Shownotes

Season opener and recent races

00:46 -

• We open the episode in the lead-up to Jack's first race of the season, where the approach in those final ten days shifts meaningfully.
• Rather than grinding through sessions at full capacity, the priority becomes recovery, with more willingness to reduce or reorganise training when the body calls for it. My own preparation has been going well following a 40-kilometre mountain race with 2,200 metres of elevation gain.
• Although I came into it feeling slightly less fit than when I ran the same course the previous year, I had a far clearer execution plan and followed it closely, taking ten minutes off my time and finishing in a notably stronger position.
• What I was most pleased about was moving continuously through the field at every checkpoint, something I had not managed the year before.
• A sharper focus on muscular endurance through strength training, more targeted race-specific preparation, and better attention to nutrition and hydration all played a role.
• With that behind me, the next race on the 1st of May is a UTMB World Series event here in Portugal, in the central mountains, with more elevation and bigger climbs. The same approach, but scaled up to a harder test.
• Jack, for his part, raced a 15-kilometre hilly local road race and won it for the second consecutive year, running about 40 seconds faster than the previous year despite a slightly weaker field overall.
• The notable observation there is how significant the recovery demand is even from a race of that length. Going that fraction deeper in intensity than any standalone training session seems to leave the body and legs compromised for the following week in a way that a hard workout simply does not.
• That is worth keeping in mind when planning the work around races.
• My own recovery from the 40k took around seven days before I introduced any intensity, but I was pleased to get in solid aerobic volume throughout that period, which was better than how things went the year before.

Shoe testing and the Decathlon Kiprun

06:28 –

• I ran in the Puma R3s during my race and was interested in how they compared to other options.
• Jack has been keen to get his hands on the same shoe after seeing strong testing data, and having now raced in them, he plans to run a more structured comparison on the track between the R3s, the Nike AlphaFly 3s he raced in previously, and the Decathlon Kiprun he uses in training.
• Power output and heart rate will be the primary metrics, with the possibility of adding lactate testing as well.
• The Metaspeed is a candidate, though the initial plan already includes the Kiprun as a deliberate choice, given that it sits at a very different price point.
• The durability of the Kiprun has been a genuine surprise. Where the foam on the Nike super shoes tends to break down relatively quickly, the Decathlon option has held up far better over time.
• In terms of raw performance, the gap may be modest. Decathlon's top-end super shoe reaches around 250 euros, which is no longer dramatically cheaper than competitors, but the training model is considerably more accessible and appears to deliver real value.
• The SlowTwitch article noting the shoes reflects that they are gaining wider recognition in the triathlon and endurance space.

Listener questions: maximising commute training

14:01 -

• The first thing worth looking at is whether those rides can be extended. At 40 to 45 minutes each way, they are a solid daily stimulus but still short enough that a modest increase in duration on a couple of days per week could meaningfully lift overall training load.
• Beyond volume, the plan is relatively bike-heavy, so adding short brick runs off some of the commutes, even 20 to 30 minutes of easy running, would help address that imbalance without requiring major schedule changes.
• He acknowledges he is not interested in swimming more, and that is fine, so the focus is on getting better return from what he is already doing.
• Once the structure is more balanced and volume is closer to its practical ceiling within his schedule, the next lever is periodising the intensity based on his event goals and individual profile.
• On that note, he currently runs one intense commute home per week. Moving to two would be a reasonable step forward, and ideally those sessions should sit within extended commute rides.
• A 90-minute ride home gives enough time to properly execute a sweet spot or threshold block, whereas fitting quality work into 45 minutes is tight and limits what can actually be achieved.
• VO2 max work is short enough to potentially fit the standard commute window, but the longer format gives more flexibility across all session types.

