Shownotes

Åland Ötillö

01:50 -

• The Ötillö race I did last year was one of the most beautiful and demanding I have competed in. It was the first time the event was held in that location, with highly technical terrain, difficult rocks and very cold swims.
• Despite that, or perhaps because of it, I enjoyed it enormously and I am going back this year. The course has actually existed for longer than the Ötillö format, having previously run as an independent all-in swimrun event, and it sounds like the experience was similar.
• One moment that captures the spirit of the race is a jump off a cliff into the sea, which apparently even made it into a drone promo video one year. It is an event anyone interested in swimrun should seriously consider.
• Living in Switzerland, I would also put the race in Engadin forward as another strong option.
• What makes it stand out is the reversal of perspective: instead of swimming between islands, the big climbs take you high enough to look down and see the lakes spread out below between sections.
• It is a different kind of scenery but equally striking, and with the trail running element it suits athletes coming from that background.
• For anyone who has spent time in Switzerland, the country's natural beauty is hard to match, and the race reflects that well.

Torque training under the microscope

00:03:53 -

• A recent study from Spanish researchers, published in the Scandinavian Journal of Medicine and Science in Sports, looked at the role of pedaling intensity during torque training in cyclists over ten weeks.
• There were three groups: a control group continuing normal training of around ten hours per week, a high-torque group, and a low-torque group.
• The two intervention groups both completed two torque sessions per week on top of matched training volumes and intensity distributions.
• The high-torque sessions were five very short sprints, just seven maximal pedal strokes from a stationary start on a 6% climb at 40 RPM, with four-minute rests between efforts, targeting 70% of each athlete's measured maximal torque.
• The low-torque group did five by four-minute intervals at 70% of maximum aerobic power, roughly 90 to 95% of critical power, at 50 RPM, which corresponded to about half the torque of the sprint group.
• Both intervention groups improved their 20-second sprint power more than the control group.
• The high-torque group also improved peak sprinting power and quadriceps cross-sectional area.
• There were no statistically significant differences between the two intervention groups, though the authors acknowledged the study was underpowered to detect them, and there were some indications that the sprinting group may have had greater gains in maximum aerobic power and time to exhaustion.
• It is a good idea in principle to do strength work in the actual discipline, but the lack of clear separation between groups makes it hard to draw firm conclusions.
• What I would take away is that the high-torque sprints are worth including because the opportunity cost is essentially zero.
• Seven maximal pedal strokes five times over the course of a ride, whenever you hit a hill, will not generate meaningful fatigue for most cyclists or triathletes.
• If anything, the more interesting finding is that the five-by-four-minute low-torque intervals showed no significant improvement over the control group, which is the format more commonly used in practice. 
• That raises a real question about opportunity cost. If a low-torque session is replacing something else in the training week, the evidence for doing so is not strong, and that is where I would be more selective.

Ketones and endurance gains

00:11:50 -

• The second study I want to discuss comes from the Journal of Physiology and is titled "Post-Exercise Ketone Supplementation Improves Endurance Performance and Mitochondrial Adaptations During an Eight-Week Endurance Training Intervention."
• What makes this study stand out is its duration. Eight weeks is a meaningful training block, structured as two three-week progressive phases each followed by a lighter recovery week at 40 to 50% of normal volume.
• Cyclists were split into two well-controlled groups, with careful monitoring to ensure the ketone group was actually taking their doses correctly, including verification of pre-sleep intake.
• The dosing protocol was higher than I expected: 25 grams of ketones taken after training and another 25 grams 30 minutes before bed, five days a week for the full eight weeks.
• The results were notable. Compared to the control group, the ketone group improved their 30-minute time trial power output by 4% and their VO2 peak by 6%.
• Those are meaningful differences for a study of this length, and the consistency of the protocol and the size of the adaptation make this one worth paying close attention to.

