Periodising recovery strategies: How to use cold water immersion across a season

Cold water immersion (CWI) is much what it sounds like: placing part of the body – from a single limb up through the whole body – into water that’s held at the same temperature for a given duration.^[9] To qualify as “cold” water, it typically needs to be below 20 ºC. Below that, the temperatures can be classified as “severe” (≤ 10 ºC), “moderate” (10-15 ºC) or “mild” (15-20 ºC).

CWI is also part of contrast water therapy (CWT), which involves alternating between cold and hot (38-42 ºC) water. Practitioners can prescribe continuous immersion strategies. Fifteen straight minutes in 15 ºC water would be a long continuous session, while 3-4 alternations between two minutes at 38 ºC and two minutes at 15 ºC is an example of an intermittent session. A continuous session under 10 minutes is considered “short,” and anything between 11-15 minutes is a “medium” length immersion.

Heated debate over post-exercise cold water immersion

As both athletes and the general population widely adopt CWI for post-workout recovery and performance, the debate and skepticism around it has heated up (pun intended).

Recent studies showed an attenuation of muscle size and strength following repeated exposures of post-resistance exercise continuous CWI in untrained and recreationally active participants ^{[2, 10, 13].} This may be the result of the immersion sessions sequentially reducing post-immersion inflammation, which in turn reduces muscle protein synthesis for up to two days post-exercise ^{[10, 11, 13, 23]}. Other studies showed a similar effect when participants underwent severe CWI 2-3 days a week for several months ^[21].

The most significant shortcoming of these studies and the rest of the negative literature on CWI is that the results are not ecologically valid for an elite, high performance training environment. In addition to the non-athlete participants, these studies trained and immersed a single limb. Single limb CWI is a valid concept, but this is clearly not what occurs in high performance sports contexts.

It’s worth noting that this debate does not extend to aerobic exercise modes, as post-aerobic exercise CWI does not attenuate and may even slightly promote aerobic adaptations ^[18,19].

The lack of research on chronic or longer term use of CWI recovery strategies after resistance training in high performance environments creates challenges for practitioners who want to introduce CWI to their players, or who want to systematize their current cold water practices. Some research comparing the effects of CWI on elite level athletes to its effects on recreational participants have found less impact on the athletes.

One recent study highlighted no effect of 15 minutes of post-resistance exercise cold versus hot (15 ºC or 39 ºC, respectively) water immersion on lean muscle mass changes in academy Super Rugby players compared to non-athletes, despite the higher volumes and intensities of training the rugby players endure. ^[25]

Following from recent reviews, our investigations concluded that trained athletes looking to increase lean muscle mass and hypertrophy responses may consider post-resistance exercise CWI in season to facilitate natural adaptation. ^[3,19] This poses a low risk of attenuating increases in lean muscle mass, given the results with the Super Rugby academy players. 

Some athletes have told me that they believe they train harder following post-exercise CWI in subsequent sessions on the same or next day. However, this is purely anecdotal – there is limited research supporting this.

For elite athletes who regularly complete multiple daily training sessions, along with high density training and competition schedules across every level of cycles, we still don’t know whether post-exercise CWI facilitates an athletes’ ability to remain within a chronic inflammatory “sweet spot,” where they can maintain the necessary levels of training volume, intensity and performance while still banking a positive overall training stimulus, leading to increases in lean muscle mass. ^[26] The best we can do is educate ourselves (and each other!) about the advantages of post-resistance exercise CWI for improving biological and perceptual markers of muscle damage and soreness in athletes. ^[27] Then we can have CWI in our tool kit and deploy it when players have two games in a week, extremely hot days between sessions, back-to-back hard days, or when we want to make an intelligent recommendation to an athlete who believes it is the optimal and, therefore, their preferred performance recovery strategy.

Applying basic training concepts to cold water immersion

Periodising recovery strategies

Practitioners who settle on the pro-CWI side of our first question may subsequently immerse themselves in the second debate, centering on periodisation approaches. The idea of recovery periodisation suggests that all recovery strategies, including CWI, are another set of training variables that can be both periodised and programmed to achieve specific recovery, adaptation or performance outcomes. ^[28]

For example, during preseason, should practitioners prescribe increasing levels of recovery strategies in line with increased training loads, or should practitioners deliberately withhold recovery strategies to facilitate natural adaptation?

