High-intensity interval training is a proven and time efficient method of improving endurance fitness. With that in mind, Andrew Hamilton looks at some brand new research on how it could be made even more effective MORE
Periodisation: how to vary your training programme through the year for optimum results
If you want to improve your performance, you can’t train in the same way all the time. Owen Anderson explains why and comes up with periodisation guidelines
If you want to improve your performance, you can’t train in the same way all the time; if you did, your body would simply adapt to the training, your fitness would settle at a fixed level and you could continue to train vigorously without making the slightest improvement. Hoping to perform better with an unchanging training programme is like expecting to become highly skilled at calculus while working solely on the simple equations encountered in first-year algebra.Does that seem obvious? It should; nevertheless, many athletes follow the same basic training plan, month after month, year after year, in the expectation of PBs. A typical weekly programme for an incredible number of endurance runners for much of the training year consists of one session of speed work, a tempo run or hill effort and a long run at the weekend. When their performances don’t improve significantly, they scratch their heads and wonder what is wrong.
One of the key things that is wrong, of course, is that they have failed to periodise their training in a productive way. Periodisation in this context means changes in the volume, intensity and frequency of training over time; it also encompasses changes in the basic structure of training over time.
The notion that proper periodisation of training is necessary for the achievement of peak performance originated with the ancient Greeks, who used basic periodised training schemes to prepare their athletes for the Olympics. For example, the legendary Milo of Croton varied only the intensity of his training, lifting a bull-calf on a daily basis until it was fully grown, at which point Milo was able to lug the adult bull around the Olympic stadium.
Another legendary figure Galen (AD 129-199), who became ‘doctor to the gladiators’ in Rome, was the first person to write at length about periodisation. He believed there were various types of exercise which needed to be blended in order to enhance performance; and he classified exercises into those which exercised the muscles without violent movement (digging and weightlifting, for example), quick exertions which promoted activity (ball play and a form of gymnastics), and ‘violent’ exercises, which might today be called ‘plyometrics’.
After Galen’s death, periodisation went through a long-ish ‘down period’, but the philosophy of changing training as a function of time experienced a small rebirth in the 1950s and began to come into full bloom in the 1960s and early 1970s. This revival was due, at least in part, to some groundbreaking research by the noted physiologist Hans Selye, who ultimately formulated what he called the ‘general-adaptation syndrome’.
According to this theory, physiological systems respond to any changes they experience in ways which allow the ‘stressors’ (things in the environment that are different and challenging) to be coped with more readily. Once the adaptive response is completed, however, the physiological systems stop changing and new stressors are required to produce further adaptation. If stressors are uniquely and properly periodised, an organism can continue adapting and – in theory – continue improving its overall physical capabilities until its absolute upper limit of adaptation is reached.
Periodisation does work
Basic scientific research reveals that periodisation does work, in that it produces better improvements in performance than non-periodised training programmes. In the first periodisation study ever published, college-age males completed either a non-periodised strengthening programme of 3×6 sets or a periodised programme, which progressed from high volume (lots of reps) and low intensity (low resistance) to lower volume and higher intensity over a six-week period. After six weeks, the periodised trainees were appreciably superior to the non-periodised group across a number of measures, including parallel back squatting strength, lean body mass and vertical jump power. A major problem with this study, however, was that total volume of training was greater in the periodised group, and thus periodisation was not the only variable.
In an outstanding follow-up study, which partly overcame this problem, Darryn Willoughby of Texas A&M University divided 92 weight-trained male college students into four equal groups, undergoing differing 16-week training programmes using just bench press and parallel back squat exercises(3). At the beginning of the study period, the members of all four groups showed equivalent strength in these two exercises.
The work programmes varied as follows:
- Group 1 trained with five sets of 10 reps of each exercise per workout three times per week, with three-minute recoveries between sets and with resistance set at 79% of the one-repetition maximum (1-RM, the maximum weight which could be lifted one – and only one – time). This relative intensity was kept constant throughout the study, although the absolute intensity (actual amount of resistance) could increase if the 1-RM increased (1-RM being determined for each exercise at four-weekly intervals). Thus, this programme involved little periodisation;
- Group 2 trained with 6×8 reps per workout thrice weekly, with the relative intensity set at 83% of the 1-RM for each exercise. As for Group 1, relative intensity remained constant, although absolute intensity could rise if 1-RM burgeoned during the monthly strength tests;
- Group 3 enjoyed a more generous periodisation programme, hitting 5×10 reps at 79% of 1-RM per workout for four weeks, 4×8 reps at 83% of 1-RM for the next four weeks, 3×6 reps at 88% of 1-RM for another four weeks, then 3×4 reps at 92% of 1-RM over the final month. For this group, relative intensity (% of 1-RM), absolute intensity (actual amount of resistance) and training volume (number of reps completed) all varied during the study, and the overall protocol resembled a classic periodised plan, with training volume decreasing over time while training intensity advanced. During the second half of the study, the members of this group were lifting significantly less weight per week than those in groups 1 and 2, but were working considerably more intensely (lifting more weight per rep). For example, during weeks 8-16, groups 1 and 2 were bench-pressing over 12,000kg per week, compared with just 3,400-4,800kg for Group 3. Note, though, that for all three groups training frequency was identical at three workouts per week.