Listener questions: finding true threshold with an abnormally high heart rate 

19:18 –

• The intermediate half distance plan uses a 20-minute run test to set thresholds, along the lines of the classic Joe Friel protocol. For an athlete who sits toward the fast-twitch end of the spectrum, a 20-minute test can produce a slightly inflated threshold pace estimate, which would explain why prescribed sessions feel harder than they should.
• The broader point here is that pace zones and heart rate zones rarely align perfectly without a proper lab assessment using ventilatory or lactate thresholds, and in some cases the gap between them is considerable.
• For pace, the approach is straightforward: take the average speed from the 10 kilometre race as threshold pace. At 6:53 per mile, that is a legitimate threshold effort and should be used to reset the training zones accordingly.
• A 20-minute test would typically have produced a slightly faster figure, which would explain the difficulty. Once pace zones are corrected, intense sessions should be executed on pace and RPE.
• Heart rate is worth monitoring throughout for context, to identify whether it is unusually suppressed or elevated, but it should not be the primary driver of pacing decisions in quality sessions.
• For easier endurance runs, RPE remains the primary guide, with pace used as a ceiling for athletes who tend to drift too hard, and heart rate occasionally serving a similar capping function.
• The heart rate zone question is more complex. The standard default of setting threshold heart rate at 90% of maximum is a reasonable starting point for most people, but for athletes with particularly high maximum heart rates it may be closer to 80%, which at a maximum of 210 beats per minute represents a very large difference in practical terms.
• Given that Isaac averaged around 195 beats per minute for more than 40 minutes in his 10 kilometre, a reasonable estimate would place his threshold heart rate somewhere in the mid to high 180s.
• That said, if precision matters, a lab test is the only reliable way to establish it. For day-to-day training, getting the pace zones right and executing sessions on pace is what matters most.
• On the RPE point, this is worth extending slightly. Within a threshold session, the first couple of repetitions should genuinely feel closer to a five out of ten.
• As fatigue accumulates across the session, that perceived effort will naturally rise, and if it reaches six to seven by the final efforts, the execution has been about right.
• Being honest with oneself on that scale across the session then generates useful data, because pace and heart rate collected under those conditions become meaningful reference points to carry into the following weeks.
• Threshold predictions and prescribed zones are useful anchors, but day-to-day conditions vary, and listening to the body first remains the most reliable calibration tool.

Listener questions: strength training for Ironman

25:00 -

• On exercise selection, the priority is compound, multi-joint movements. A front or back squat forms the foundation, with the front squat adding slightly more core demand.
• A Bulgarian split squat provides single-leg stimulus and helps address imbalances and stability deficits. The third movement should target proprioception and the smaller stabilising muscles, making a single-leg Romanian deadlift a strong choice.
• A fourth option worth adding is seated calf raises, specifically to load the soleus, which is particularly relevant for running performance and injury resilience.
• For execution, given that the goal is not hypertrophy, sets of four to six repetitions with two to three reps in reserve and full recovery between sets keeps the stimulus neuromuscular rather than metabolic. Three sets per exercise is a sensible starting point.
• On scheduling, the preference is to pair strength sessions with intensity days rather than easy or long days, placing the gym work after the swim, bike, or run session.
• This concentrates the neuromuscular stress on fewer days and maximises recovery time before the next hard effort.
• One clear boundary is avoiding strength training on the same day as long sessions, where fatigue from the endurance work would prevent any quality from being achieved in the gym.
• For athletes without a strong strength training background, which describes most triathletes, the neuromuscular fatigue generated is moderate enough that placement on an easy day is also workable, even when a hard session follows the next morning.
• On the question of whether strength becomes harmful as volume builds, the answer is that it can compete with key sessions if not managed carefully.
• The solution is periodisation: a more concentrated strength block earlier in the build, when the cost to endurance quality is more acceptable, transitioning to a maintenance approach as long sessions lengthen and race-specific work becomes the priority.
• We covered this in considerably more detail in the base training series, episode five, which is worth revisiting for anyone wanting a fuller picture of how to structure that progression.

