It’s not the coffee, it’s the break:
So that’s why weekend warriors spending an hour at the cafe mid ride are all so lean
It is very interesting though, generally speak twice daily workouts seem to be frowned upon or seen as a novelty with perhaps some benefits but should only be toyed with periodically.
From an intensity POV I get that, but if you’re doing polarised then this could be great news. No time to download and read the whole PDF but I’m assuming both workouts were endurance? Or high intensity followed by lower intensity?
Not read the article but 2 workout sessions in a day is almost universal in other endurance sports. It’s also becoming slightly more prevelant in cycling.
Yep, Us triathletes tend to do two per day (if not every day) fairly regular
I was curious what the riders were doing. Here’s what I pulled from the study:
participants cycled for 100 min at a power output corresponding to 50% of the difference between LT1 and LT2 (124 ± 27 W, 54 ±5% of MAP). Then, after an 8-min rest, participants performed six 1-min exercise bouts at 125% MAP (287 ± 46 W) interspersed with 1-min rest period
High intensity ride:
5-min warm-up at 90% LT1. Participants completed ten 2-min intervals at an intensity of 20% of the difference between the LT2 and MAP (182 ± 38 W, 79 ± 5% of MAP). Each 2-min bout was interspersed with a 1-min passive recovery period
I haven’t gone through and read the whole thing in detail, just picked out the parts I was most curious about so far.
TLDR: 2 hour glycogen depleting ride first, using a protocol that has been found to deplete glycogen. Then a short/long break(depending on group), followed by the high intensity ride.
But you have to hit the same muscles to see this effect:
I wonder if there is a limit to the length of the break? Could you do one workout in the morning and one in the evening, or would you lose this benefit? @roflsocks Pulled the workouts, I wonder if you could do the long ride in the morning and the High intensity ride in the evening and get the same effect?
From the introduction of the study report:
> It is well known that the transcriptional response of many genes peak 3 to 6 hours post exercise and return to basal levels within 8 to 12 h [5, 13, 26-29 81]
Based on that one can assume that 6 hours could be considered as an upper limit. But this is probably something that needs more studies. For example, look at the studies on rats above. 3 hours of easy aerobic exercise. Really easy:
Max at 6h but still some elevation after 18h. However, all human studies so far (as far as I can tell) show basal levels at 8-12h. And those haven’t even touched the variability introduced by training status and/or training modality (e.g. HIIT vs MIT vs LIT)
Read a bit more of the study. One thing that caught my attention was the control group did far less volume than the two experimental groups. The control group did not do the 2 hour depleting ride at all, and simply only did the high intensity exercise.
I found the contrast between the two experimental groups interesting, and useful. The study’s design falls a bit short on the control group, because it’s unclear if the differences in that group are simply due to lower total training volume, or to the higher starting glycogen levels in that group.
Fundamentally, if you’re trying to answer the question of whether I should do one a day, or two a day, the choice is typically one long ride, vs two shorter rides, of roughly equal total volume. At least, that’s the question that I want answered. I don’t think this study really addresses that at all.
I’d have liked to see a group who did a 3ish hour block and who completed all of the volume prescribed to the other experimental groups, but without a break. That would keep volume consistent, but really confirm the difference you get by taking breaks of various durations. I’m also curious if the order of the workouts matters. My first thought on seeing the study was that you’d do the high intensity work first, followed by lower intensity stuff. But the opposite was used in this case.
I have a lot of follow up questions that aren’t addressed by this study. I want to know more about how this fits into a larger training plan. Given equal volume of two plans, if I’m doing two-a-day workouts, do I have more time off the bike? Is recovery better or worse with this strategy? Is it still best to ride depleted on the 2nd ride, or would it be better to re-fuel as much as possible before that second ride?
I’ve asked myself similar questions when reading the paper. I do not fully get their conclusion that lower glycogen does not play a major role. I don’t see that. Or I just don’t understand everything.
I also would like to understand the difference to a long ride and/or carb fed or not. But what can be said is that two shorter rides within a couple of hours seem to be more than purley the sum of hours of the two rides. For me this is quite relevant because this reflects my use case: I work home-based. I can easily do two 2 hours within that mentioned period whereas 4 hours for a single workout is not often possible. Add that 4 hours on the trainer is quite a stretch. Therefore, it is a comfort for me to know that there are some initial indications that two times 2h (or whatever) seems to be better than previously thought.
And it is important to note their final statement:
Altough we have identified novel molecular mechanism by which the twice-a-day approach might be a more effective strategy to induce adaptations related to mitochondrial biogenesis and fat oxidation, further research is required to determine if training using the twice-a day approach results in greater changes in mitochondrial content and function and fat oxidation.
We know more about the potential mechanism, the next step is to see how we can implement it in training regimes.
Yesterday went pretty well. 2:20h (indoors) + 4h outdoors. Endurance day with some low cadence work and lowish tempo work. And hopefully the effect was greater than the sum of its parts.
What still puzzles me is the question on withholding carbs between the two sessions. Necessary?
However, I will continue with carb restriction for reasons of specificity. My races are longer, 4 to 11 hours, and always include intensity in the first part. You burn through your glycogen stores right in the beginning. To be competitive fatigue resistance is key and this means being fast while being low on glycogen. That’s why I intend to keep doing it “low style”. And hope to get some additional benefits by extending the period of elevated PCG-1a expression.
Just for context setting, this is quite interesting, as well. One of the original studies on this topic.