Programming CWI should proceed along the typical programming variables of frequency, intensity, time and type, using sets and repetitions to manipulate the duration and temperature to achieve the desired acute and chronic physical, physiological, and psychological effects. ^[28] In team sport settings, I periodise CWI to progressively increase athletes’ exposure to cold water across the preseason. Gradually exposing the players to CWI helps them build up to 15 minutes in cold water, which is helpful when athletes initially have an aversion to it.

By simultaneously educating athletes regarding the benefits of CWI while building up their tolerance to it, they can experience and recognize its benefits, allowing practitioners to have their buy in for prescribing it in the critical 48 hours on either side of competition.

Table 1 shows some performance recovery principles I apply. Recovery should be coach guided and player driven, with an emphasis on individual responsibility. In season, athletes have more opportunities to self-select their preferred recovery strategy to cater for these individual differences to leverage any placebo effects from choice, opt in, and buy in. ^[27]

Period	Pre-season	In-season
Goal	1. Maximise adaptation 2. Optimise readiness to train	1. Maximise competition performance 2. Optimise training performance
Programming puzzle (specificity)	How can water immersion be programed to maximise muscular adaptation and readiness to train?	How can water immersion be programmed to maximise performance and pre-training recovery?
Terminology	“Adaptation”	“Recovery” and “performance”
“Big rocks”	Always in combination with sleep, nutrition and hydration
Responsibility	1. Practitioner-guided, player-driven 2. Individual athlete responsibility around “4+20” 3. Focus on education as to “why”
Individuality	Practitioner-guided > athlete choice	Athlete choice > practitioner guided
Overload	0-2 session per week	≥3 session per week
Progression	Prioritise HWI > Progress to CWT/CWI	Prioritise CWI > Periodise use of CWT/HWI

Even in the context of an article talking about the benefits of cold water immersion, it’s essential to recognize that the “big rocks” of recovery are still sleep, nutrition and hydration.

In preseason, the recovery focus is to optimise performance in the next training session; whereas in season, the focus is to obtain maximum or peak performance in the next training session or competition, respectively. Therefore, I prefer the term “muscular adaptation” as the goal during preseason; and “recovery or performance” in season. The focus on muscular adaptation during preseason lends itself to working closely with the performance nutritionist, which sets a good foundation for this relationship across the season.

For post-exercise water immersion, I prescribe heat (via sauna or hot water immersion) to drive muscular and cardiovascular adaptation ^[29], and CWI or contrast water immersion to optimise recovery and maximise performance, given its role in reducing perceived muscle soreness and muscle damage biomarkers. ^[27]

Athletes often report feeling fresher post-CWI, so we should aim to always finish any immersion session in the cold.

Hydrotherapy can also promote sleep onset via tympanic regulation, with the core body temperature decreasing in warmer environments and heating up during cooler conditions. We can manipulate and facilitate this process by having athletes complete evening hydrotherapy sessions to help with sleep onset, contrasting the water temperatures to whatever the weather conditions outside. Table 2 is a sample preseason performance recovery model for a team sport, illustrating different performance recovery strategies up to the preseason trial games. During the trial game period, we shift to in season performance recovery strategies. Note the progression of prioritising HWI before increasingly applying cryotherapy via either CWT or CWI as we approach the competitive season.

20XX – 20XX PRE-SEASON PERFORMANCE RECOVERY MODEL
Training week		44	45	46	47	48
Pre-season week		Leave 1	Leave 2	1	2	3
Recovery		Self-directed choice, prioritising ‘other’ & ‘mindset’		Strategy A: Heat (pre- or post-gym and post-field), massage, compression, flex, no/minimal cryo
Individual recovery strategies	Regeneration (sleep;napping)
	Hydro-nutrition (integrated as per nutritionist guidelines)
	Cryotherapy
	Thermotherapy (heating)
	Compression
	Massage
	Mindset
	Mobility/flexibility
	Other (rest and relaxation; active; passive)

20XX – 20XX PRE-SEASON PERFORMANCE RECOVERY MODEL
Training week		49	50	51	52	1	2	3
Pre-season week		4	5	Christmas	New Years	7	8	Trial 1
Recovery		Strategy B: As per A, plus intro cyro (post-session, bet. back up days) and mindset		Self-directed choice, prioritising ‘other’ & ‘mindset’		Strategy A: Heat (pre- or post-gym, post-field) massage, compression, flex… no/minimal cyro		Strategy B: As per A, introduce cryo (post-session, bet. back up days) and mindset; trial in-season protocols
Individual recovery strategies	Regeneration (sleep;napping)
	Hydro-nutrition (integrated as per nutritionist guidelines)
	Cryotherapy
	Thermotherapy (heating)
	Compression
	Massage
	Mindset
	Mobility/flexibility
	Other (rest and relaxation; active; passive)

Overloading recovery?