- Group 4 (the control group) had it easy, playing badminton throughout the 16-week period and engaging in no parallel squat or bench press training. They did, however, have tests for 1-RM at four weekly intervals, just like the strength-training athletes.
After 16 weeks, members of group 3 were stronger in both bench press and parallel squat than any of the other groups. How should this finding be interpreted? Dr. Willoughby suggested the key take-home lesson that variation is an important component of training programmes; but we can go a bit deeper than that. Basically, intensity tends to be a more potent producer of fitness than mere volume or frequency of training. And athletes who periodise their training so that the average intensity of training increases over time should triumph over those whose training intensity remains flat. In this study, intensity was raised by giving strength-trainers higher relative and absolute resistances, but the principle would also work for endurance athletes. Cyclists, for example, could gradually increase average training intensity by pedalling faster during quality workouts, or boosting the number of quality sessions conducted each week.
So, periodisation which pushes quality appears to be a good thing. One major problem, however, is that there are so many different types of quality workouts to consider. Endurance athletes, for example, might choose to train at anything between 85 and 130% of VO2max, and any such effort could be considered a quality exertion. Power-type athletes might select plyometric sessions, general strengthening drills, movement-specific strength training or classic upper- and lower-body strengthening efforts.
Training should be goal-oriented
As noted strength expert Steven Fleck points out, strength trainers can vary the number of sets for each exercise, the number of repetitions per set, the actual exercises performed, the number of exercises per training session, the rest periods between sets and exercises, the resistance used with each set, the muscle action performed (eccentric, concentric or isometric), and the number of training sessions completed per day and per week. How should these possibilities be brought together in a cohesive plan?
It is important to remember, too, that periodisation should always be goal-oriented, so that fitness increases steadily during the training period and reaches a maximum reasonably in advance of the major event of the season or year. In addition, the endurance athlete needs to periodise workouts so that vVO2max, lactate threshold, economy of movement, event-specific strength, power and event-specific preparation are optimised. How can all this be accomplished? With four key variables to consider (intensity and type of workout, volume and frequency) and an incredibly wide range of values associated with each variable, athletes have almost limitless options. How does one pick the right periodisation system?
This is a question that science has found it hard to answer, and outstanding, practical, well-controlled scientific studies on periodisation are few and far between. This may seem a bit surprising, given the general popularity of periodisation, but one of the basic problems is that exercise scientists often feel that they need to limit the length of their research studies to 12 weeks or so and it is very difficult to complete a comprehensive periodisation study in such a short period.
Large fitness gains take time
When we examine the differences in training between athletes who are consistently successful and those who perform inconsistently, we are most interested not in what the high-performing athletes have done over the past week or even the past month or two, but in how they have organised their training over at least the last year. Proper periodisation means coordinating training optimally over extended periods of time – long enough to make large gains in fitness and prepare properly for major competitions.
Another obstacle to periodisation research is that it can be hard to get a group of athletes to adhere to a specific training programme for a year or more at a time; many athletes will drop out, others will not follow the prescribed training very closely and some will get injured. For an exercise researcher, embarking on a long-term periodisation project is a pretty risky thing to do because the whole thing may blow up in his or her face after many months of hard work.
As a result, research scientists have tended to bite off small parts of the periodisation puzzle. For example, one of the questions they have been most interested in is whether ‘linear’ periodisation is preferable to the ‘undulating’ variety. The resulting research is actually fairly interesting, especially since many athletes follow some form of the linear periodisation plan.
With linear periodisation, athletes generally build up their total volume of training in a linear way and then gradually (linearly) decrease volume while steadily increasing training intensity (the basic approach followed by the strength-trained athletes in the Texas study mentioned above). Generally, training volume reaches its nadir and training intensity its apex shortly before the most important competition of the overall training cycle, which is commonly pegged at six or 12 months; (we won’t discuss macrocycles, mesocycles and microcycles in this article because such discussions are generally as useful to athletes as discourses about motorcycles)!
