4.1 Sleep

Sleep should be one of the cornerstones of any athlete’s recovery and performance strategy. This sub-section will provide a brief overview relating to how sleep influences both physical and cognitive performance. Melatonin is a hormone produced by the pineal gland within the brain, with the onset of secretion occurring approximately 2 h prior to habitual bedtime (termed dim light melatonin onset) and aligning with the start of the biological night [25]. Its production follows a circadian rhythm, which in turn, is regulated by a central “master clock”, the suprachiasmatic nucleus, as well as peripheral clocks located in most cells of the body. The master and peripheral clocks of the circadian system synchronise through zeitgebers or time-givers. The most common time-givers are: sleep–wake transition, physical activity, social cues, meals and light, with the latter regarded as the most influential given that photic stimuli (via the retino-hypothalamic pathway), stimulates or inhibits the suprachiasmatic nucleus [25]. For example, exposure to light, especially blue light from screens, can inhibit melatonin production, which is why reducing screen time and dimming the lights before bed is often recommended to promote better sleep quality, as is ensuring the room is as dark as possible. Additionally, our body’s circadian rhythm naturally causes a drop in core body temperature throughout the evening (reaching a nadir at approximately 04:00 depending on chronotype), further stimulating sleep as well as the maintenance of it. This is why athletes are often advised to keep their bedroom cool at night and some also advise taking a warm bath before bed, with the latter facilitating the natural decline in core temperature that occurs before sleep. This cooling process signals to the brain that it is time to prepare for sleep, promoting relaxation and drowsiness.

Sleep is crucial for physical and cognitive performance, as well as recovery and adaptation. It is often labelled the “big rock” of recovery as its positive effects are significant [26], yet athletes (and golfers in particular) face challenges in optimising sleep. As such, educating players and providing guidelines for sleep hygiene is fundamental practice by performance and coaching staff. By way of example, in 146 Brazilian Olympic athletes preparing for the Rio 2016 Games, it was found that 36% had a sleep disorder, and 53% of athletes reported sleep complaints, with the most prevalent being insufficient sleep or waking up tired (32%), followed by snoring (21%), and insomnia (19.2%) [27].

With respect to physical performance and recovery, sleep allows for muscle growth and repair (as well as bone and body fat mass regulation), facilitated principally by the release of growth hormone occurring during the early stages of sleep [28]. Furthermore, there is a down-regulation of the hypothalamic–pituitary–adrenal axis and the sympathetic nervous system and, thus decreases in plasma cortisol, epinephrine and norepinephrine levels [29]. Sleep also restores energy stores by replenishing glycogen and strengthens the immune system by producing cytokines that help fight infection and inflammation [30]. Equally, good sleep improves coordination and reaction times, and reduces the perception of effort, meaning athletes can train with greater intensity. For example, following approximately 30 h of acute sleep deprivation in team-sport athletes, significant decrements in performance were noted including: reduced repeat sprint ability, muscle glycogen content, peak voluntary force and activation, and negative perceptual strain [31].

From a cognitive standpoint, sleep plays a key role in memory consolidation by transferring short-term memories to long-term storage during rapid eye movement sleep [32]. It enhances learning and problem-solving abilities, assists with concentration and decision making, and also helps regulate emotions and reduces stress [33]. During sleep, particularly in rapid eye movement stages, the brain processes emotional experiences, helping to reduce the emotional intensity of those experiences and improve mood regulation. Conversely, a lack of sleep can lead to increased levels of stress hormones such as cortisol, resulting in irritability and fluctuations in mood. Sleep is also essential for regulating hormones that control hunger and appetite [34]. During sleep, the body balances the levels of ghrelin and leptin, hormones that signal hunger and fullness, respectively. Conversely, a lack of sleep increases ghrelin levels and decreases leptin levels, leading to increased hunger (and potentially calorie intake). Poor sleep can also lead to increased blood pressure, higher levels of stress hormones and inflammation, all of which are risk factors for various cardiometabolic diseases.

