May is here, which means the race season has officially started for most of you. IRONMAN Texas wrapped two weeks ago. Chattanooga 70.3 is May 17. The first half of the year is starting to matter in a real way.
This issue covers what I'm seeing in the data and the field right now: the AI-versus-physiology debate that's happening across coaching platforms and what it actually means for how you train, a session structure built around off-the-bike run pacing — one of the most undertrained skills in triathlon — and a look at how heat changes your fueling equation as summer approaches. Plus a full Five Cornerstones course breakdown for IRONMAN 70.3 Chattanooga, linked at the bottom of Race Intel.
As always — race smart. Own your numbers. The rest takes care of itself.
The conversation around AI coaching platforms has reached a point where it's worth saying something direct: the technology is genuinely useful, and it is also genuinely incomplete. Those two things are both true at the same time.
What adaptive platforms do well is load management. They're good at adjusting volume and intensity based on fatigue signals, missed sessions, and workout completion data. They're good at pattern recognition across large populations. They're increasingly good at flagging red flags before athletes consciously notice them. That's real value.
What they can't do — yet — is tell you what your physiology actually is. They don't know whether you're a high-CP, low-aerobic-capacity athlete who responds to intensity blocks, or a naturally aerobic athlete who needs extended base work before intensity pays off. They don't know where your Metabolic Curve breaks, where your fiber recruitment shifts, or which of the four archetypes you actually belong to. They're working from training load data. That's not the same thing as a physiological profile.
Why This Matters Practically
An algorithm built on population averages will prescribe training that's appropriate for the average athlete. Most athletes aren't average. They're a specific type with specific limiters. CP/CS testing and physiological profiling give a coach — or a system — something real to work with. Without it, you're fitting the athlete to the plan. The plan should fit the athlete.
What to Actually Do With This
If you're using an AI-based platform and it's working, keep using it. If you feel like your training is generic — like it could belong to anyone. Or, if you are struggling to connect to it, that's the signal. The missing piece is almost always physiological profiling. Know what you are before you decide how to train.
"The algorithm can manage the workload. It still needs to know who it's managing it for."
Most triathletes train the swim, the bike, and the run as three separate sports. They train them well. Then on race day, the run falls apart off the bike — not because the fitness isn't there, but because the pattern of running off a fatigued bike was never trained deliberately.
The research on this is consistent: starting the first kilometer of a triathlon run at standalone race pace or faster produces a significantly slower overall run split than starting 5% slower. Not slightly slower — significantly. The athlete who goes out too hard in the first mile of the run rarely recovers. The athlete who starts slightly too conservatively usually runs the back half of the race well.
The problem is that 5% slower off the bike feels extremely slow. Your heart rate is elevated, your legs feel strange, your adrenaline is high, and every competitive instinct you have tells you to run. The session below trains you to override that instinct with data, not willpower.
Setup: This is a brick. Bike first, run immediately after with race-simulation transitions.
Bike: 45–60 min at race-effort intensity (75–82% CP for 70.3 athletes). Not easy, not a warm-up — race effort.
Run — Phase 1 (miles 1–2): 5% slower than your target race run pace. This should feel uncomfortably easy. That's correct. Use a GPS watch and hold the number regardless of feel.
Run — Phase 2 (miles 3–5): Settle into race pace. You should feel locked in by mile 3.
Run — Phase 3 (final mile): Build. Finish faster than you started.
Perform once per week during race-specific build blocks. The goal isn't fitness — it's training the controlled start as an automatic behavior, not a decision you have to make under pressure on race day.
Why the Controlled Start Matters More in Heat
In warm race conditions — which covers every May or summer event in the eastern US — elevated core temperature further impairs off-the-bike run economy. The physiological argument for starting conservatively is even stronger in the heat. A well-executed start keeps heart rate manageable, preserves glycogen, and allows the fueling you've been executing all day to actually absorb. An aggressive start in heat triggers a cascade that's very difficult to reverse.
The data on pre-race anxiety and performance is clearer than most athletes realize. Elevated pre-competition anxiety — both cognitive (what you're thinking) and somatic (what your body is doing with it) — is directly associated with reduced athletic output. Not correlated. Directly associated. Research suggests anxiety-related performance decrements can be equivalent to being undertrained by 10–15%.
Put that in context: the athlete who spent months worrying about missed workouts may have been better served spending that energy managing pre-race cortisol. The fitness gap from a few skipped sessions is usually smaller than the performance tax from arriving at the start line in a high-anxiety state.
What's Actually Happening
Pre-race anxiety is a cortisol response. Cortisol is useful in short bursts — it sharpens focus and primes the body for effort. The problem is duration. An athlete who enters the anxiety spiral on Thursday before a Sunday race and sustains it through race morning has been metabolically taxed for three days before the gun goes off. Decision-making degrades. Early pacing discipline erodes. The ability to hold a plan when conditions get hard diminishes.
The goal isn't to eliminate pre-race activation — some is beneficial and normal. The goal is calibration: keeping arousal in the performance zone rather than the red zone. That's a trainable skill, not a personality trait.
Three Things That Actually Work
Pre-loaded cue words. Before race week, identify 2–3 single words that bring you back to your execution plan when anxiety spikes. Use them in hard training sessions first so they're automatic by race day — not something you're inventing under pressure at the start line.
Process anchoring. The anxiety spiral almost always starts with outcome thinking: what if I blow up, what if my pacing is wrong, what if I don't hit my goal. The counter is explicit process focus — what am I doing in the first mile of the run, what's my sodium target on the bike, what's my first checkpoint. Process questions crowd out outcome anxiety in a way that willpower alone doesn't.
Sleep prioritization — two nights out. The night before a race is often poor sleep regardless of anxiety. That's fine — research shows one night of poor sleep has minimal impact on physiological performance. What matters more is the night before the night before. Prioritize sleep Thursday for a Sunday race. That's where the real physiological restoration happens.
"Some activation is useful. The goal is calibration — keeping arousal in the performance zone, not the red zone. That requires skills, not motivation."
IRONMAN 70.3 Chattanooga runs May 17 — thirteen days from this issue. If you're racing, race week check-in opens Friday May 15 at Ross's Landing. Bike check-in is mandatory Saturday May 16, 10 AM to 5 PM. There is no athlete check-in on race morning.
The course is fair. Downstream swim in the Tennessee River, 56-mile rolling bike through north Georgia, two-lap run through downtown Chattanooga finishing at Ross's Landing. The bike has 2,218 feet of climbing. The run has 627 feet of gain across 13.1 miles — more than athletes expect from a riverfront course. The May humidity, if it shows up, will make the run feel like more.
What This Race Punishes
Chattanooga is unusually good at exposing three specific execution errors: athletes who ride the first 25 miles of the bike too hard because they feel good, athletes whose fueling plan was built for cooler conditions and collapses under heat stress, and athletes who launch the first mile of the run off an adrenaline surge and spend the second lap grinding through the consequences. All three are avoidable with a specific plan executed with discipline.
What This Race Rewards
Consistent power on the bike. A controlled off-the-bike run start. A fueling plan that's been tested in warm conditions. And patience — the kind that doesn't feel like a strategy until mile 10 of the run, when every athlete around you who didn't have it starts to fall apart.