Ketone cost and practical use

00:14:10 -

• The cost of following this protocol is worth addressing directly. KetoneAid, which was the actual product used in the study, costs around $30 per dose.
• At two doses per day over five training days a week for eight weeks, replicating the study protocol would run to roughly $1,800. Using DeltaG ketones instead would push that closer to $3,000. These are not trivial sums.
• That context shapes how I think about practical application. Taking a small pack of ketones here and there for $100 is unlikely to produce meaningful benefit.
• The study is fairly clear that the gains came in the second four-week block, not the first. After four weeks, the control group and the ketone group had improved at roughly the same rate.
• It was only in the second half of the intervention that the ketone group pulled ahead. So this is a committed, long-term protocol, not something you dip into occasionally.
• Where it could make more practical sense is in a concentrated training block before a major race, or during a training camp where you are pushing well beyond normal loads.
• Earlier work from the same research group found that athletes who were in a state of overreaching and took ketones during a three-week period showed some protection against going into a deeper overreaching phase.
• Applied to a training camp, the idea would be that ketones might prevent you from digging as deep a fatigue hole by the end of the week, which could mean a faster and more complete recovery afterwards.
• One question mark I would flag about the study population is that the athletes had a VO2 max of around 57 to 59, but a baseline 30-minute time trial of 250 watts, and only four hours of weekly bike training going in.
• Those numbers suggest they may not have been trained cyclists at all, possibly team sport or CrossFit athletes.
• That matters because the mechanism behind the performance improvement appeared to be peripheral adaptation, primarily mitochondrial content, which tends to saturate more quickly as athletes become better trained. 
• It is plausible that the effect would be smaller in genuinely well-trained cyclists, though one could also speculate that athletes who have already plateaued in their peripheral adaptations might be candidates for some additional stimulus from ketones.
• That remains an open question for future research.

Carb loading before Kona

00:22:40 -

• A study accepted by the European Journal of Sports Science looked at pre-race nutrition behaviours in female endurance athletes at the 2024 Ironman World Championships in Nice.
• It combined food diaries and food photography submitted by athletes in the 48 hours before the race plus race morning, with qualitative interviews conducted both before and after the event.
• The qualitative side is a legitimate and well-established approach, and it adds a layer of insight into why athletes make the choices they do, not just what they ate.
• The quantitative findings were telling. Average carbohydrate intake on the day before the race was 6.4 grams per kilogram body weight, with the day before that being even lower.
• The standard recommendation for a two-day carb load is 8 to 12 grams per kilogram per day. Only six of the 23 participants reached 8 grams per kilogram the day before the race, and none reached 10.
• Average fibre intake was 21 grams per day, and there was a strong correlation between fibre intake and GI symptom severity, with essentially everyone consuming 30 grams or more of fibre scoring above the threshold for significant GI symptoms.
• One important correlation worth flagging is that higher carbohydrate intake was associated with better race performance.
• The two clearest signals from the data are therefore that higher fibre most likely drove GI problems, and that the athletes who ate more carbohydrate performed better.
• The qualitative findings identified two broad types of athlete: those focused on completing the event and those focused on competing.
• Predictably, the competitive group was more likely to have and follow a structured pre-race nutrition plan. Having access to a kitchen, such as a rental apartment, was a facilitating factor for good execution.
• Travel logistics, heavy social commitments in the days before the race, and pre-race anxiety that suppressed appetite were the main barriers.
• A methodological consideration worth raising is under-reporting. Food diary studies consistently show that athletes report less than they actually consume, and in a race context this could mean athletes were even further under-fuelled than the numbers suggest.
• Separately, it is worth remembering that a large breakfast on race morning will not meaningfully replenish glycogen stores within three hours.
• If the two days of loading have been insufficient, athletes are starting the race in a deficit that breakfast cannot fix, which makes those two preparation days even more critical than they might otherwise seem.

