Is HIT (High Intensity Training) Useful for Swimmers? Part I

http://www.swimmingscience.net/2015/10/is-hit-high-intensity-training-useful-for-swimmers.html

Swimming Methodology

Sports training methodology is characterized primarily by the intensity, duration and frequency of exercise stimuli.  A combination of practical experience and scientific evidence, combined with an increasingly important and adequate analysis of recoveries, has been shown to be a prerequisite for an effective workout. 

A trainer who relies on his experience knows that, although have obtained successful results with an athlete, it is difficult to duplicate the same scheme for a second or third athlete. 

Similarly, an expert in physiology, scientific research or evidence-based methodologies is not always able to identify an athlete’s real needs from the field, or from the athlete's feedback.

Therefore, in reality, it is the combination of a trainer and an exercise physiologist that best allows an athlete’s experience to accumulate progressively and always to continue increasing in the future, especially when athletes arrive at the level at which their “trainability” becomes increasingly reduced, at which point they would then need to study, test and investigate the areas in which they could still make improvements to their performance.

Training of quantity, quality and intensity

This combination sometimes requires a precise recipe, which is distinguished by a coach’s choices, based on the metabolic needs of the specific discipline. 

The swimming competitions range between 22 seconds and 15 minutes in length, time intervals whose metabolic demands are mainly covered by both anaerobic and aerobic metabolism.

Another classification (Chamari, 2015) recommends the use of terminology related to the duration of the exercise:

1. “explosive effort”: up to six seconds, with the use of phosphagen pathway;
2. “high intensity effort": from six seconds to one minute, in which the glycolytic pathway is predominant; and
3. “intensive long-term effort”: for all activities lasting over one minute, involving the progressive prioritization of oxidative phyosphorylation 

Over the years, numerous scientific papers have analysed the effects of training methods, mostly those used in swimming (based mainly on volumes), to the point where progressive choices and their implementation is increasingly based on scientific evidence. 

A critical view was put forward by researchers from Indiana University (Stager, 2014), who had studied how the American team used “methodologies based [on those of] Doc Counsilman”, and that between the '60s and the '80s they have experienced a progressive decrease in volumes, up to 2.8 times lower by the end of the decade. Recent studies have demonstrated, especially in other individual cyclic sports (running, cycling), that an approach more geared to greater intensity could have a positive impact on the physiological responses and performance of the athlete (Bechheit, 2013).

Does using science lead to better results?

Addressing this aspect in terms of a range of degrees of “faith” is definitely an appropriate approach. Some evidence for this, which is useful for analysis, derives from the fact that France won 12 medals at an international level (i.e., Olympics and world competitions) between 1984 and a further 66 between 1998 and 2013 (Hellard, 2014). The choices they made over the years were only the result of careful selection, evidence-based, and progressively implemented by national coaches and in regional technical courses.

Elsewhere in the world, there are well-known cases such as the Australian Institute of Sport leading the research applied to sport and, as recently happened with their adaptation of circadian rhythms for the Rio Olympics, the entire national swimming team promptly responded by showing a strong motivation.

Team GB increasingly formulates athletes’ schedules through collaboration at a scientific level, by putting into action the big scheme of work carried out by the UK Olympic Committee for the quadrennium previous to the London Olympics, in which changes were made to the directions of all national sports, on the basis of scientific evidence. This is a route that is currently well delineated across the world: highly experienced coaches who, thanks to the unlimited scientific resources available, are now able to get internationally outstanding results, keeping in mind that the inappropriate use of knowledge or technology does not necessarily mean that you are doing “science” or using a scientific method.

Training based on scientific knowledge, or “evidence-based practice” (EPB), can be defined as “the conscientious, explicit and judicious use of the best evidence to make decisions. It means integrating individual experience with the best external evidence derived from systematic research” (Sackett et al., 1996).

This particular mode of training, EPB, is opposed to the methods of the past —which will increasingly tend to disappear in the future—such as training and beliefs based on pseudoscience, and belief-based coaching (Rushall, 2009).

Which types of scientific contribution can be adopted in swimming?

As anticipated, most scientific research has been conducted by studying adaptations in athletes from other sports. Leaving aside the specific situation is a must, considering that cyclic sports are closer to the individual performance model of the modern swimmer. 

The triathlon itself has shown that the combination of running and cycling workouts for swimming is not contradictory, as was thought in the past, but that it can also produce improved effects in swimming performance, and vice versa.