If we are applying the concept of periodisation to recovery strategy, it’s only logical that we apply other principles of training, as well.

The principle of overload applies to water immersion, with one approach being to increase the frequency of water immersion sessions approaching competition. This reduces muscle damage, swelling and soreness following resistance exercise in athletes. ^[27]

Practitioners can also increase the overall dose of CWI per session by increasing exposure time, as the team approaches the end of preseason and then during in season competition. I recommend a maximum of 15 minutes per water immersion session, acknowledging the other competing post-exercise recovery time demands, e.g., sleep, nutrition, hydration. Given the dose-response relationship at work in post-exercise CWI, I set the upper limit at either five minutes at 5 °C, 10 minutes at 10 °C or 15 minutes at 15 °C. ^[38,39] 

Individualizing CWI: Responsibility and ownership of recovery

The results of our studies investigating the effect of post-resistance exercise water immersion demonstrate high individual variability in short (< 48 hours) and medium to long term (up to four weeks) responses via recovery, adaptation and performance measures (25). ^[25,27,29] These results support an individualised approach to performance planning and performance recovery prescription.

One approach I take in season is prescribing a small number of water immersion strategy options for the players. The athletes are then free to choose their preferred option, hopefully facilitating buy in by placing the responsibility on them to complete their recovery session. This allows the athletes as individuals or even position groups to figure out what works for them. Some tall second row locks I have worked with in rugby union report their backs stiffening following CWI, so it would be counterproductive along many dimensions to require CWI for these players.

An analogy I like to use with players is that 1% of their day is about 15 minutes, so if, at minimum, they believe they can improve their performance or recovery response by at least 1% through some form of post-exercise immersion, it is a worthwhile investment to accrue those marginal gains.

Giving the players ownership of their recovery also sidesteps the risk of practitioners who might push either the workout or the CWI too far. On the one hand, they could justify overloading the players by pointing to the post-workout CWI session; or they could over-prescribe and overdo the recovery strategies and diminish the benefits of the recovery on the adaptations they seek.

It is good practice for practitioners to use post-exercise recovery surveys to better understand previous athlete usage and preference, and then use this information when developing individual or team recovery strategies. ^[31,32]

When you have athletes who have not experienced some of your go-to recovery modalities, preseason preparation periods are a great opportunity to expose them to a variety of water immersions, such as CWI, CWT, HWI, pool active recovery, as well outdoor options like the sea, lakes and rivers, where available.

Practitioners should encourage all athletes to keep journals during preseason to reflect on how they felt and performed in sessions following different workouts, games and recovery strategies. Then they, either on their own or with a practitioner, can really home in on what works best under any set of subjective states or objective conditions.

Figure 1 is a scale I used to understand athletes’ beliefs regarding the effectiveness of post-exercise CWI for improving recovery, reducing muscle soreness, and enhancing muscular adaptation and performance. This was in an applied research setting, with athletes from an international Olympic training centre. It is crucial to understand these beliefs, as we know that the combination of a recovery strategy with a belief in the efficacy of that strategy improves biological and perceptual markers of muscle damage and soreness. ^[27]

Practitioners should also consider athlete body composition when individualising post-resistance exercise water immersion. Females have a different distribution of adipose tissue (higher subcutaneous fat thickness and an increased surface area to body mass ratio) than males. ^[33] Along with blood flow, this alters the level of cooling ^[34] and further influences the physiological and subsequent body composition responses to post-resistance exercise water immersion.^[35–37]

Programming cold water immersion for teams and individuals

These insights have the greatest application to high performance athletes who typically train multiple times per day, at least five days per week, in high performance training centres or environments for their tactical, technical and physical preparation requirements. Practitioners should be careful when interpreting and transferring research outcomes that investigated responses following single limb training or immersion protocols using non-athlete, recreational participants.