Practical carb loading strategies

00:30:05 -

• One of the clearest takeaways from this study is the importance of front-loading the carb load rather than leaving it to race morning.
• By the time you wake up on race day, your preparation window is effectively closed. A large breakfast is not going to replenish glycogen that was never topped up in the two days prior.
• Race morning should be a normal, comfortable meal that sits well in the stomach, not a last-ditch attempt to compensate for days of under-fuelling.
• When it comes to the structure of the load itself, starting early in the day matters. Getting 60 to 70% of your carbohydrate target in before midday gives your body the best chance of converting it into muscle glycogen, which can take up to 48 hours.
• Eating a large dinner the night before the race, particularly if you are panicking about having eaten too little during the day, risks disrupting sleep and leaving you feeling heavy on race morning.
• Hitting 10 grams per kilogram of body weight through whole food alone is genuinely difficult for most people, and I would not recommend trying it for the first time before your most important race of the season.
• Practise the approach before a key training session first. My own solution is to combine nutrition and hydration: one litre of water with 100 grams of sugar and 1,000 milligrams of sodium, taken twice through the day, delivers around 200 grams of carbohydrate without requiring any additional food volume.
• That covers roughly a third of the target for many athletes and makes the rest of the load far more manageable alongside normal meals kept plain and low in fibre.
• Planning the specifics in advance also matters. At least the first few times you do a proper carb load, you need to work out the actual gram targets for your body weight, identify the foods you will use, and do the arithmetic before the day arrives. It is not something most people can manage intuitively given how high the targets are.
• On the logistical side, booking accommodation with a kitchen removes one of the biggest barriers identified in the study.
• Athletes who could cook for themselves were in a much stronger position to control what they ate and when. Social commitments are harder to avoid entirely, but you can plan around them.
• Bringing snacks to race registration or other pre-race engagements means the carb load does not have to stop just because you are away from your accommodation.
• The behavioural framing matters too.
• Athletes sometimes resist carb loading because it conflicts with how they normally think about eating well, but for two days before a race that has taken months and considerable expense to prepare for, the cost of doing it properly is negligible in comparison. 
• I try to make that explicit with the athletes I work with. I also find that building a consistent race week structure helps significantly.
• If athletes know they will always have a rest day on Thursday before a race, for example, they can plan travel, social arrangements, and other commitments around that in advance, long before race week arrives.
• That kind of predictable structure takes the guesswork out of the preparation and makes good execution much easier to repeat.

Carb loading: athlete examples and coach tactics

00:38:50 -

• Two participant quotes from the study capture the range well.
• The athlete who came closest to the targets, reaching 9.9 grams per kilogram on the day before the race, described having a tight, repeatable plan built around bringing the right foods with her and taking snacks when out and about. 
• No GI symptoms, no issues. The athlete at the other end, who consumed just 2.8 grams per kilogram, said she ate as usual, had no real plan, and avoided anything that might weigh her down on the climbs.
• That last point is worth sitting with, because whether consciously or not, it reflects a kind of pre-race dietary restriction that is probably worse for performance than eating too much fibre.
• What strikes me as a coach is that most of these athletes already knew the guidelines. The gap was not in knowledge but in behaviour.
• Knowing you should eat 10 grams per kilogram and actually doing it on a busy pre-race day with travel, registration, and social engagements are two different things entirely.
• That is a useful reminder that telling athletes what to do is only part of the job.
• One approach I think is worth adopting is putting an example food diary for the day before the race directly into the training platform, showing exactly what to eat, when to eat it, and how much.
• Not just a carbohydrate target in grams per kilogram, but a concrete example with breakfast, snacks, lunch, and dinner mapped out. Unlike a ketone protocol, this costs nothing and is available to every athlete.