Although linear periodisation is appealing to athletes, there is nothing particularly beneficial about it from a scientific standpoint. The underlying philosophy is that athletes need to build up some level of strength and endurance before they attempt high-intensity training; thus, they work on boosting their volume of training before initiating high-quality work.
The problem with this argument, however, is that the basic premise is wrong: athletes are capable of carrying out reasonable amounts of intense training early in the training year, and there is no real reason why they should not do so. In fact, since competition requires intense effort, since efficiency during intense work can only be developed during intense exercise and since intense work is the most potent advancer of fitness, it would seem logical to introduce high-quality training as early as possible in the overall training schedule.
The less popular undulating periodisation is marked by fairly frequent alterations in the intensity and volume of training. Instead of changing training over a period of months, undulating training makes major changes on a weekly or even daily basis. Strength-trainers, for example, might move from high-volume, low-intensity work to low-volume, high-intensity lifting within the same week. A typical example of this would be the completion of sets of 12-15 repetitions maxima on Monday, 8-10 on Wednesday and just 3-5 on Friday; (the word ‘maxima’ here refers to using a resistance with which one could complete no more than the stated number of reps in any one set).
Undulating v linear training
With undulating periodisation, the so-called phases of training tend to be much shorter than with the linear variety. Exercise physiologists and some coaches have been attracted to undulating periodisation at least partly because of the belief that frequent changes in training stimuli are highly conducive to gains in fitness. One physiological basis for this principle is that with undulating periodisation the nervous system is forced to adapt to a wide variety of situations, including the elicitation of tremendous amounts of force (when resistance is high) and very rapid rates of force application (when resistance is low and reps are completed quickly). In theory, when these various stimuli are presented together in close temporal proximity, the neuromuscular system might adapt unusually quickly and develop an enhanced ability to respond with great force and speed.
Does undulating periodisation really work better than the classic linear model? To find out, researchers from Arizona State University divided 20 strength-trained men into two equal groups for a 12-week training programme. Both groups performed abdominal crunches (3-4 sets of 15-25 repetitions), biceps curls (3 sets at 8-12 rep max) and lat pull-downs (3 sets at 8-12rep max) three times a week. Both groups also trained intensely with two key exercises – the bench press and the leg press – but the performance of these exercises was completed in either a linear-periodised or undulating-periodised way. For the bench press and leg press, the linear-periodisation (LP) group performed 3 sets per workout at an intensity of 8-rep max for the first four weeks of the study, 6-rep max for the next four weeks and 4-rep max for the remainder of the study – a classic linear pattern.
The other group used daily undulating periodisation (DUP), with workout patterns changing from day to day. For this group, the first session of each week of the 12-week programme consisted of 3 sets at 8-rep max, the second workout of 3 sets at 6-rep max and the third of 3 sets at 4-rep max. As you can see, training volume and intensity were altered in different ways for the two groups, but total volume and intensity were absolutely equivalent over the study period.
Both LP and DUP groups increased strength significantly in both the leg and bench presses over the 12 weeks, but the gains were significantly greater for the DUP group. Specifically, this group enhanced bench press strength by 29%, compared with 14% for the LP athletes, and boosted leg-press strength by 56%, compared with just 26% for the LP pressers.
What was going on? Why did the DUP programme have such a pronounced effect on strength gain? The researchers suggest that the nervous system may be the key player involved in producing the differing gains in strength. In theory, the nervous system may adapt less readily to training if it is exposed to a single type of training for an extended period of time (such as the four-week blocks of time used in the LP plan in this research) and might respond more effectively if the volume and intensity of training are adjusted frequently (as they were with DUP).
As implied earlier, pointing a finger at the nervous system is a reasonable thing to do, and is supported by the fact that in this study there were no significant changes in body composition or muscle circumference in the two groups over the 12-week period! Thus, the greater strength displayed by the DUP group was not due to thicker muscles or leaner physiques but must have been related to the way the nervous system was controlling the sinews.
A number of practical pointers emerge from both this study and the Texas investigation mentioned earlier. First, it seems obvious that athletes should probably not plan extended ‘blocks’ of training (lasting several weeks or longer) during which workouts are relatively uniform, since fitness progression is likely to be slower than with more variable training. Thus, the familiar pattern of speed on Tuesday, tempo training on Thursday and a long effort on the weekend may make for a nice training week, but is not a building block for a great training month and is a frankly crumbly foundation for a six-month preparation for a major event.
