Allen’s training approach was to divide his year into three phases (Allen 1996 table 6.27). The first phase would begin in January after two months of rest in November and December following the Hawaiian Ironman Triathlon, which is contested on the first Saturday in October closest to the appearance of the new moon

During the first phase, his Patience Phase, Allen combined aerobic training with weight training. This period would last three months. During this time, he would not train at a heart rate in excess of that allowed by the Maffetone formula, which was about 150 beats per minute during the last five years of his career. During this period of training, he was swimming 21 km per week, cycling 500 km per week, and running for 6 hours (approximately 90 km) per week. Thus, his total endurance training time was about 27 hours per week during this period. Allen would also undertake two strength training workouts each week but would always leave at least two clays between sessions.

To monitor his progress, Allen would complete an 8-km run at his maximal allowed aerobic heart rate of about 150 beats per minute. During his Patience Phase his average pace when running at that heart rate would fall progressively. When he first started training according to the Maffetone approach, his aerobic pace during this test was 4:05 per km. During this phase, Allen would expect his running speed at his aerobic heart rate to fall by about 3 to 4 seconds per km per week.

When Allen retired in 1995, his aerobic pace had improved to 3:19 per km, as the result of a steady progression during his entire career. For physiologists used to reporting human training studies lasting a few months, this is a remarkable finding. It shows that the human body may continue to adapt for 10 or more years to the form of prolonged, intensive training undertaken by Allen.

He would terminate his Patience Phase when either

-his speed during the 8-km aerobic run was no longer improving or was, in fact, deteriorating, indicating that he was no longer adapting to the aerobic training, or

-he was about five or six weeks before the first race of the season, usually a standard distance triathlon.

During the second phase of his training, the Speed-Work Phase, Allen reduced his training slightly but added two speed sessions, one on the bicycle and one running fartlek session. As a result, his training volume during this period included swimming 18.5 km per week, cycling 480 km per week, and running 8 hours per week.

Allen advised that when he was young, presumably under 30, he could complete 10 to 12 weeks of this type of training. As he aged, he found it more difficult to maintain this volume of training for as long. At age 37, he could maintain this training for six weeks. He predicts this would be reduced to five for athletes over 40 and to none for athletes over 50.

At the end of the previous phase, Allen would judge whether he had reaped all the benefit from this training schedule when his running pace at his aerobic heart rate plateaued. He wrote that

“the key is to watch for a slowing of your pace at your maximum aerobic heart rate. When this happens, its time to go back to your base-building phase….It’s very subtle, but if your heart rate starts going up for a given effort in workouts, you know that you’re on the edge—just resting won’t help; you have to modify your training.” (Allen 1996b, p. 92)

Allen notes that many other athletes would probably try to train through this plateau in an attempt to reach an illusive higher level of fitness, But Allen stresses that this will fail, as continuing to train when the body’s adaptation has plateaued will lead only to mental burnout, overtraining, injury, and a subpar performance on race day. When this happens, Allen’s advice is, “If you`re burned out, put a big ‘R’ for rest in your training diary, close it and put it away, Rather go and play” (Allen 1996b, p. 92).

As he has grown older and is therefore unable to sustain this training phase for as long as before, he spends a few weeks of recuperation training, perhaps even including a full week of rest, in July and early August. During this period he does no speed training but reverts to training that does not elevate his heart rate above 150 beats per minute.

Eight weeks before the Hawaiian Ironman, Allen begins the Push Phase of his training. This consists of four hard weeks of training and a four-week taper. During this time, Allen does not race at all. This period of training is, in my view, the most taxing training ever recorded by any modern human athlete, exceeding even that of the Kenyans (table 6,28). During his peak training week, Allen will swim 28 km (8 hours), cycle approximately 800 km (22 hours), and run for a further 8 hours, for a total training time of 38 hours, equivalent to the hours many of us spend at work during a five-day working week. To develop both speed and endurance, Allen reverts to doing long intervals of up to 20 minutes in both cycling and running during his long rides or runs.

During his four-week taper period, Allen progressively reduces his cycling distance by 160 km per week so that in the final week of his taper, which includes the distance cycled during the Ironman, he cycles only 240 km. This means that he only cycles 60 km in the final six days before the Ironman. He reduces his weekly running distance by 24 km per week and only runs 16 km in the last six days before the Ironman.

-The key workouts each week during the Speed-Work and Push Phases are the two long-distance and two speed workouts, one each cycling and running. All training is built around those workouts.

-During the Speed-Work Phase, only one or preferably two, but certainly no more, sessions should be set aside for all-out speed training.

-His longest run before the Ironman was always five weeks before the race, and his longest cycle, four weeks before. His toughest speed session was three weeks before the race, during the tapering period.

-For his long runs he would begin at 1 hour and then increase in stepped fashion by 10 minutes every second week, dropping back to the duration of the run two weeks earlier in the intervening week. Thus, the duration of the first seven consecutive long runs would be 60, 70, 60, 80, 70, 90, 80 minutes. After 15 weeks, this would increase to the 150-minute  long runs that Allen maintained during the Speed-Work and Push Phases.

-In a discussion I had with him in Pajulahti, Finland, Allen added that the key to his longevity was the three months of gentle aerobic training in the Patience Phase. His belief is that once you begin speed training, the body enters a hyped-up state that wears you down, as you are unable to sleep properly and recover adequately during this period. Thus, in his opinion, intensive training produces a cumulative fatiguing effect, which is not due solely to the actual training performed but also to a residual effect that acts during the recovery period between training sessions.