Both athletes and practitioners should be of the mindset that post-exercise recovery occurs right up to the start of the next session, to maximise the adaptive and performance responses from the previous session. Table 3 shows a sample week of in season training and recovery for a professional rugby union team.

Day	Monday	Tuesday	Wednesday	Thursday (MD-1)	Friday (MD)	Saturday (MD+1)	Sunday
AM	Pre-session preparation: · 15’ HWI, stretch and prep   Team pitch session (high volume, high intensity; technical and tactical focus under fatigue)	Pre-session preparation: · 15’ HWI, stretch and prep   Weights: Whole body power   Team pitch session (moderate volume, high intensity; technical and tactical focus with intensity)	Rest and recovery	Team “captain’s run” pitch session (low volume, high intensity; technical and tactical focus)			Pre-session preparation: · 15’ HWI, stretch and prep · 30’ yoga   Team pitch session (low volume, low intensity; technical and tactical learning focus)
Noon	Recovery: · 3’ x 30 sec contrast showers @ 1:1	Team lunch   Regeneration: · 30’ massage · 30’ flexibility 15’ hydrotherapy	Recovery: · Sleep / nap at home after lunch (30-45min)	Recovery: · If sore: 5’ HWI + 10’ CWI* · If tight / stiff: 15’ CWT @ 1:1 for 7 x 2’ each If they feel good: 15’ Athletes’ choice			Team lunch
PM	Weights: Upper body strength   Recovery: H:C=1:0: · 7.5’ Sauna, · 7.5’ HWI OR · 15’ Sauna OR · 15’ HWI and protein shake + hydration	Recovery: During regeneration block: 15’ x Freestyle (athlete choice)	Big rocks: · Sleep 8+ hours · Nutrition and hydration Rest and recovery (mind set)		Rd.1 v Opponent (Home)   Post-game: · Protein shake · 15’ or 3×5’ CWI @ H:C =0:1		Weights: Lower body strength   Recovery: Contrast @ H:C=1:1 Option 1: x 7 each · 1’ HWI, and · 1’ CWI. Option 2: x 2 each · 3.5’ HWI, and · 3.5’ CWI.

Practitioners and athletes do not require a state of the art high performance recovery facility to incorporate water immersion. Athletes can do it at home in a cold water baths keeping in line with  the time and temperature guidelines. When full immersion is not possible or practical, cold showers are also a good alternative ^[40]. And, when suitable and safe, outdoor natural water – lakes, rivers, the sea – can inject some variety to the training regimen and enhance team cohesion and camarederie.

Case study #1: Squad recovery in 15 minutes

Post-training or post-competition, there is only a narrow window of opportunity for recovery. Along with the prescriptive elements from the preceding sections, practitioners also need to account for the logistics: time available, number of players and available facilities. Those will differ between home and away games, before we even start to talk about individual differences.

These scenarios push us to be creative in how we maximise what is available to us. Sometimes we have to content ourselves with practices based on a “do no harm” approach. For example, when post-match recovery facilities are limited in size or capacity, it might be better for the (non-injured) players to complete a contrast water immersion circuit alternating between cold and hot pools, instead of having the whole group standing around in a line waiting for a cold pool only. The hydrostatic effects of water immersion decrease muscle damage biomarkers, e.g., creatine kinase, irrespective of temperature through their impact on blood flow. We ensure the players at least get that, even if it’s not our “ideal” use of water.

Recently, I had a group of 25-30 players in a performance recovery facility the day after a match. The facility had a cold pool, hot pool and sauna that could each take a maximum of four players at a time.

Working within those constraints, I had 12 players cycle through two sets of two minute reps in whole body CWI, HWI and sauna, with one minute to move between modalities. That resulted in a total of a 17 minute hydrotherapy circuit.

Other practical considerations are cold pool temperatures, which may increase when large groups are using them. If the cooling systems can’t keep up with the number and body temperature of the players, and the amount of time the players spend in the pool, those players in the later groups might be getting into water that is warmer temperature than what their teammates had.

Contrast showers are an option to keep water temperature consistent across larger groups, and be more time efficient. A basic performance recovery strategy can be five reps of 30 seconds hot shower followed by 30 seconds cold shower, ideally always finishing any strategy with cold to obtain feelings of freshness and revitalisation at the end.