Naturally, obtaining optimal and good-quality sleep for any athlete is essential to help optimise recovery. However, owing to the changing time zones and accompanying jet lag (discussed in the next section), this is a considerable challenge for professional and elite amateur golfers. Regardless, to improve both sleep onset and quality, below are some guidelines for practicing good sleep hygiene [26]. Of note, some of the suggestions below will only be achievable for golfers when not travelling and/or are based in one location for an extended period of time.

Maintain a consistent sleep schedule: Going to bed and waking up at a similar time every day supports the regulation of the body’s internal clock, making it easier to fall asleep and wake up naturally. This can also reduce cortisol levels and muscle catabolism, which may potentially enhance performance [35].

Create a relaxing bedtime routine: Identifying individualised stress-reducing and calming activities such as reading, taking a warm bath or practicing relaxation exercises (e.g. meditation or deep breathing exercises) provides a signal to the body that it is time to relax, helping a more natural transition into sleep [36].

Bedroom temperature: Keep the bedroom cool, ideally between 60 and 67 °F (15–19 °C). A cooler room temperature helps facilitate the natural drop in core body temperature that occurs during sleep and as part of our circadian rhythm [37].

Ensure darkness in the bedroom: Use blackout curtains or an eye mask to create a dark sleep environment. Darkness signals to the brain that it is night time and helps regulate the production of melatonin, the hormone that promotes sleep [38]. Light exposure, especially blue lights from electronic devices and artificial sources, suppresses melatonin production and delays the onset of sleepiness.

Watch the diet: Avoiding heavy meals, caffeine and alcohol close to bedtime prevents disruptions in sleep caused by indigestion or the stimulant effects of caffeine and alcohol. Caffeine, in particular, can delay the release of melatonin, and block adenosine receptors, thus temporarily promoting alertness, making it harder to both fall asleep and stay asleep [39]. Given caffeine has a half-life that varies between 2.7 and 9.9 h, ideally individualised advice should be offered. However, generic guidance would be to avoid caffeine after 14:00 unless used as a performance enhancement strategy during competition [40].

Stay active: Regular physical activity promotes better sleep by reducing stress and tiring the body, resulting in the accumulation of adenosine molecules. However, avoiding vigorous exercise close to bedtime limits stimulation of the sympathetic nervous system and thus, increased concentrations of adrenaline and noradrenaline. These “fight or flight” hormones increase heart rate, blood pressure and alertness, which are counterproductive to the relaxation needed for sleep [41].

4.2 Travel Fatigue and Jet Lag Management for Golf Recovery

As highlighted in Sect. 1, professional golf tours have schedules that include tournaments on multiple continents, with frequent transitions between time zones [2]. Naturally, this has an interrupting effect on critical components of recovery, such as consistent sleep patterns [26]. The combined demands of travel and regular time zone changes (i.e. travel fatigue and jet lag) can challenge physical function and cognitive recovery in golfers. Athletes participating in sports with less frequent travel can employ pre-adaptation, phase-advance or phase-delay strategies, depending on their direction of travel [2, 25, 42,43,44], some of which can be used by golfers for priority competitions. Such strategies include adjusting the time an athlete goes to bed or wakes up 3–4 days before travel, altering their light exposure throughout the day, as well as manipulating the timing of their meals [2, 43]. However, golfers can only employ some of these strategies consistently, owing to weekly competition schedules being in a variety of different locations globally. As a result of these frequent changes in location and time zones, we recommend that players invest in a “toolbox” of simple and ‘easy to adhere to’ travel strategies that can be employed immediately post-competition on a Sunday evening (assuming they make the cut) to help them prepare for the next event. Whilst an individualized approach is always preferable, we have built on the existing literature to describe a series of practical strategies broken down into graded steps spread across the different stages of travel, that golfers will experience.

