High-intensity training: one size doesn’t fit all

In recent years, there’s been a torrent of research showing that adding some high-intensity training (for example high-intensity intervals) to an endurance-based training programme produces big gains in performance. What’s less clear, however, is the best way to structure this high-intensity training. For example, how hard should each interval be, how long, how many repetitions and how many sessions per week should be performed? Do too little or do it too gently and you’ll not get the maximum benefit.
Do too much/too hard/too often and you risk a drop in performance, overtraining and burnout. The answer, of course, is that it will depend on your current fitness, training workload and experience and your recovery ability, but that still leaves a lot of unanswered questions. However, a new study by South African scientists seems to provide a better approach to this conundrum, which could be particularly useful for cycling coaches as well as cyclists with a good understanding of basic exercise physiology.

In the study, the researchers wanted to find out whether a sub-maximal cycling test could be used to monitor and prescribe better, more individualised high-intensity interval training in cyclists with a good baseline level of fitness. To do this, two groups of male cyclists (15 in all) completed four high-intensity interval sessions over a 2-week period. The ‘conventional’ training group followed a predetermined and standardised training programme while in the ‘flexible’ training group, each cyclist had the timing and structure of their interval sessions
prescribed based on the results they obtained in the submaximal cycling test (known as the ‘Lamberts and Lambert Submaximal Cycle Test’ or LSCT for short). The scientists then looked to see if the interval sessions based on the results from the LSCT were more effective at improving 40km time trial times than the ‘pre-prescribed intervals’.
The LSCT is a three-stage test, which involves riding at three different power outputs – at 60%, 80% and 90% of maximum heart rate – during which perceived exertion, power output and speed/pedalling cadence are measured. The rate at which the heart rate recovers after each of these three stages is also measured. The important points to note are that a) even though it’s a sub-maximal test, the LSCT is very effective at predicting peak power and sustained endurance performance in cyclists and this means that the results from the test should be useful to help structure high-intensity training sessions for maximum training effect. When all the data was analysed, it was clear that the intervals prescribed on the basis of the LSCT results were much more effective in improving 40km time-trial times.

Although both groups improved their times, the cyclists in the pre-prescribed interval group improved by only 8 seconds whereas those in the flexible group improved by 48 seconds. The researchers also found that heart-rate recovery (a useful indicator of fitness) after hard efforts was quicker in the flexible group but remained unchanged in the pre-prescribed group. What this study shows is that while there are a wide variety of high-intensity interval workouts that cyclists can perform to improve their cycling performance, choosing a session at
random is likely to be far less effective than creating one based on the results from the LSCT. And maybe that’s not surprising because using the results from the LSCT allows an individual to tailor any high-intensity work precisely to his or her current fitness level. If you want to try this approach, a full description of the LSCT and how to apply it can be found in the British Journal of Sports Medicine (Br J Sports Med 2010;44:i21-i22) and details are also available widely online.

Moreover, although the LSCT is designed using cycling as a model, it’s likely that the same principles are applicable in other endurance sports where better tailored high-intensity sessions are the goal.

Int J Sports Physiol Perform.