Listener questions: maximising cycling fitness when time is limited

30:03 -

• Long rides do help regardless of race distance. Even for sprint distance racing, putting in substantial long ride volume translates into real performance gains.
• That said, for an athlete in Fred's position, the structure of how available time is distributed across the week matters as much as any single session.
• Doing several two-hour rides during the week, or even 90-minute rides, is likely more beneficial for 70.3 performance than a single four to five hour ride on the weekend surrounded by one-hour sessions, even when total volume is held constant.
• Multiple medium-length efforts build aerobic and muscular endurance more evenly throughout the week, and quality work embedded within those rides, threshold or sweet spot intervals in a two-hour window, compounds that effect further.
• A double bike day is another option worth considering, for example 90 minutes in the morning and 90 minutes in the evening. That structure can even accommodate intensity in both sessions if the training load elsewhere allows it.
• The other variable to consider is the quality of time actually spent riding. A two and a half hour outdoor ride that loses 30 minutes at each end to city traffic leaves only 90 minutes of productive work.
• When ride duration is limited, uninterrupted pedalling becomes proportionally more important, which shifts the case toward the indoor trainer, where constant power application is possible for the full duration.
• Tools like Rouvy allow riding the actual race course, which adds specificity. The longer the ride you have available, the more you can afford to coast and recover. The shorter it is, the less tolerance there is for dead time.
• If a longer ride can be negotiated even once a month, three to four hours on occasion, that remains very valuable and is worth pursuing even if it sits outside the normal weekly routine.
• Even if the normal schedule doesn't allow for it, if you can negotiate some way to get a three to four hour ride in once a month, there's a lot of value in that.
• For an athlete at Fred's level, carbohydrate periodisation is also worth exploring on some of those rides.
• Starting a session in a low-carbohydrate state and maintaining that through the first hour to 90 minutes can drive aerobic adaptations more effectively, provided recovery in the days following is managed well and the rest of the week is not compromised.
• The caveat is that this approach only makes sense if the time constraint is the primary limiting factor. If the time limitation comes bundled with significant life stress from work or family, adding a nutritional stressor on top may not be the right call.
• Other options such as a heat stimulus during indoor sessions follow the same logic: they are legitimate tools, but their value depends entirely on the context of everything else the athlete is managing.
• The underlying principle across all of these options is consistency. Additional stressors and periodisation strategies only make sense once sustained, uninterrupted months of solid training volume are already in place.
• If consistency itself is still fragile, the priority is simply to protect and build that first before introducing anything more complex.

Listener questions: monitoring training adaptation

37:36 -

• Formal testing, whether critical power efforts, 20-minute threshold tests, or time trials, has real limitations in this context.
• The results are too sensitive to day-to-day conditions to be reliable on their own, which means the picture needs to be assembled from several sources rather than any single data point.
• Race results year on year remain the most honest signal. It is common to move through an entire winter without any obvious indication of progress, only for that accumulated work to show up clearly on race day.
• That time horizon is uncomfortable, but it reflects how adaptation actually works, particularly as training age increases and gains become harder to isolate in any short window.
• Consistency is the second indicator worth watching closely. If an athlete is repeatedly unable to complete planned training, missing volume and load for reasons beyond the occasional illness, that is a signal that the training load itself may be miscalibrated.
• The ability to sustain good work over a long period without accumulating debt is itself evidence that the structure is right.
• Between formal tests, benchmark sessions, recurring session types repeated every four to six weeks, provide a more practical and less disruptive window into adaptation.
• The goal is not to see progression week on week, since fatigue accumulation during a block will often cause a slight dip in those sessions.
• The useful comparison is across four to six week intervals, where the trend becomes clearer. Formal testing then follows when session data suggests numbers have moved on and zones need updating to ensure the right stimulus is being applied.
• Two more specific methods are worth applying to recurring sessions. The first is RPE logging, done consistently across every session in whatever platform you use.
• If a threshold session that previously felt like a seven out of ten now feels like a six, with the targets held constant, that is a meaningful sign of adaptation.
• The reverse also applies: the same RPE held against higher power or pace targets tells the same story. It is surprising how many athletes using structured training platforms still do not rate sessions consistently, because this is one of the most accessible and reliable ways to compare like with like over time.
• The second method is heart rate drift within longer intervals, particularly at intensities up to threshold. In a session of, say, four by 15 minutes at sweet spot on the bike, the first interval should be disregarded given that heart rate will still be settling regardless of warm-up quality.
• Looking at intervals two, three, and four and tracking the power-to-heart rate or pace-to-heart rate metric in those efforts reveals how stable cardiac response is under sustained load.
• If interval four shows a sharp increase in drift relative to intervals two and three, and then a month later that drift is consistent and flat across all three, that is a clear signal of improved durability and endurance that would be very hard to detect through any other means short of racing.
• Races are ultimately how you really know if you've adapted, but it's also tricky, especially if you only race once or twice per year.
• Factors outside fitness, a nutrition error, an equipment problem in the pre-race bike check, can distort race results enough to obscure the underlying trend. The goal is to execute races cleanly enough that fitness is the determining variable.
• To sustain belief in the process during long periods with little direct evidence of progress, the training structure itself needs to be credible.
• That means either working with a good coach, following a well-designed plan, or having genuinely invested the time to understand how training should be structured.
• Training that has a sound rationale behind it is something you can trust over time. Chasing session-by-session improvements is the opposite of that, and it tends to compromise the consistency that produces results in the first place.
• For a more advanced athlete, seeing a session become slightly easier at the same intensity is the preferred signal, not faster times, because the progression then continues to be built elsewhere in the plan without eroding the reliability of the training process overall.

