The “sweet spot” has been previously proposed as one of the most effective way to improve cycling performance. The term “sweet spot” is an intensity defined as being between zone 3 and zone 4 (i.e. 83 to 97% of functional threshold power or anaerobic threshold).
The rationale behind this “sweet spot” was to be able to get more “bang for your buck” and to be more time efficient. Although I believe there is benefit by training in this “sweet spot” I would strongly disagree that it is the most effective way to train all year round.
Anecdotal and scientific research supports that this may be an effective way to build aerobic endurance (i.e. get fit), especially among less well-trained individuals. However scientific research studies have shown that a more polarised training approach results in far greater performance improvements. Polarised training proposes training at intensities, which are either very easy, or very hard.
See here for more on Polarised Training.
In brief, polarised training outperformed “sweet spot” training in all measured outcomes in the specific study. These outcomes included long duration efforts (a 40km time trial), as well as well as shorter duration efforts (a peak power outputtest).
As previously discussed in our Periodisation article, the optimal way to structure your training is to ensure adequate periodisation. Conventional periodisation recommends initially building an aerobic base. Once you have established a good aerobic base, you should increase the training intensity.
In my opinion, “sweet spot” has room and rationale for including during an aerobic base phase, however for optimizing performance you should rather focus on training intensities above your threshold.
I often use the analogy of trying to move a heavy object (your functional threshold). You are not going to be able to move this wall without touching it. You need to think in terms of pushing through an object if you want to move it.
Training to raise your FTP works the same way.
If you want to improve your functional threshold, you can’t be training just below it, you need to push beyond it!
So in summary, “sweet spot” training may get you fit, but if you want to get fast, avoid the “sweet spot” and focus on hard efforts above threshold.
