blood was sampled 5 min after the end

f the fourth Wingate test and thereafter at 5-minntervals for 30 min. Samples were drawn using aterile lancing device (Softclix Pro) following manu-acturer’s instructions. Twenty microlitre capillaryube samples were analysed immediately, using are-calibrated lactate analyser (YSI 1500, Yellowprings Inc., USA).

All data were subjected to a three-way repeatedeasures analysis of variance with interactions

Minitab Inc., State College, PA).For a short period following a peak occurring

bout 4—5 min post-exercise, the time (t) coursef blood lactate can be approximated by a simpleinear regression. This study addresses whether theegression slope is modulated by CWI (and maybelso by gender differences). This is achieved byncorporating dummy variables for both factors.9

o assess inter-subject differences and characterisehe effect of CWI on the nature of the lactate curveuring recovery in males and females, simple lin-ar regressions were fitted to individual subjectata for each trial and the 22 parameter estimatesnalysed by two-way repeated measures ANOVAMinitab Inc.). The significance level was set at 0.05hroughout.

esults

ean blood lactate concentrations evidence only aignificant time trend (p < 0.001) and its interaction

ith recovery mode (p < 0.001). Between subjectifferences are also evident (p < 0.05).

The fitted dummy variable regression modelncluding only significant (p < 0.01) parameters

Contrast water immersion

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Figure 1 Mean plasma lactate values over time.

standard errors) was:

a(t) = 14.61(±0.47) − 1.99(±0.38)y

− 0.22(±0.02)t − 0.06(±0.02)xt

ith adjusted R2 = 54.7%. Substituting for theppropriate dummy variables (y = 1 for females and= 1 for CWI) enables simple linear regressions to bestimated for each of the four gender/mode com-inations.

The adjusted goodness of fit is not high (54.7%),ost likely because of between-subject differ-

nces. Fitting simple linear regressions to the datarom each subject in each trial confirms this,nd that linearity is a good model for these data94.9% < R2 < 99.4%). Analysis of the intercepts andlopes indicates that slopes differ only betweenecovery modes, and intercepts differ only betweenales and females. Fig. 1, which plots the mean

alues for all gender/mode combinations, illus-rates these points graphically.

iscussion

he primary finding of this study was that CWIecovery not only resulted in lower blood lactate0 min post-exercise than with PR, but also morepecifically raised its rate of removal above that ofR. These rates were gender-independent. Thus,WI is a valid and effective means of hasteninglood lactate clearance during recovery from highntensity exercise in both males and females.

Blood lactate during active recovery fromigh intensity exercise is primarily removed viaxidation,3 and it remains to be established howWI may facilitate this process. Since CWI required

articipants to climb in and out of the water baths,t could be said that CWI involved some physicalctivity over and above the passive recovery con-ition. Since active recovery per se hastens lac-

469

ate clearance, this may be a confounding factorn explaining the primary finding. The design of thistudy does not permit a definitive answer to thisuestion, but it is noted that the level of physicalctivity defining active recovery in other studies2,8

s far higher than simply climbing in and out of theater baths a few times over a 30-min period. The

trength of the findings of this investigation shouldlso be interpreted in light of the following issues:ying supine in the passive recovery condition mayimit the muscle pump and hence lactate removal,nd the effects of hydrostatic pressure may con-ribute to the benefits of CWI.

We conclude that contrasting successive hot andold water immersion and its consequent effect onlood flow and/or temperature may be the likelyausal factor in increasing lactate removal rate buthat the precise mechanism of this phenomenonemains unclear. Further research is needed to com-are CWI with active recovery, and to establishhether a 1.8 mmol L−1 reduction is sufficient toenefit subsequent performance.

Practical implications

• Contrast water immersion is a valid and effec-tive means of accelerating recovery from highintensity exercise in both males and females.

• Contrast water immersion hastens blood lac-tate clearance, results in lighter and less tightmuscles with a feeling of mental freshness,and improves the subjective perception ofrecovery.

cknowledgements

he data-gathering contributions of Natalie Tongnd Pamela Meyer are gratefully acknowledged.

eferences

1. Calder A. The science behind recovery: strategies for ath-letes. In: Sports Medicine News, August 2—3, 2001.

2. Connolly DAJ, Brennan KM, Lauzon CD. Effects of activeversus passive recovery on power output during repeatedbouts of short term high intensity exercise. J Sports Sci Med2003;2:47—51.

3. Cochrane DJ. Alternating hot and cold water immersionfor athlete recovery: a review. Phys Ther Sport 2004;5:26—32.

4. Chatham JC. Lactate—–the forgotten fuel. J Physiol Lond2002;542:333.

5. Hahn AG. Training, recovery and overtraining—–the roleof the autonomic nervous system. Sports Coach 1994:29—30.

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6. Enwemeka CS, Allen C, Avila P, Bina J, Konrade J, Munns

S. Soft tissue thermodynamics before, during and after coldpack therapy. Med Sci Sports Exerc 2002;34:45—50.

7. Viitasalo JT, Niemela K, Kaappola R, et al. Warm underwaterwater-jet massage improves recovery from intense physicalexercise. Eur J Appl Physiol 1995;71:431—8.

Available online at www.s

R.H. Morton

8. Coffey V, Leveritt M, Gill N. Effect of recovery modal-

ity on 4-hour repeated treadmill running performance andchanges in physiological variables. J Sci Med Sport 2004;7:1—10.

9. Zar JH. Biostatistical analysis. 2nd ed. Prentice-Hall: Engle-wood Cliffs; 1984. p. 346—7.

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