If I have access to a pool for a minimum of 15 minutes, I lead an active recovery session (see below), which is like a dynamic warm up. We bring the athlete through a combination of jogging or swimming for aerobic recovery. Jogging is usually better for team sports, as the players may not be particularly proficient swimmers. Either way, the focus is on keeping athletes moving, and then bringing in some functional movements and dynamic stretches followed by static stretches to complete the session.

Circuit 1 – 7.5 mins

1. Swim/Jog two lengths @ “easy pace”
2. Functional Movement 1
   1. Walking high-knee and pull to chest & swim/jog to end
   1. Heel-flicks & swim/jog to end
   1. A-Drilling & swim/jog to end
   1. Up and over-the-fence (groin mobility) & swim/jog to end
   1. Stationary Leg Swings – Forwards, Backwards & Lateral
3. Static Stretching 1 (30secs per stretch)
   1. Quads / Hamstrings / Glutes / Upper-body Stretch

Circuit 2 – 7.5 mins

1. Swim/Jog four lengths @ “3/4 pace”
2. Functional Movement 2
   1. Walking Forward/Backwards Lunge + Trunk Rotation & swim/jog to end
   1. Walking Sumo Squats w.180° turn & swim/jog to end
   1. Walking Quad Stretch w. Calf Raise & swim/jog to end
   1. In reverse, walking SL RDL + reach & swim/jog to end
3. Static Stretching 2
   1. Hip Flexors / Groins / Calves / Upper-body Stretch

If we can only use one lane of the pool, I’ll line players up and will move all the squad simultaneously in a circular manner from start to finish, performing different activities each lap or length (see below). Incorporating some fun partner resisted exercises at the start, middle and end of the session help with the mood of the group and overall session enjoyment.

Natural, outdoor water is another good option when it is available and facilities are limited. Being in an 8-15 °C river or sea will push athletes just enough outside of their comfort zones (in Ireland anyway!), and the experience lends itself to team bonding. Players typically have good fun in these settings since they are outdoors and away from the daily training environment. That also adds some beneficial (sometimes essential) variation to the program schedule.

And when competition ends late in the evening and there are no recovery facilities on site, we stick with the “big rocks” of recovery: nutrition, hydration and sleep, complemented by an extensive static stretch immediately post-exercise. I encourage contrast showers as a water based recovery strategy that is almost always available, and then follow up with a full performance recovery protocol on MD+1.

Case study #2: Individual player programming

One of the rewards of developing athletes’ trust and buy in is when they come to you one-on-one for a personalized MD+1 recovery session. An athlete who had two games in two days recognized that he needed a full out professional, systematic, practitioner-led recovery strategy that took advantage of everything that was available to him.

My recommendation to him was:

– 15 minutes off-feet cardio spin in zone 1 (100-120 bpm, or RPE 1-2 out of 10) for active recovery

– 45 minutes foam rolling, flexibility and mobility, per the fitness staff’s guidelines

– Protein milk, protein shake or equivalent, in accordance with the nutritionist’s guidelines

– Contrast water therapy: alternating the hot and cold pools for seven reps of two minutes each, starting and finishing with the cold pool and immersing the whole body up to the neck

– 15 minutes sauna to “relax,” followed by a one minute cold shower to refresh

– 15 minutes compression boots to fully chill out!

And, of course, maintain hydration throughout.

Later that afternoon, he sent me a screen cap showing his recovery activities and metrics, giving me a chance not just to track his compliance but to continue refining recovery strategies for him, individually, and any other athlete.

Developing a cold team culture (in a good way!)

Athletes spend approximately ≥ 20 hours between scheduled training activities each day. How they spend that time will determine the adaptive and performance responses obtained from training. Like any other aspect of training, when it comes to recovery strategies practitioners have to teach and mentor while they are prescribing and programming.

When setting up any performance recovery program, we should consider how we work with the playing group. Practitioners should work closely with sport coaches, the team captain and the leaders amongst the players to build the culture, behaviours and habits that positively promote performance recovery. We have to factor in what the team or organization has been doing up to this point and where the playing group is on this journey. Before we start talking about cold water therapy, we should make sure they know what foam rollers are. And, before that, we should ensure they are moving those “big rocks” of recovery.

By progressing in a logical and needs oriented fashion, we can build towards a practitioner guided, player driven model of recovery programming. When that happens, we’ll be as comfortable talking to each athlete about the time and temperature for cold water immersion as we currently talk about weight, reps and sets of their favorite lift.