Anton Dubrov, Aryna Sabalenka’s coach. Photo: Unbox Sports
The coaches behind top tennis players agree: sleep is not a luxury.
When a professional tennis player loses a match, the next conversation usually focuses on tactics, footwork, or serve percentage. The conversation rarely starts with the previous night But information like what time the athlete went to bed, whether the sleep environment was cool enough, and whether their body actually recovered are critical pieces of information. The coaches who build and protect careers at the highest level know this and are asking these questions. Every morning, before a single ball is struck, they want to know: how did Sabalenka, or Fritz, sleep?
We sat down with three of the best in the business, Michael Russell, James Delgado, and Anton Dubrov, to understand how sleep fits into the architecture of elite performance. What they shared was direct, evidence-backed, and at times surprising.
Sleep is a training block: not a recovery afterthought
All three coaches use identical language when they talk about sleep: it is part of training, not separate from it. Anton Dubrov is the most explicit.
“I always think about sleep as one part of training. Most adaptation, everything we practice on the court, happens during sleep, especially deep sleep. The better you sleep, the better you will perform. No matter how hard you train, if you are under-recovered all the time, it is not going to help you.”
— Anton Dubrov, coach of Aryna Sabalenka
Michael Russell builds this directly into Taylor Fritz’s programme. The target is nine hours of sleep per night, not as a stretch goal, but as a baseline non-negotiable. “We really stress the nine-hour sleep,” Russell explains. “That is where you can hit the deep REM state and you genuinely feel better the next day. If Taylor plays a five-hour match in 100-degree heat and is really putting his body through it, he needs nine hours or more. That is not optional.”
Jamie Delgado takes it further. At morning team meeting, the first question asked every day, before training loads, tactics, or scheduling, is: how did you sleep? The answer dictates how the day is structured. “If he has not slept well, it affects quality,” Delgado says. “You are losing days. We cannot afford to have too many average sessions or miss days. You start falling behind.”
Jamie Delgado. Photo: Unbox Sports
Sleep vs. recovery tools: the late-night decision
One of the most revealing moments in the interviews came when coaches were asked about a scenario every tennis team faces: a late-night match finish, an early start the next day, and a choice between physio treatment and sleep.
Both Russell and Delgado gave the same answer independently. Sleep wins.
Delgado referenced a decision made just days before the interview, during the Indian Wells tournament:
“We had a late match and a big decision on how much treatment he had that night, because he was playing the next day. We actually cut down the physio treatment to get the sleep. We put sleep first. Because during sleep your body is recovering, doing real repair. It is just as important as what the physio is doing. Probably more.”
— James Delgado
Anton Dubrov adds important nuance on timing: after a late match, he recommends a seven-to-ten-minute bike cooldown, food, and 60 to 90 minutes to decompress — then bed. Not two hours of treatment. Not cycling for half an hour to check a box. “Prioritise sleep. It is more important. The longer you delay your sleep, the worse the recovery. Get out of the venue, go to your room, shower, and sleep.”
Michael Russell — Coach of Taylor Fritz. Photo: gettyimages
Temperature, environment, and the problem of travel
All three coaches converge on the same three environmental conditions for quality sleep: darkness, quiet, and cool temperature. But consistently achieving those three things while travelling 35 to 40 weeks a year is another matter entirely.
Russell frames it simply: “Dark. Cool. Quiet. If you can keep all three, that is ideal for finding optimal sleep.”
Dubrov is particular about temperature. His optimal sleep temperature is 68°F (20°C), and he points to the science clearly:
“So many studies show that a cooler room is much better for deep sleep. You can even drop one or two degrees lower than you think is comfortable and it is actually going to help you even more with recovery. Some athletes sleep at 16°C, which sounds like a freezer. But if it works and you feel better for it, why not?”
— Anton Dubrov, coach of Aryna Sabalenka
It is exactly the range the Pod by Eight Sleep is designed to maintain, removing the hotel room variable for athletes who cannot afford to leave temperature to chance.