The fact that high-level swimmers successfully implement methods derived from the triathlon has long been known, and the results of some elite athletes are an example that should not be neglected.

The use of volumes in swimming training was thought of as only useful for the construction of the athlete in terms of his/her high-volume aerobic fitness, and requests for this type of training were made mainly in the early stages of preparation. Now the possibilities that refer to this same energy availability are numerous and high-intensity intermittent training is certainly the most discussed and probably the most effective regime that can be implemented.

Already in the 1990s, it had been shown that a reduction of up to 50% of the volume of work (Costill, 1991) did not result in any decline in the physiological parameters of reference and performance of athletes. The sample of this study adopted, on the one hand, a model of constant intensity at high volumes of work (9,300m per day), while, on the other hand, a second group used more intensity at lower volumes (5,000m). 

The study of high-intensity intermittent training was widely diffused, thanks to a particular study of training (Tabata et al., 1996), which was originally developed for Olympic ice skaters. In this study, athletes were asked to apply an ultra-intense commitment (equal to 170% of VO2 max), followed by 10 seconds of recovery, to eight cycles developed within six weeks. The protocol consisted of four weekly sessions, with a fifth day of training at a constant speed. The results were respectable and opened up new horizons; the “Tabata” resulted not only in a 14% increase on VO2 max, compared with the control group at a constant rate with 10%, but also an increase of 28% of anaerobic capacity, which was totally absent in the control group. From this research, published in Medicine & Science in Sports & Exercise, the authors (Tabata et al., 1996) indicated that this increase was “one of the highest values ever recorded in exercise science”.

The evolution of high intensity training

The acronym HIT, which stands for “high-intensity interval training”, was conceived in opposition to both the traditional training method (constant speed) and steady state training (SST). Sometimes confused with other well-known forms of exercise in swimming (such as fartlek), high intensity training is a method of training heavily influenced by scientific evidence and is today one of the most effective means of improving metabolic and cardiorespiratory function. 

The HIT provides short/long periods of repetitive exercise, interspersed with high-intensity recovery periods.

It is believed that the ideal stimulus to elicit physiological actions (primarily in the cardiovascular system and metabolic systems, and to combat neuromuscular and skeletal disorders) (Fig. 1) is for athletes to spend at least several minutes per session in their “red zone”, which usually means operating at at least 90% of their maximal oxygen consumption (VO2 max). However, the coach’s goal here (and this is the main difference between the experience and the evidence) is not to define an a priori “speed estimated at VO2 max”, but rather to calculate and implement in practice the “time spent at VO2 max” (TVO2 max). From this, it follows that when it comes to time training "in the red zone", athletes will get the greatest benefit from a 10-minute TVO2 max, since longer periods spent at 90% VO2 max with a greater volume of mileage necessarily lead to deleterious performances

Benefits and considerations when applying high intensity training to swimming

a) HIT protocols, with long, short and sprint interval variants, and different recovery times, could allow the athlete to reach VO2 max if properly designed (Fig. 2).
b) Individual differences among athletes and among different high intensity training regimes should be considered, in order to respect in achieving 90% minimum of VO2 max.
c) Repeated sprints and other forms deemed “high speed” should also be appropriately modulated as part of high intensity training.
d) An HIT protocol designed for long or short ranges that have a higher relationship between active phase / recovery phase, and has a greater TVO2 max HIT sessions.
e) HIT protocols based on countless combinations are particularly effective when used at the same time, and are still deserving of further scientific study.
f) Attaching a training model to a high-level neuromuscular HIT protocol can lead to a progressive improvement of the benefits of a single HIT.

Implementing a workout based on the scientific evidence surrounding high intensity training means devising and implementing a programme that takes into account nine variables (Laursen, 2002), the manipulation of which may or may not contribute to obtaining the greatest benefits by facilitating an increase of the following: end- systolic volume, plasma volume, efficiency, heart rate, blood flow, oxidative enzymes, glycolytic enzymes, buffering capacity, sodium-potassium pump, etc.

In applying the methodology to the field, it is advisable to attempt to meet the criteria and reference variables without following pre-built tables, but by instead applying complex reasoning to the objectives of the competitive swimmers themselves, starting from an existing evaluation made at the beginning of the season.

The HIT variables are as follows: work intensity, duration, intensity and duration of recovery, work mode, number of repetitions, number of sets, and intensity and duration of recovery between sets (Fig. 3).