Listener questions: super shoe effectiveness on uphill terrain

48:23 -

• There is research on this. A paper by Weding and colleagues, which I will link in the show notes, examined the metabolic cost of level, uphill, and downhill running in highly cushioned carbon-plated shoes versus control shoes.
• Using the Nike 4% shoe, the study found a 3.8% improvement in metabolic cost on flat ground, 2.8% on a 5% uphill, and 2.7% on a 5% downhill.
• Metabolic cost here incorporates both oxygen consumption and CO2 production, and at the intensities tested it functions as a close proxy for running economy.
• It is worth noting that a running economy improvement does not translate directly into an equivalent performance gain. 
• A 3% improvement in economy typically produces something closer to a 2% improvement in speed, so the real-world effect is somewhat smaller than the raw figures suggest.
• The conclusion is that super shoes do not lose their advantage on hills, though the benefit is modestly reduced compared to flat running.
• For a race with significant elevation, shoe weight becomes a more prominent factor, and that is worth weighing alongside the energy return properties when making a selection.
• On balance, a super shoe remains the right call for a hilly road race, but the hillier the course, the more attention should go to finding the lightest viable option within that category.

Listener questions: using a Tempo Trainer in swimming

51:03 -

• The Tempo Trainer is essentially a waterproof metronome. It sits best tucked under the cap rather than clipped to the goggles, and it operates in two main modes.
• The first is stroke rate mode, where it beeps with each stroke cycle to help maintain a consistent cadence.
• The second, and arguably more useful for most triathletes, is a timed interval mode where it beeps at a set duration, allowing the swimmer to use each beep as a wall-turn cue to monitor pace within a rep.
• If you want to hold 1:42 per 100 in a 25-metre pool, setting it to beep every 25.5 seconds means that hitting the wall on each beep confirms you are exactly on pace.
• On the question of changing rest times, the reset button handles this cleanly. Pressing it at the moment of push-off restarts the interval, so the beep always aligns with the next wall regardless of how long the rest was.
• For sessions where pace targets vary across reps, such as a build set moving from 1:45 down to 1:40 pace, the practical approach is to set a fixed midpoint and accept that early reps will arrive slightly before the beep and later reps slightly after.
• Constantly adjusting the setting between reps burns energy and attention that is better directed at the swimming itself.
• The pacing application within reps is where the Tempo Trainer delivers the most consistent value in a triathlon context.
• A very common pattern among triathletes is going out too hard in the first one or two lengths of a rep, with pace declining steadily through the rest of it, yet still averaging close to the prescribed time at the end.
• That is not good execution. Using the timed beep mode imposes accountability for intra-rep pacing and makes the deterioration visible in a way that average split times do not.
• On stroke rate specifically, the more important goal in a triathlon setting is maintaining rate across a rep rather than working up to a higher absolute number.
• The same front-loaded pattern seen in pacing tends to appear in stroke rate as well: the first lengths feel comfortable to hold, and then it quietly drops.
• A higher stroke rate in open water relative to the pool is natural given choppier conditions, but it should emerge organically rather than being artificially imposed.
• One useful application for open water is establishing your natural threshold stroke rate in the pool first, by experimenting with the Tempo Trainer until the beep matches your actual stroke cadence at that intensity.
• If that turns out to be 70 strokes per minute in the pool, setting the Tempo Trainer to 72 in open water sessions gives you a concrete target to hold and makes it easier to notice and correct the inevitable drift.
• The Tempo Trainer can also serve a simple timing function in open water structured sessions, set to beep every minute so that a three-minute interval can be tracked by counting three beeps without needing to check a watch.
• The broader point is that triathletes, even those who push themselves hard on the bike and run, tend to underperform in the pool relative to their actual capacity.
• They are often unfamiliar with what sustained hard swimming feels like, and the Tempo Trainer provides a simple external anchor that allows athletes to commit to a pace and hold it.
• The intensity margins in swimming are narrow, and slightly misjudging the effort causes things to unravel quickly, but once the right level is found, the tool gives you something to hold onto across the full session.

