2024 Ironman Texas Training Review

It has been a great 16 weeks training for Ironman Texas coming up next week. One small injury (foot) from either running or pushing too hard off the wall while swimming. Some interesting stats through these training blocks:

Longest week: 18 hours
Max CTL: 116
Max TSS: 144
Cumulative Miles: 2161
3 week blocks, with 1 week rest. 2 week taper into the race.

Compared with past Ironman races, used the sauna during the last 3 weeks to get more heat adapted, and did a little more strength based workouts. (Not tracked in Intervals). I also focused more on Z2 efforts while running. The Oak Island Half Marathon got me running a lot more early season. Overall, I had some good PR’s during the last 4 months: read more

Cycling: FTP over time

Tracking cycling endurance training progress over time. As I have shifted my focus from MTB racing to Endurance/long distance triathlon, My sprint power has decreased slightly (5 minutes and 1 minute) but FTP (20 min+) has slowly been ticking upward. Since I have been swimming and running more, it probably has not increased as much as I hoped, but I am learning endurance is not something that gets established overnight ….

Is Hypoxanthine the future for monitoring endurance performance?

Super interesting article on the use of Hypoxanthine (from sweat) being used as a predictor of performance in athletes.

Having done HR tracking, Power and over the last couple of years, Lactate, it’s always interesting to hear of new methods and advancements in performance, and opportunities to improve metabolic health. So while I am still waiting for a reasonable/practical real-time Lactate monitoring solution, maybe I should skip to the next big thing …

Check it out here: https://pubmed.ncbi.nlm.nih.gov/23670363/


Purine metabolism reflects the exercise-induced muscle adaptations and training status. This study evaluated the utility of plasma hypoxanthine in the prediction of actual sport performance. We studied male athletes: 28 triathletes (21.4±2.9 years), 12 long-distance runners (23.2±1.9 years), 13 middle-distance runners (22.9±1.8 years) and 18 sprinters (22.0±2.7 years). Season-best race times were considered, achieved over standard triathlon, 5 000 m, 1 500 m and 100 m, respectively. Incremental treadmill test was administered to determine maximum and “threshold” oxygen uptake. Resting and post-exercise plasma concentrations of hypoxanthine, xanthine, uric acid and lactate were measured as well as resting erythrocyte hypoxanthine-guanine phosphoribosyltransferase activity. Simple and multiple regression analyses were used to identify significant contributors to the variance in performance. Hypoxanthine considered alone explained more variance in triathletes, long-distance runners, middle-distance runners and sprinters (r 2=0.81, 0.81, 0.88 and 0.78, respectively) than models based on aerobic capacity and lactate (R 2=0.51, 0.37, 0.59 and 0.31, respectively). Combining purine metabolites and cardiorespiratory variables resulted in the best prediction (R 2=0.86, 0.93, 0.93 and 0.91; r=0.93, 0.96, 0.96 and 0.95, respectively). In summary, hypoxanthine is a strong predictor of performance in highly trained athletes and its prediction ability is very high regardless of sport specialization, spanning the continuum from speed-power to endurance disciplines. read more

Endurance Racing – Sweat Analysis

Sweat, and specifically Sodium, is one of the three “levers” for endurance athletes when it comes to hydration and nutrition (fueling) and subsequently your performance. The other two key elements or levers are Carbohydrates and Fluids.

The most important part about sodium/sweat is that everyone has a unique sweat loss rate, and a unique sodium content ratio in their sweat. So while a more generalized approach can be defined for consuming carbohydrates, the same is not true for electrolyte loss. This is why having a sweat test is critical for athletes wanting to perform, understand and take advantage of their data to understand their personal needs and requirements. read more

Running Notes


Zone 1: Less than 85% of LTHR – 136

Zone 2: 85–89% of LTHR – 136 – 143

Zone 3: 90–94% of LTHR – 144 – 150

Zone 4: 95–99% of LTHR – 151 – 158

Zone 5a: 100–102% of LTHR – 159 – 163

Zone 5b: 103–106% of LTHR – 163 – 170

Zone 5c: More than 106% of LTHR – 170+

Swim Technique Notes

  • Rotate body to gain more reach
  • use hand and arm to catch the water
  • Keep shoulders down/low and use lats , not shoulder to pull
  • Start slow and get faster with pull
  • pull all the way down past waist
  • Breathing:
    • keep one google eye in water, one out
    Think about making your body as long as possible with timing


    • Rotation
      • kick, check rotation, arms at side
      • rotate kits and shoulders, everything in sync
      • 6 kicks one side, 6 kicks flat, 6 on left side
      One arm forward with fins on
      • Swim on side, like superman, make sure body is parallel to wall
      • try to breath
      Skull Drill
      • Use just your hands and work in a small figure 8 rotation to propel yourself down the pool (probably very slowly)