4.2.1 Step 1: Distinguish Between Travel Fatigue and Jet Lag

Travel fatigue is defined as temporary travel-related fatigue or exhaustion and can follow any long journey, including: car, bus and train trips even without crossing time zones. It follows a period of prolonged inactivity, with potentially irregular sleep, restricted food choices, dehydration and other factors associated with long-distance travel [2, 42, 43]. Jet lag may co-exist with travel fatigue but follows rapid long-distance travel, crossing three or more time zones. It is caused by rapid trans-meridian travel and the body clock becoming discordant with the time zone at the new destination [2, 25, 42, 43].

4.2.2 Step 2: Immediately Post-competition

In the immediate post-competition phase the focus should be on acute recovery for golfers. The energy cost of a round of golf during competition can exceed 1000 kilo-calories [45], although the exact value will be specific to the individual and the topography of the course. In addition to this energy expenditure, there may be some glycogen depletion, muscle damage and dehydration [46]. To address these needs, golfers are advised to repair potentially damaged muscle with high-quality protein, replenish fuel stores with appropriate amounts of carbohydrates, and rehydrate with fluids and electrolytes [46, 47]. Should players have more time, they can complement this with modalities such as cognitive recovery, hands-on massage, compression garments and general relaxation, followed by an additional recovery meal and good quality and quantity of sleep if possible [25, 43]. Finally, when playing multiple tournaments in a row, players are encouraged to plan as much as possible in advance, to reduce unnecessary stress and anxiety. Some suggestions from Dunne et al. [2] include:

Ensure documentation is in order (e.g. passport and visa if required).

Take the most direct route to the next destination, with the least number of stopovers.

Get enough sleep and rest before the journey.

Prevent illness, by developing consistent good habits (e.g. enough rest and sleep, well-balanced nutrition and hydration, use of antibacterial hand gel).

4.2.3 Step 3: At the Airport

Attention for golfers at the airport should now shift towards preparing for travel, including purchasing some airport essentials. Following check-in and proceeding through airport security, players should purchase antibacterial hand gel, if they do not have any already, for regular use throughout the trip. Depending on the duration of travel, golfers should also consider purchasing some travel meals, snacks and water, as the food service provided by airlines can sometimes be unreliable, and the in-flight service also has the potential to disturb sleep.

4.2.4 Step 4: During Travel

First, during travel golfers may wish to change the time zones on their devices (e.g. phone or watch) to that of the new destination. To support quality sleep, they are advised to align their sleep with the place of departure as their psychological drive for this rest is higher, making sleep easier to initiate. Should golfers struggle to sleep consistently, then a ‘sleep-when-possible’ approach is advised during travel. Added considerations include: (i) good-quality ear plugs; (ii) an eye mask to block out light; and (iii) recovery leggings or flight socks to aid venous return and decrease the risk of deep vein thrombosis. If golfers purchase food in the airport to consume during travel, then an in-flight meal and snack timings may be adjusted according to the destination time zone [42,43,44]. Food choices should remain familiar with new foods being avoided where possible. In addition to planning their meal timing, golfers are advised to follow a pattern of eating regular small meals to meet their energy requirements and avoid deficiencies. Consuming regular but smaller meals containing sufficient protein, micronutrients and fibre (e.g. fresh or dried fruit), pre-prepared by the athlete or their team, will aid recovery and support immune function [2].

Throughout the flight, golfers should get as much rest and sleep as possible. They are advised to drink regularly and follow a hydration plan that was configured pre-travel. Regular sips of non-alcoholic and non-carbonated drinks are best, with priority given to water with electrolytes [47]. Naturally, alcohol and caffeine should be avoided or limited. The recycled air of the aircraft makes it easier to lose moisture during breathing, which has the capacity to increase dehydration, which in turn, can increase the risk of contracting an illness [2, 25, 42,43,44]. Needing to visit the bathroom relatively regularly throughout the flight is a useful practical indicator that the player is drinking enough. In addition to staying hydrated, chewing gum can also aid the production of salivary immunoglobulin A and reduce the risk of infection [2]. Finally, when awake, stretching and, if possible, doing some movement-related exercises up and down the aisle is advised to retain sufficient joint mobility.