Dubrov travels with the same pillow everywhere. He deliberately requests rooms on higher floors, away from elevators and street noise. He uses blackout curtains and, critically, only books rooms with functioning air conditioning. “We can spend thousands of dollars on the right shoes, rackets, and strings,” he says, “but then arrive at a hotel with a random pillow, no AC, and no blackout curtains, and not think about recovery at all. It makes no sense.”
Jamie Delgado raises a challenge familiar to many British athletes and coaches: summer heat with no air conditioning. Wimbledon, the most important grass-court event in the world, falls during the UK’s hottest weeks, and most homes and hotels in Britain are not air-conditioned. “It seems crazy that during the most important time of the year, you cannot get the basics of a good rest right. This year will be the first summer I have Eight Sleep in the UK. I have thought about it a lot… how much better I am going to feel.”
Anton Dubrov and Jamie Delago. Photo: Unbox Sports
Sleep, injury, and the red zone
One of the clearest connections coaches draw is between sleep deprivation and injury risk. It is not theoretical for Delgado.
“If the player starts going into what we call “the red zone”, fatigue, overtrained, that is when injuries creep up. The stats show it: when you are tired, your body gets injured more. Sleep is a huge tool for managing that.”
Russell uses sleep data to modulate Taylor Fritz’s training loads in real time. After a five-hour match where Fritz’s sleep scores fall below the optimal range due to the physical toll, Russell and his team reduce the training session that follows, protecting the body rather than compounding the stress. “We tailor practices based on his quality of sleep,” Russell explains. “We see the sleep scores are not where we want them. We pull back. The goal is always to get those scores back into the optimal range, so we know the recovery is working.”
Coaching female athletes: The sleep science gap
Anton Dubrov raises a topic that receives little attention in mainstream sports science: the distinct sleep and recovery needs of female athletes, and how poorly understood they remain.
“Female athletes have been so underrated in recovery and training research. Most of the studied protocols have been on male athletes. Right now we are getting much more data on how female athletes recover, train, and eat, but we are still catching up.”
He points specifically to the menstrual cycle as something every coach working with female athletes needs to understand and plan around, not ignore.
“In the second phase of the cycle, body temperature increases. You have to be aware that the sleep environment should be cooler than usual to help with recovery. During a tournament you cannot change much, but you can adjust the environment. Better recovery and sleep help control the emotional and physical side much more during this sensitive period. All athletes are different and struggle in different ways. The best you can do is create an environment that helps them feel better.”
— Anton Dubrov, coach of Aryna Sabalenka
This is a reminder that sleep science, and recovery science more broadly, is not one-size-fits-all. Personalisation matters. And the data to support female athletes is, finally, beginning to catch up.
What the coaches agree on: five principles
Across three different athletes, three different tours, and three different coaching philosophies, the same principles emerge repeatedly:
- Consistency beats perfection: Dubrov recommends anchoring to a consistent wake-up time above all else. Naps between sessions are valuable. Sleeping in is less important than sleeping regularly.
- The environment is controllable, and underinvested in: All three coaches emphasise controlling what you can: darkness, temperature, noise, pillow. The room is your recovery tool before anything else.
- Cool is better: The science is unambiguous. A cool room 18°C to 20°C (64ºF – 68ºF) for most, promotes deeper, more restorative sleep. Temperature is the single most impactful environmental variable.
- Sleep beats late-night treatment: When time is short, getting to bed earlier wins against extending recovery protocols. The body does its real repair work during sleep, not on the physio table.
- Data informs, but decisions are still human: Russell uses Eight Sleep’s sleep fitness scores to reduce training loads. Dubrov distinguishes between data as passive observation versus active intervention. The number tells you something; what you do with it is the coaching.
The night before changes everything
There is no grand tactical secret to what Russell, Delgado, and Dubrov are doing. They are taking something that most athletes treat as passive, sleep, and making it deliberate, measurable, and optimised. They are treating the hours between matches as seriously as the hours on court.