Listener questions: group rides and long-distance race preparation

1:00:32 -

• As a general principle, long rides are always beneficial, and if group riding is what makes big volume accessible mentally, that is a meaningful advantage worth taking seriously. 
• The caveat is that rides of this intensity and duration carry a high training stress score, and the question is always whether recovery allows the rest of the week's training to proceed normally. If it does not, the net effect becomes negative.
• For timing within a training cycle, these rides sit more naturally in earlier phases of preparation.
• In the final six to eight weeks before a full-distance race, the priority shifts toward long time trial efforts that replicate race demands and intensity, which is a different stimulus from a hard group ride with variable efforts. 
• One or two group rides in that final period is reasonable, but they should not dominate it.
• In terms of frequency across the broader build, every other week to every three or four weeks is a more manageable cadence than weekly repetition, and placing the ride on the Sunday before a scheduled deload week is a practical way to absorb the extra fatigue without compromising a full training block.
• The other important consideration is the starting point. Moving directly from steady three-hour Zone 2 efforts to a 200-kilometre hard group ride is too large a jump and will leave residual fatigue that disrupts training for several days afterwards.
• The base needs to include long rides with some form of intensity, whether threshold or sweet spot work, so that the step up to a harder group ride is manageable rather than overwhelming.
• If the group ride is what significantly motivates more volume than would otherwise happen on a solo weekend ride, that motivation factor shifts the calculation.
• The additional training load from the longer, harder ride may justify accepting a slightly compromised recovery day in exchange.

Listener questions: sequencing runs and rides when building running durability

1:05:39 -

• The first step is to work with a sports physiotherapist with experience in elite sport, who can provide a return-to-load plan specific to the injury and the individual. 
• Beyond that, the most important general principle is that the length of the longest run carries more injury risk than total weekly running volume.
• Higher frequency of shorter runs is a safer way to accumulate load than stretching a single long run, which places disproportionate stress on structures that are not yet conditioned for it.
• Intensity should stay easy to start, with run-walk intervals a sensible tool to keep stress genuinely low. Most cardiovascular volume can be covered on the bike while running durability is being built gradually, and there is no need to rush that process.
• Incline treadmill work is a useful way to add specificity and intensity without the same impact loading that road running produces.
• On the sequencing question, for sessions on separate days, the distinction matters less than it might seem. If bike sessions are appropriately easy, the residual fatigue carried into the next day's run should not be enough to compromise form or create meaningful additional injury risk.
• Running on moderately tired legs at easy intensity is acceptable; running with compromised form is not, and that is the line to monitor.
• Within the same day, if there is a free choice, running in the morning and cycling in the evening offers a marginal advantage, but it is not a decision of major consequence.
• For brick runs after long rides, 15 minutes is a fine duration at this stage of development, but fuelling the ride well beforehand is essential.
• Athletes from swimming backgrounds often underestimate nutritional demands in training because fuelling is rarely emphasised in the pool.
• Coming into any run, and particularly a brick run, with depleted glycogen is an unnecessary risk, and for an athlete managing a stress injury history, it becomes a more significant concern.