Among the practical considerations, it should be remembered that the TVO2 max is the key benchmark, i.e., the time during which the swimmer is “really” training in the “red zone”. Following the kinetics of VO2 (Robergs, 2014), it cannot be assumed that the swimmer will achieve 90% of VO2 max in the first repetition, if not for sessions of three to four minutes. The design of HIT for repetitions of greater intensity and recovery factors of shorter duration becomes a priority, in order to grant the athlete the ability to recover; however, sharing a new phase with an intense base VO2 value (significantly higher than the initial TVO2) is always higher (Billat, 2001). It is an important aspect of the mechanisms underlying the work/recovery that, with appropriate manipulations, they can improve blood flow to accelerate muscle recovery, accelerate the resynthesis of phosphocreatine, the buffer effect on H+ ion, muscle lactate oxidation, etc. 

These aspects of HIT have been valued mainly for their cardiovascular aspects; however, the more appropriate and advanced application of HIT to swimming provides further features relating to glycolysis and energy contribution: a particular neuromuscular training integration which is very important in sprinters (Buchheit, 2013).

Verification methods in the application of HIT to swimming

The translation of scientific evidence to the field is obviously problematic in a sport such as swimming, where the systematic verification of reference values (i.e., the time to VO2 max) is limited by the absence of low-cost technology that can be used in the pool. From this, however, you can still try to work by considering the effects of recovery (Balsom, 1992), using an objective analysis of travel times.

The aim of an high intensity training protocol is to maintain the level of intensity within the set parameters; in order to achieve this, and by recording all results on a spreadsheet, you can collect weekly feedback, remaining practical but in line with expectations, even though the journey times of the intense phase may tend to remain constant or, as we would expect in the first few weeks, experience a rapid increase (Fig. 4). This approach is maintained mainly because the active recovery phase must always be equal in terms of intensity and duration.

Application

High intensity training is a complex method, and is certainly the workout method that has been most investigated across the world over the past decade. Knowledge of the systems, benefits and biochemical fundamentals that underlie the method is an integral part of its implementation.

It is therefore our goal to bring tables of intensity and time series into use, since every athlete, if we reason with a scientific method, can depart from their own X value and improve up to a value of Y. Only based on this reasoning is it possible to employ HIT with an athlete; otherwise, it is better to stay with other methodologies which, while perhaps less performance-enhancing, definitely allows the trainer to make more extensive assessments.

Authors

Gian Mario Migliaccio, PhD

Sport Science Phd, Head of Sport Science Lab (UK) . Was director for 4yrs on a branch of the Italian Olympic Comitteee for a Scientific Project where conducted more than 100 researches with high level athletes. Has more than 50 researches published

Johnny Padulo, PhD

Sport Science Phd. Lecture in the Italian University eCampus of Novedrate (Como). He is also scientific editor, reviewer and author/co-author of more than 100 researches

References

1. Balsom PD, Seger JY, Sjodin B, et al. Maximal-intensity intermittent exercise: effect of recovery duration. Int J SportsMed. 1992.
2. Billat LV, Interval training for performance: high-intensity or high volume training?, Scand J Med Sci Sport, 2010
3. Buchheit M, Laursen PB, High-Intensity Interval Training, Solutions to the Programming Puzzle Part 1 (Cardiopulmonary emphasis) , Sports Med, 2013
4. Buchheit M, Laursen PB, High-Intensity Interval Training, Solutions to the Programming Puzzle Part 2 (Anaerobic energy and neuromuscular load) , Sports Med, 2013
5. Chamari K, Padulo J, ‘Aerobic’ and ‘Anaerobic’ terms used in exercise physiology: a critical terminology reflection, Sports Medicine Open, 2015
6. Hellard P, The development of a research department in the French Swimming Federation: a paradigm evolution, XIIth International Symposium on Biomechanics and Medicine in Swimming, 2014
7. Laursen PB, Jenkins DG, The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes, Sports Med, 2002
8. Robergs RA, A critical review of the history of low- to moderate-intensity steady-state VO2 kinetics.. Sports Med 2014
9. Rushall. B., Belief-Based Versus Evidence-Based Coaching Development [Online] San Diego University, 2009
10. Stager J et all., Assessing the evolution of swim training via a review of Doc Counsilman’s training logs ,  XIIth International Symposium on Biomechanics and Medicine in Swimming, 2014
11. Tabata I et all., Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and ·VO2max, Medicine & Science in Sports & Exercise, 1996
12. Tabata I et all., Metabolic profile of high intensity intermittent exercises, Medicine & Science in Sports & Exercise, 1997