Training the negative split

00:43:20 -

• This next paper is what the authors themselves call a mini-review, titled "Developing Negative Split Pacing in Endurance Athletes."
• Most endurance athletes understand that negative split pacing, finishing faster than you started, is the optimal approach for long races.
• In shorter triathlon formats with drafting and tactical considerations it is less relevant, but in Ironman it matters considerably.
• Recent marathon world records from both Sawe and Kipchoge featured surprisingly large negative splits, which reinforces that this is not just a theoretical preference.
• The authors had previously published a paper identifying energy conservation, thermoregulation, perceptual regulation, and fatigue resistance as the key physiological and psychological factors underpinning a successful negative split. This paper attempts to turn those findings into practical training guidelines.
• The sessions they suggest include sustained tempo runs and cruise intervals to build lactate threshold, back-loaded intensity work within sessions to develop fatigue resistance, and RPE calibration exercises where athletes train using only one feedback source at a time, pace or power or perceived effort, rather than all of them simultaneously.
• For race-specific preparation, they recommend progressive runs, fast finish runs, and interval sessions where intensity increases across the set.
• They also suggest this kind of targeted work should be concentrated in a final pre-race training block rather than distributed evenly across the whole plan.
• A couple of sessions I would add for listeners. The first comes from Renato Canova and works well for marathon runners: four kilometres at 98% of race pace, two by three kilometres at 99%, three by two kilometres at 100%, and four by one kilometre at 101%.
• The intervals shorten as the intensity climbs, making it a natural progression. The second is a midweek five kilometres at marathon race pace.
• It sits in a similar space to the high-torque sprint idea discussed earlier, in that it is not a demanding session, but it trains something specific.
• When athletes find that five kilometres at marathon pace feels relatively comfortable in training, it recalibrates their perception of what the early kilometres of a race should feel like.
• That perceptual anchor can be genuinely useful on race day.
• The paper has some limitations worth acknowledging. Some references did not fully support the claims being made, and certain suggested microcycles felt contrived.
• It reads at times more like a book chapter than a research paper.
• That said, the core material on why negative splits matter, what physical and perceptual qualities are needed, and which session types develop them is solid and practically useful.

Negative split pacing in triathlon

51:20 -

• The question of whether negative split pacing translates directly to Ironman is a good one.
• A study looking at the top 30 finishers at the 2022 Hawaiian Ironman found that the fastest athletes showed a negative split on the bike, but on the run the defining characteristic was not a negative split so much as minimal variability in pace. 
• That aligns with the intuition that even splits through the marathon, rather than a strict negative split, is what the best athletes are actually achieving.
• For amateur athletes, replicating that level of durability is genuinely difficult given the training volumes professionals sustain.
• That said, some of the fatigue resistance work discussed in the paper does carry over.
• Simulation sessions that combine a well-paced bike effort with an even-paced run are a practical way to rehearse the conditions of the race, even if a slight slowdown in the final kilometres is inevitable.
• The bigger point for Ironman, though, is that run pacing is downstream of what happens on the bike and swim.
• How well you manage the bike leg, particularly on a rolling course where it is easy to push too hard over short climbs without it feeling difficult in the moment, will determine more about your marathon than any run-specific pacing session. 
• Research in trail running shows something similar: the fastest athletes produce very uneven splits but modulate their effort extremely well, pushing hard on descents they have trained specifically for, while slower athletes fail to regulate effort across the terrain.
• On an Ironman bike course, that means actively holding back on climbs, using power as a guide, and understanding the cumulative cost of small surges before they show up in the run.

LINKS AND RESOURCES

• Daniel’s Substack (Endurance: Ideas + Implementation) and website
• The Role of Pedaling Intensity During Torque Training in Cyclists: A Three‐Arm Randomized Controlled Trial - de Pablos et al. 2026
• Post‐exercise ketone supplementation improves endurance performance and mitochondrial adaptations during an 8‐week endurance training intervention - Robberechts et al. 2026
• From Intention to Execution: Pre-Race Nutrition Behaviours, Influences, and Performance Outcomes in Female Endurance Athletes at the IRONMAN® World Championships - Fortis et al. 2026
• Developing negative split pacing in endurance athletes: practical guidelines and training models - Grivas et al. 2026