Rapid-fire questions

Guiding vs middle-distance training on the bike

1:10:52 -

• Base training is broadly similar between the two, but the surging power profile of sprint distance racing means that lactate production, lactate tolerance, and higher intensity work need to be incorporated more specifically. That shift in emphasis becomes the focus in roughly the final six weeks before a race.

Hypoxic training for triathletes

• For triathletes, classic hypoxic training has little merit. Even within swimming, the evidence base is weak and the safety risks are real, particularly when hyperventilation is involved.
• Hyperventilating before underwater work drives down CO2 to the point where the body no longer reliably signals dangerously low oxygen levels, which is the mechanism behind shallow water blackout.
• Breath-holding without prior hyperventilation is meaningfully safer, though competitive distance breath-holding is still not something worth pursuing.
• Extended breathing patterns in the pool, every four, five, or seven strokes, do have a place in triathlon swimming and are reasonable to include if done sensibly and without resisting the urge to breathe.
• One area with genuinely interesting research findings is repeated sprint training in hypoxia, where short all-out efforts are performed with a mask delivering a hypoxic air mixture equivalent to 2,500 to 3,500 metres of altitude at sea level partial pressure.
• In swimming, this is typically structured as three rounds of five by 15-metre sprints with 20 seconds rest, with easy swimming between sets.
• The effects appear most pronounced for 100 to 200-metre swimmers, and equivalent research exists in cycling and running. It is more of a research-context tool than a practical one for most athletes, given the equipment requirements, but it is worth knowing about.

Long run structure for completion-oriented Ironman athletes

• For an athlete whose 30-kilometre run takes four hours, the long run should be structured by time rather than distance.
• A ceiling of around two hours 45 minutes to three hours is appropriate for Ironman preparation.
• Unlike a standalone marathon build, where getting the distance in carries more weight, Ironman preparation places less emphasis on matching race-distance running in training, and three hours at easy effort delivers a meaningful stimulus without the disproportionate recovery cost of a four-hour effort.

Can a high-volume runner transition to triathlon in eight weeks?

• The aerobic base is clearly there, and the run, which carries the highest injury risk when volume is added quickly, is already well established. The main task is building swim and bike volume on top of a strong foundation.

Super trainers during training: are they worth avoiding?

• There is no strong reason to avoid super shoes in training, but it is worth building up meaningful time in them before race day, since they can subtly alter running mechanics and the muscular demands on the foot and lower leg.
• In a base training phase, shoe choice is largely inconsequential. Running slightly slower in standard trainers or slightly faster in super shoes both produce valid training stimuli.

Starting triathlon training when overweight and unfit

• Start small and prioritise consistency above everything else. The instinct to calibrate training against race-day distances is a common mistake at this stage and not a useful way to think about early training.
• A six-week block of consistent, progressive work is the first meaningful unit to aim for, with particular care taken around running volume given the injury risk.
• Alongside the endurance work, maintaining some strength training is worthwhile to ensure that any weight lost comes predominantly from fat rather than lean muscle mass, supported by adequate protein intake.

• Triathlon Base Training Series 5 – Strength Training, Nutrition & Diet, and Listener Q&A - further details to the strength training question asked in this episode
• Metabolic cost of level, uphill, and downhill running in highly cushioned shoes with carbon-fiber plates - Whiting et. al 2022
• Dustin Joubert, PhD & Dr. Amol Saxena, DPM | EP#383 - the importance of gradually building up use of super shoes
• Shallow Water Blackout - by Swimming Canada 
• Effects of Swimming-Specific Repeated-Sprint Training in Hypoxia Training in Swimmers - Camacho-Cardenosa et al. 2020
• Repeated Sprint Training in Hypoxia Induced by Voluntary Hypoventilation in Swimming - Trincat et al. 2016