Interval Training: A key to successful performance
Recently, every time I see “interval training” used on social media, it seems to be from a “burn fat fast” perspective.
The general, full body, maximum calories/ minimum time approach. Great- interval training can be used as a tool to aid in body composition improvements, as a time efficient way to create/ enhance an energy deficit. If fat loss is your goal, interval training may be a good option. (for more on fat loss, take a look here).
Interval training is way more than “training for fat loss”!
Let’s go back to before the time of “I can have the body of my dreams for 3 minutes a week” (By the way, you can’t, and won’t). Interval sessions have been popular by elite athletes for decades, and we now understand more than ever about how to apply it. Step away from the “burn fat fast” mindset, and let’s look at how interval training can help you to perform at your best.
If performance improvement is your goal, a considered and intelligent use of interval training is a must! Understanding the real benefits and applications of interval training is tricky. Lucky for you, this article will discuss interval training for sports performance, and give some take home recommendations for both endurance sport athletes (marathon running/ cycling/ triathlon, etc) in addition to intermittent team sports (football, hockey, netball, rugby, etc).
Whether you’re a coach or an athlete, these methods will help you to take a considered approach to interval training to get the most benefit for you!
What types of sports performance will benefit from interval training?
In addition to the obvious appeal of time efficient training, specific interval training has shown benefits above other types of training (continuous endurance or competition type sessions only) for field sport athletes (Hoffman, 2014), endurance athletes (Seiler, 2010) and “intense sports” (sports between 1-8 minutes of high intensity work in duration, such as rowing or track cycling) (Laursen, 2010).
Although the volume of interval training may be relatively low as a percentage of total training volume, this may be the critical element that moves performance forward.
Different types of interval training commonly used include percentage of Threshold interval training (%T), High Intensity Interval Training (HIIT), Sprint Interval Training (SIT), and Repeat Sprint Training (RST). All have their own uses in performance and should be selected based on the adaptations required, in addition to other considerations. This will vary both between different sports, and between different training phases within the same sport.
Selecting interval training types
When selecting which type of interval training to use, how to use it and how often, is generally a job for the coach with an in depth understanding of performance physiology. However, some key points to consider include factors we can plan for well in advance, for example:
• What is the physiological adaptation desired for the session?
• What time is available for the session?
• What other adaptations are required during the training phase?
• How will I monitor intensity of the training session?
In addition to some factors that we may need to make a decision on closer to the session, for example:
• How is the athletes readiness to train?
• What impact will the session have on the rest of the training week?
• What is the priority for the session/ training week (eg competition schedule)?
• How will this impact the mental state of the athlete?
Without considering all of these factors (and more), you will not maximise the benefits of interval training. We suggest you work alongside your coach to determine the detail of appropriate sessions.
Interval training for endurance performance
If you are an intermittent sports athlete, feel free to skip ahead to the next section.
For Endurance Performance, the majority of training (around 80%) is often made up of low intensity, high volume work (Seiler, 2009). However, the key to improving performance is likely to lie within the remaining 20%- the higher intensity work (Laursen, 2002).
For endurance athletes (runners are used for the example, but the systems apply throughout endurance performance), testing to establish pace or HR targets is often seen as best practice to determine interval length. This can look to determine the maximum heart rate, the lactate threshold, the maximum aerobic speed, and useful training zones for both speed and heart rate. The use of individualised HR zones, based on either HR or HR reserve (such as the Karvonen system), appears to be a useful way to establish training zones for maximum aerobic training (see figure 1). However, where appropriate, establishing zones based on pace (such as the VDOT system in figure 2) may be used.
A useful general strategy includes a general training phase, with around 80% of specific training volume completed at low to moderate intensities (under the lactate threshold, or zone 1-3 in figure 1), and around 20% completed as high intensities, with HIIT (long- around 8 minutes per interval in zone high 4 to low 5) focusing on developing the cardiopulmonary adaptions required.
Following this general phase, more specific training may include a combination of increased recovery work (20-30%), threshold runs (competition runs) or threshold focused intervals (50%) (zone 4), and intervals with a greater focus on running economy (eg. HIIT short- 3x 4 minutes work or 4x 3 minutes work) (Zone mid to high 5).
Again, these examples are just that. Examples. Any decision on interval type/ duration should be considered in full, based on your individual situation. Other strategies, including working from the anaerobic threshold, may be used for longer intervals.
But one thing is clear, the “go as hard and fast as possible all the time regardless of distance” approach is likely to end in disaster.
