Frank Overton can be blamed for the “sweet spot” trend, for better or worse. I’ve been hearing about it for almost a year now and always questioned the science on it, because there isn’t any, at all. Frank’s claim is that people should trust coaches who work with endurance athletes every day and not “scientists” with the disclaimer that he was/is a scientist himself. I was very cynical, still am. But the basic premise is worth considering and testing out for myself.
The “sweet spot” is 84-97% of FTP. For me (FTP currently only 220) that’s 183-213 watts which, ironically, felt “sweet” over the last few days. This is the upper “tempo” (zone 3) and lower “threshold” (zone 4). It’s also the exact place that others practicing periodization have called “junk training” for years, the type that wears you out without producing results. There are absolutely no scientific results to back Frank’s claims, but Frank doesn’t care. He says scientists just haven’t “discovered” it yet. And he might be right.
A lot of science is slow to acknowledge what people with experience feel and observe in their own lives. For example, a study recently confirmed what I have been saying for years: that artificial sweeteners make people fatter than sugar because the sweetness tricks the brain into thinking sugar is entering the blood stream forcing to pancreas to pump insulin (shutting down fat conversion) for sugar that never comes. I have been complaining about this forever. Artificial sweeteners spike hunger pains way worse than cane sugar alternatives. Sugar is not bad, excessive sugar is. In fact, I’m taking a refillable “bonk protector” bottle of my own light corn syrup concoction (some prefer maple syrup) with me on ever ride these days, way cheaper than “Gu” and just as effective if already supplementing water with electrolytes and vitamins.
TSS stands for “training stress score” not “toxic shock syndrome” (which just shows that Training Peaks, who invented it, doesn’t know how to Google search, because fitness people aren’t all that bright sometimes). It’s an attempt to show how much recovery you will need based on how much intensity over how much time. It has a number of very significant flaws but is the main way all the apps out there show the stress of that last workout. Just remember that this takes no consideration for how stress exponentially increases from hour to hour (versus linearly). It seems to work if (and only if) you use it for workouts three hours or less.
TSS is also the basis of “fatigue dependent training plan design model (FDTPDM)” which is another Frank-ism. It’s just a fancy way of saying “you should rest between hard workouts” but Frank, the inventor of buzz-words and bullshit acronyms cannot simply say that. He has to make up some impossible to remember acronym so he can make a stupid podcast that people will click on and suffer through because it looks more official. None of that matter, however, it still works, because sports medicine professionals have been saying this for over 50 years.
As much as I hate to admit it, I think I have been doing the “sweet spot” stuff most of my endurance sports career and just never called it that. The only difference is that now I can do that without shame. I always end up going harder than I should and landing in tempo/threshold and force myself to take a rest day when I wasn’t planning on it.
And honestly, I despise threshold and power intervals. They are painful, injury prone, and take forever to recover from. Instead of threshold intervals for building power, weights and race-pace intervals are better. Turns out “sweet spot” is just another name for “race pace.”
One year as a triathlete I wanted to focus on power so I upped the time in the gym on the off season building leg muscle power and kicked ass that year. I didn’t do a single threshold interval. Instead, when I would go out for rides, I would simulate a race and turn down the length so I could recover. My “high intensity” training modeled my racing exactly to my technique and feel during a race matched it exactly. Then, I would do long, slow recovery rides on the off days with 1-2 completely off days for full recovery. Guess what, I was doing “sweet spot” training that whole time. The only difference is, sometimes I felt guilty for doing it that way, oh yeah, and it didn’t have a name.
So I’m going to just keep doing “sweet spot” training with adequate rest in between. Here’s what a week looks like (based on my 220 FTP currently):
| Day | Hours | Total TSS | Intensity | Low | High | Workout |
|---|---|---|---|---|---|---|
| Mon | 0 | - | OFF | - | - | rest, yoga, recovery ride |
| Tue | 1-2 | 120-300 | Hard | 183 | 213 | short SST, race, sprints |
| Wed | 1-2 | 100-140 | Medium | 167 | 198 | short tempo intervals |
| Thu | 1-2 | 40-100 | Easy | 123 | 165 | short zone 2 |
| Fri | 0 | - | OFF | - | - | rest, yoga, recovery ride |
| Sat | 3-5 | 400-500 | Hard | 183 | 213 | long SST, race, sprints |
| Sun | 2-5 | 100-200 | Easy | 123 | 165 | long zone 2 |
During consecutive training days (TWT, SS) the total TSS should not exceed 600 to allow full recovery before the next one. This can be split in different ways across those days with the first day in each being the hardest with the most TSS since body is the most fresh on that day. It is better to do something on each consecutive training day than everything on one of them and nothing on the others.
Total hours: 8-16
Sometimes I’ll replace Saturday hard ride with a race or group ride event. Then Sunday can be dialed back as needed based on intensity of Saturday. Thursday is similar. It can be dialed way back if went too hard on Tuesday and Wednesday. Best indicator that I need to back off is soreness and elevated morning heart rate. I’ll always know I’m going too hard or my recovery is bad if on the morning of a hard day I don’t feel really anxious to put in some watts.
It doesn’t matter if the training sessions are all in one or broken up into one hour minimum sessions. The results are the same. This means that on Tuesday I could do one painful workout with five sweet spot intervals or two with three in the first and two in the second. In fact, at my age, breaking up the hard stuff into small bits is preferred for better recovery pretty much every week until (and if) I am targeting a specific event of two hours or more in which case Saturday will always match that event length at or slightly below the pace and intensity of that specific event. The build up of fatigue of two workouts in a day is actually less than one long workout in that same day. Since most every event/race that I care about will be in Zwift I can easily reproduce that target event as much as I want—with a group—every week.
One thing to remember when doing sweet spot training is to seriously up the carb intake—especially during the hard efforts, even the short ones. The hardest part of recovery when upping the intensity like this is re-stocking glycogen in the muscles and liver. The danger here is not getting fat during training, but getting fat after training. All those eating habits continue even after you stop training, but now the thing burning up all that fuel isn’t happening. This is why so many world-class athletes become big fat blobs in their older years. They never adapted their eating habits and cut all their training. I know because I have been that guy before. It is particularly dangerous for athletes because we think we can get our fitness back any time we want, because we’ve done it so many times before. But as we age this stops being true and maintaining because so much more important.
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