It also makes sense for athletes to diverge from traditional patterns of ‘base-building’ and ‘recoverytraining’. At the beginning of a training year, many athletes try to lay a foundation for what lies ahead by working at low-to-moderate intensities while gradually building up their total volume of training. During this base-building period, the quality of training is generally low, in part because it is believed that the musculoskeletal system is not yet strong enough to handle higher-intensity work. There is really little justification for this practice, however: as long as intense efforts are attempted reasonably, the risk of injury should be no greater than it is with augmentations in volume.
Variety in base-building and recovery
In addition, since the whole idea of training is to progressively and steadily move one’s fitness to higher and higher levels, it makes little sense to devote significant blocks of time to exertions which will fail to do this or will do it more slowly than other forms of training. Thus, varied training, with an adequate inclusion of quality, is preferable to uniform, mediocre-intensity training during base-building periods.
The avoidance of uniform training is also important during recovery periods (i.e. during the month after a major competition or a week of ‘easy’ training within a strenuous training period). However, recovering is not the same as training easily all the time; one can still recover while using a varied programme into which some quality has been inserted.
While these pointers about periodisation should help you, bear in mind that real knowledge about the proper periodisation of training is extremely ‘lightweight’ at present: not only have most periodisation studies been constrained by time (and, to some extent, by the researchers’ imaginations) but no studies at all have been carried out with female athletes, veterans or children, while the periodisation models used in research projects to date have been quite limited.
Periodisation work has also been biased towards strength trainers, with little emphasis on endurance athletes. In one of the very few studies in which endurance activity was even mentioned, an effort was made to assess the impact of various types of strength training on endurance performance. Three different strength-training programmes were compared, one featuring one set at 8-12-RM per workout, the second including three sets at 10-RM and the third consisting of a periodised plan for advancing strength and power. Seven different exercises were used in each programme.
With the periodised plan, volume steadily decreased and intensity was augmented from 10-RM to 3-RM over the course of the study. After seven weeks, the researchers measured resistance to fatigue during back squatting, and endurance while cycling at an intensity of 265 watts. As it turned out, only the 3×10 and periodised groups displayed improvements in both tests. In addition, improvements in cycling endurance time tended to be greatest in the periodised group.
So what is the bottom line on periodisation? As the renowned running coach Arthur Lydiard once said: ‘Athletes tend to repeat their basic training patterns over and over again, yet with each repetition of the basic plan they expect different (ie better) results.’ A properly periodised programme prevents the performance plateaus which are inevitable with over-repetitive training. As you construct your overall programme, you should be certain to include variety in your training, not just from month to month but also from week to week and even from day to day; the limited periodisation research which is available suggests that such variety can be conducive to fitness gains.
You should also be sure to include in your programme workouts which have the greatest chance of optimising the physiological variables that are crucial for success in your event, and you should ‘mix’ such workouts over time instead of hammering away at just two or three different types of exertion.
Skill-strength periodisation may be the best way forward
One of the interesting periodisation schemes which will be looked at closely in the future is ‘skill-strength periodisation’ (SSP). Once the linchpin of the former Soviet Union’s track-and-field teams’ Olympic preparations, SSP requires athletes to spend an extensive amount of time perfecting their technical skills during the preparatory phase of training before embarking on the development of strength, power and endurance. The idea is that once athletes are skilled (ie once they are technically proficient jumpers, stroke-perfect swimmers or economical runners), they can then use their increasing strength to boost performance optimally, because the increased strength that they subsequently gain is not ‘wasted’ on inefficient movements but channelled directly into proper patterns of motion. Of course, this is the opposite of many traditional schemes, which mindlessly crank up the volume of training as the first step in the periodised plan in order to ‘build strength’.
As you might expect, no carefully-controlled published scientific research has ever contrasted skill-strength periodisation with the classic linear model, but SSP is attractive for logical reasons. With SSP, swimmers, for example, might spend months perfecting their strokes before they ever bothered with high-volume or high-intensity swimming; since strength is extremely movement-specific, the swimmers could then be assured that the gains in strength achieved during subsequent high-volume training would be specific to the best-possible movements – the ones which could produce the fastest and most efficient swimming.
Similarly, runners might spend many months developing outstandingly efficient running form before worrying about hiking their volume and intensity of training. Even though running is not considered a ‘skill sport’, early enhancement of efficiency could help runners avoid the ‘hard-wiring’ of inefficient running patterns (which might develop during 100-mile weeks characterised by sloppy form) and might also foster higher-quality training during subsequent periods of high volume and/or intensity.