One thing to remember, may be that your recovery days should feel very easy, aerobic endurance should feel easy, threshold intervals should feel moderate- very hard depending on interval used, and races and HIIT sessions should be hard/ maximal. If you race regularly, treat some races as lower priority training runs where possible to allow adequate recovery and adaptation.
Even if not using HR to determine speed, it can be a valuable tool to assess the loading on your body (sometimes, a slow run is still a very hard run!). However, it is important to remember that different routes, elevations, surfaces, and other environmental factors will impact your pace and HR, in addition to physiological factors such as dehydration, so learning to honestly and accurately “feel” where you are at physically is a skill that should be developed through training.
Interval training for intermittent sports (and “intense, short duration” sports)
For Endurance athletes, feel free to skip to the summary.
Firstly, here it may be important to put into ccontext that although some athl;etes may see “speed development” through interval training, we feel that a solid foundation of speed should be developed separately with maximum speed and acceleration sessions and training blocks where possible. The focus of interval training is the maintenance of this speed, through either repeated effort with limited recovery.
The type of interval training selected should be put into context with the time in the season, as well as the desired adaptations for that training period. Again, this should be monitored accurately- and again may be done on a HR or speed basis.
It should be noted that this will only give part of the information on loading, as some of the very high intensity movements during specific training sessions (eg cuts, decelerations, accelerations, and other key movements, may have a fatiguing effect that is not measured by total distance covered or HR fluctuations. GPS goes towards monitoring this, but for most clubs/ athletes, this may be impractical. Either way, although pace and HR can be used for some session prescription, other factors must be considered in the context of the plan as a whole.
For team sports, the interval type used should be depending on the phase of training, moving from the more general to the more specific (Hoffman, 2014). In addition to this, individual fitness and response (Faude, 2013) and injury risk and fatigue considerations must be considered (Bucheit, 2013).
For general fitness adaptations (cardiopulmonary fitness), HR focused intervals (using the mode of training in the sport- for example footballers run!), short HIIT sessions 3-5x 3-4 minutes work with equal recovery may be appropriate. HR values should reach around 95%-100% maximum for a total of 7-10 minutes during these sessions for most individuals. However, this must be assessed on an individual basis, as this may be too much (or too little) to maximise adaptation. This type of session is most likely to be appropriate early on in the early pre-season phase.
Building towards the start of the season, SIT intervals of shorter, more intense work blocks (eg 30s of shuttles) may be introduced, with a focus on longer rest durations, with low intensity active recovery considered.
During the season, specific adaptations may be best gauged from repeated sprints and small sided games, to work specific speed qualities, skill and cardiopulmonary qualities and manage the fatiguing effects of the competitive season.
Interval training is a great way to push your performance to the next level. However, selecting appropriate interval length and type is complex. To get the most out of interval training requires honest communication between the coach and athlete. For the athlete, understanding the physiological complexities is difficult, and will often lead to crucial mistakes and injuries, plateaus or performance decrements. Therefore, having a coach who understands this is essential.
The coach (or coaching staff) must be effectively communicating with the athlete, and understand the physical, emotional and psychological stress, and guide/ adapt the programme accordingly. Interval training should feature in most plans, even if only for a short phase, but it should fit around the entire picture of the outcome we are looking to develop.
Used well, interval training can take you well beyond average performance.
But Guessing what intervals to use, when and how, will not.
Josh Kennedy, MSC, ASCC, CSCS
Bucheit, M, Laursen, P, 2013- High Intensity Interval training, solutions to the programming puzzle, part 1- cardiopulmonary emphasis, sports medicine, 43, 313-338
Bucheit, M, Laursen, P, 2013- High Intensity Interval training, solutions to the programming puzzle, part 2- anaerobic energy, neuromuscular load and practical applications., sports medicine, 43, 927-954
Faude et al, 2013- high intensity interval training vs high volume running training during pre season conditioning in high level youth football. A crossover trial, journal of sports sciences, 31(13), 1441-1450
Hoffman, J et al, 2014, repeated sprints, high intensity interval training, small sided games: theory and application to field sports. International journal of sports physiology and performance (9), 352-357
Laursen, P., 2010, training for intense exercise performance, high intensity or high volume training. Scandinavian journal of medicine and science in sports, 20, 1-10
Seiler, S, Tonnesson, E., 2009. Intervals, thresholds, and long slow distance. The role of intensity and duration in endurance training. Sports science (13), 32-53