Sparring is the third and more traditional element of Graham's regime. All boxers spar but the volume and intensity differs. Sheffield trainer Brendan Ingle is famous for not allowing any head punches. Graham, like the majority of trainers, allows them but is careful to limit sparring sessions for health and fitness reasons. "You shouldn't have a war in the gym but you have to get used to taking a shot," says Hatton, who sometimes spars with his brother Matthew. "Some fighters do 12 rounds sparring every day but to me that's taking too much out of your body."
To simulate boxing matches Hatton's training is broken down into three-minute rounds with a minute's rest in between. However, he doesn't do an entire three minutes on either belt or bar: he alternates between the two exercises. So if he starts with a minute on the bar, he then goes straight into a minute on the belt followed immediately by another minute on bar. That's one round. He rests for a minute then does a full three minutes sparring. That's another round. Rest again. His third round is a minute each on belt-bar-belt, and so on. In the eight weeks before a fight he builds up the rounds from eight to 12, before concluding with one phenomenal 15-round workout.
Tuesdays and Thursdays are for technique, giving the body time to recover. Hatton does eight rounds on the punch bag plus 20 minutes on the pads. He may also throw in some speedball work or skipping.
Roadwork is an everyday affair. On weekday evenings, and weekend afternoons Hatton runs about six miles on the steep streets around his edge-of-Peak District home. Roadwork is an essential ingredient of a boxer's conditioning. "Because we work so hard in the gym, our roadwork tends to be steady," he says.
With so much emphasis on stamina you might be surprised to discover how big a part weight training plays in the Hatton regime - and some old-timers would be positively horrified to discover his workouts are co-ordinated by a bodybuilding expert.
Weight training for boxers is one of the sport's oldest taboos. Even today, a few grizzled old trainers insist that fighters should never touch weights because it makes them slow and muscle-bound.
Graham, whose camp also includes WBU middleweight champion Anthony Farnell, featherweight prospect Michael Gomez and Hatton's promising younger brother Matthew, considers weight training to be as important a part of fight preparations as pad work and skipping. "If a fighter came to me and refused to train with weights I wouldn't be interested in taking them on," he says.
Graham's respect for the iron stems from his late brother, who was a bodybuilder. "I've always said to my boxers that bodybuilders are so scientific, they can do incredible things with their bodies," he says. "We can learn so much from them about training and nutrition. As for weights slowing you down you only have to look at sprinters to see what nonsense that is."
A ghost-white 10 stone, Hatton hardly looks like a man who spends hours blasting his pecs or building up his legs. But that's precisely the point: he isn't in the gym to add unnecessary bulk. He's there to supplement his ring work with strength and power.
Hatton weight trains four days a week, usually after his ring work, for 20 minutes per body part. He trains two muscle groups each session, alternating between quads and calves, chest and biceps, back and hamstrings and shoulders and triceps.
Kayes, who owns Betta Bodies gym in Manchester where the Phoenix camp is based, says: "My job is to try and build his strength without adding too much extra size with the minimum risk of injury and without sapping too much of his energy levels."
Hatton, who can bench press 160 pounds, is convinced it's working. "I've always done weights but moving to Betta Bodies with Kerry has taken it to another level," he says. "With the amount of punching and speed work we do it will never slow me down: it will just make me punch harder."
Three weeks before fight night, Hatton is cooking. At this point his training steps up the final notch. He begins a hyper-intensive fortnight of 12 rounds on the bar, belt and sparring five days a week. On the Friday of the second week, eight days before the fight, comes his incredible final workout, which has become legendary in boxing circles. To the awe of onlookers, Hatton does a full 15-rounds on the body belt, hitting his trainer with a chilling intensity while Graham, shielded from the full force of his blows, keeps coming forward to pressure him into working harder.
Earnie Shavers, the American heavyweight who floored Muhammad Ali and now lives in Britain, is among those who have made the journey to Betta Bodies to witness it. "Word has got out," says Hatton. "The gym is always packed solid for the final session."
By now Hatton is shattered. Training is done. The final week is about resting and making the weight without having to diet too drastically, which can weaken a fighter catastrophically. This is where Kayes comes in again, applying bodybuilding principles to boxing.
"Boxers traditionally are feast or famine," says Kayes. "I have explained to them that eating small and regular meals will speed their metabolism up. I've also given them a baseline of nutrition so they can cut back from something when they need to lose weight and made them aware of the importance of an after workout recovery drink plus vitamins and minerals."
"Kerry knows how the body works and he applies that to boxing," says Hatton. "I can say to him 'I feel a bit fatigued today' and he can recommend changes to my diet. At the top level little things like that make the difference between winning and losing."
'Train hard, win easy' is a popular saying among African distance runners. In boxing, when a guy is attempting to knock you senseless, nothing comes easy but the intensity of Hatton's training means that when fight night arrives he has a Plan B. "In boxing you can't always rely on knocking someone out," he says. "You have to be prepared for long fights and my conditioning enables me to sustain the pressure from beginning to end," he says.
Hatton is honest enough to admit that his 'let's have it' style means he is unlikely to still be fighting in five years. "I go hell for leather from bell to bell but it's playing with fire really," he says. "Every fight is a war so I don't think I'm destined for a long career. Because of the pressure I put on opponents I take punches and I take chances. It's very exciting for spectators."