4.2.5 Step 5: Arrival at New Destination

Having arrived at the new destination, the full focus is now on recovering from the flight and preparing for the competition likely starting on Thursday. Given the need for golfers to be able to get into the desired swing positions, some level of mobility work and foam rolling is advised within the first 24 h of landing to help restore range of motion and reduce joint stiffness [48]. In addition, it is suggested that relevant mobility work is repeated as part of a routine warm-up, prior to practice and competition, as some effects are unlikely to last beyond 10–15 min [49]. Finally, heavy or intense resistance training should be adapted if golfers feel fatigued or sluggish.

4.3 Nutrition and Hydration Strategies for Golf Recovery

Prior literature has undertaken a more in-depth analysis of the nutrition and hydration requirements for professional and elite amateur golfers [46, 47, 50,51,52,53], and readers are directed to these for a more in-depth overview, specific to nutrition and hydration alone. Naturally, good-quality nutrition and hydration habits are essential to help any athlete optimise their recovery after training and competition [54,55,56]. When considering requirements specific to golf, tournaments are often played in a hot environment, for an extended period of time; thus, we can break recovery strategies down into three key timepoints each day: (i) post-competition; (ii) evening; and (iii) pre-bed. As a golfer comes off the course, it is suggested that they focus on the three Rs of recovery: (i) rehydrate; (ii) repair (damaged tissue with high-quality protein); and (iii) restore (depleted energy stores with appropriate carbohydrates).

4.3.1 Post-round

Rehydrate: golfers should aim to consume 1.5 L of water for every 1 kg of weight lost during a round [57]. Additionally, players should also aim to include some electrolytes post-round to ensure salt that is lost through sweat is replaced, although this does not necessarily require specific drinks given that these electrolytes are also readily available in many foods commonly consumed post-exercise.

Repair: golfers should consume at least 20–40 g of high-quality protein soon after a round. This can be achieved by having meat-, fish- or plant-based protein foods available in the players’ lounge as part of a post-round meal. If a player has many media responsibilities or wants to go straight back to practice, nuts, milk, Greek yoghurts or dairy-based smoothies are also viable options. Adding two to three servings of fruit and/or vegetables alongside the aforementioned dairy options post-round also supplies some additional antioxidants that may further aid repair [46].

Restore: restoring depleted fuel stores can be achieved by having some high-quality carbohydrates in a post-round meal, such as pasta, potatoes or rice. In addition, adding some fruit will add additional fructose to the meal, which has been suggested to be important in the replacement of liver glycogen [58].

4.3.2 Evening and Pre-bed

For evening meals, the focus is comparable to previous suggestions. Adequate hydration in the evening helps players continually replace the fluids lost during the day and puts them in a better position to wake up hydrated for competition the following day. Ensuring a regular supply of quality protein ensures the muscles have the raw materials required to continue to repair themselves. Finally, including carbohydrates in the evening meal, will help replenish depleted muscle and/or liver glycogen stores. Pre-bed, the focus should be on delivering some high-quality protein to aid overnight recovery given that pre-bed ingestion of protein has been shown to increase both mitochondrial and myofibrillar muscle protein synthesis [59]. With this in mind, one option for golfers is Greek yoghurt, which should be easily accessible, regardless of which country they are competing in, helping to promote a ‘food first’ approach to sport nutrition [60].