The implication for anyone who trains seriously, regardless of whether they play tennis, compete at any level, or simply want to perform better every day, is straightforward. It is the training session that makes everything else work. Sleep is not what you do when training stops. It is where training happens.
Meet the coaches
Anton Dubrov — Coach of Aryna Sabalenka
Anton Dubrov works with world number one Aryna Sabalenka, the most dominant women’s player of the current era, with multiple Grand Slam titles to her name. Dubrov is on the road 35 to 40 weeks a year, navigating the relentless calendar of the WTA tour across every climate and time zone. He is a deeply pragmatic thinker about recovery: he does not see sleep technology as a nice-to-have, but as an active intervention tool. He also brings a unique perspective on how sleep science applies differently to female athletes, a topic he considers vastly underrepresented in the coaching world.
Michael Russell — Coach of Taylor Fritz
Michael Russell is one of the most respected voices in American tennis. A former ATP professional turned coach, he has guided Taylor Fritz, currently ranked in the top five in the world, through deep Grand Slam runs, including the US Open final. Russell understands the physical demands of professional tennis from the inside: the hours on court, the back-to-back matches, the different surfaces. He approaches sleep with the same analytical rigour he brings to every other part of Taylor’s preparation.
James Delgado
Jamie Delgado has been coaching on the ATP and WTA tours for over a decade. He is perhaps best known for his six-year partnership with Andy Murray, a period that included Wimbledon glory, an ATP Finals title, and a year-end world number one ranking. He has recently been working with Jack Draper, the top British player and one of the most exciting young athletes in the game. Jamie speaks with unusual honesty about his own relationship with sleep: historically a poor sleeper, he has lived through the toll that high-pressure coaching takes on the body, and he brings that personal experience to how he thinks about recovery for the athletes he works with.
Frequently Asked Questions
How much sleep do elite tennis players need?
Michael Russell, coach of Taylor Fritz, targets a minimum of nine hours per night. During Grand Slams and heavy tournament periods — especially after physically demanding five-set matches — more may be needed. Quality of sleep (deep sleep and REM stages) matters as much as total duration.
What is the ideal sleep temperature for athletes?
Anton Dubrov, coach of Aryna Sabalenka, recommends approximately 68°F (19°C) as an optimal starting point. He cites research showing that slightly cooler temperatures — even down to 61ºF (16ºC) for some athletes — further support deep sleep and recovery. The principle: a cool bed allows the body’s core temperature to drop, which is a biological signal for deep, restorative sleep.
Is sleep more important than other recovery tools like ice baths or massage?
When time is limited after a late match, all three coaches prioritise sleep over additional treatment. James Delgado and Michael Russell both describe situations where they shortened physio sessions to allow their athletes to get to bed earlier. Sleep is when the body performs most of its physiological repair — other recovery tools complement it, but do not replace it.
How does poor sleep affect on-court performance?
According to the coaches: energy drops, reaction time slows, alertness falls, and the ability to absorb coaching instructions reduces. Delgado notes that poor sleep leads to “average sessions” — training time lost that cannot be recovered. Russell observes both mental and emotional fatigue. Dubrov links chronic under-recovery to increased injury risk, noting that in tournament play, cumulative fatigue compounds faster than most coaches anticipate.
How do tennis players manage sleep while travelling?
Consistency is the key strategy. Dubrov travels with the same pillow, requests air-conditioned rooms on high floors, and uses white noise apps and blackout curtains. All three coaches emphasise that the goal is recreating the same sleep environment wherever possible — the body responds well to routine, even while the location changes. Russell also factors jet lag into Taylor Fritz’s training schedule, ensuring that recovery time is built in after long-haul travel.
Does sleep affect injury prevention in tennis?
Yes, significantly. Delgado’s team monitors fatigue levels and has identified direct links between poor sleep and his injury patterns. Russell adjusts training loads based on Fritz’s sleep scores, pulling back when recovery is below optimal to avoid placing additional stress on a body that has not fully repaired. Both approaches treat sleep as a leading indicator — not a lagging one.