4.4 Controlled Environment Strategies for Golf Recovery4.4.1 Massage

While there are various types of massage, very few studies have been conducted specifically in golf. Lim [61] recruited 20 golfers of varying experience levels to use a massage chair for 20 min, focusing on treatment around the gluteal, lower and upper back muscles. The results showed significant improvements (p ≤ 0.03) in clubhead speed (CHS), ball speed, carry and total distance. Despite these positive findings, it seems conceivable that improvements in tissue extensibility were a result of improvements in perceived recovery or increases in tissue temperature. It is important to note, though, that tissue temperature was not measured; however, this seems like a plausible explanation when the duration of the intervention was 20 min. Thus, a well-designed warm-up routine may offer comparable benefits [12]. In support of this, Quinn et al. [62] undertook a comparison of trigger point therapy in the hip flexor muscle with medicine ball exercises versus trigger point therapy (again in the hip flexor) with stretching of the same muscle group on CHS, ball speed, distance and smash factor in 100 male golfers. Although raw data were not reported, the group that included medicine ball throws significantly improved their backswing hip turn (p = 0.02) and accuracy (p = 0.02) relative to the control group. To the authors’ knowledge, this represents all the information pertaining to empirical studies investigating the effects of massage on golfers. However, some broader benefits may also exist, which should be acknowledged based on the wider literature. First, massage may provide some acute improvements in range of motion and delayed-onset muscle soreness (DOMS) [63]. Additionally, the mechanical pressure on muscles may induce changes in parasympathetic activity (e.g. heart rate, blood pressure, heart rate variability) and hormonal levels (e.g. cortisol) that enhance a player’s ability to relax post-competition [63]. Moreover, including massage as a part of regular recovery regimens may reduce an athlete’s anxiety and improve their mood and wider cognitive state, which can additionally optimise recovery [63]. Thus, despite the limited amount of empirical investigations conducted in golf specifically, massage may still have its place in the over-arching recovery process for golfers, especially in areas that are prone to injuries such as the lower back, wrist, elbow and neck [64, 65]. Specifically, for players who feel stiff or sluggish, massage may be a useful strategy prior to starting a warm-up routine, given that previous research has shown no detrimental effect on subsequent performance (albeit in the sport of boxing) [66].

4.4.2 Cold Therapies Including Cold Plunges and Ice Baths

Cold therapies (or cryotherapy) is a term that can be used to describe numerous treatments that focus on the application of ‘cold’ to elicit therapeutic benefits [67]. By facilitating heat dissipation, cryotherapy can reduce tissue and core temperatures to mitigate thermal strain [68]. Concurrently, it can also alter muscle blood flow to reduce inflammatory responses and secondary tissue damage [69], and provide analgesic effects through decreased neural conductivity, enhancing perceptual recovery [70, 71]. The use of cryotherapy for athletic recovery has been steadily increasing over the last 70 years, and in the last decade, the development of cold plunges, whole-body cryotherapy chambers, portable cryo-pneumatic systems and phase change materials has meant that practitioners and athletes have numerous options to choose from [72].

Outdoor sports such as golf require athletes to contend with fluctuations in the natural environment that could impact on their performance. Given that an 18-hole round is expected to take 5–6 h, and that tournaments are usually conducted over several consecutive days, golfers can be exposed to moderate or high thermal loads [73], which can potentially reduce motor-cognitive performance or increase central nervous system fatigue [74]. For example, during the FedEx St. Jude Championship playoffs held in Memphis, Tennessee in August 2023, temperatures reached 43.9 °C (111 °F) [75], with similar conditions experienced at the following tournament in Atlanta. Cold therapy strategies can be used both during and immediately post-round to mitigate the negative impacts of excess heat storage on performance and subsequent recovery. During rounds, cold towels around the neck or even ice vests could be an option when players are waiting to play their next shot (noting that wait times can range between 5 and 15 min), to reduce heat storage and skin temperature [76]. During play, cooling during very hot and humid conditions can be further enhanced by replacing traditional ice packs with an alternative phase-change material with a set point of 15 °C, which can safely provide > 3 h of constant cooling, by seeking shade, and ingesting cold fluids [77].

An 18-hole round of golf in a professional competitive setting is considered moderate-level aerobic physical activity [45]; however, average energy expenditure data do not consider dynamic explosive movements such as those typified by a golf swing. Although research into exercise-induced muscle damage is notably sparse in golf, evidence suggests that an 18-hole round of golf can elicit increases in inflammation, and result in structural muscle damage in healthy young men [