Nutrition PB or Race Tactics Physiology & Anatomy

caffeine for 5k triathlon duathlon improvement

14 September 2014
the5krunner

training-recovery[1]
Source: t-nation.com
Taken from tritalk.co.uk

“Caffeine is one of the few proven ergogenic aids- the current optimum dosage that is needed is 5-mg/kg in the 60-90 minutes pre race or heavy session- the dose response curve flattens out after this. Caffeine is rapidly absorbed from the gut and reaches peak plasma concentrations within 1 hour- the blood half life is 3-6 hours, so shorter races do not need “maintenance doses”

Dose response was done with cyclists given 5,9 and 13mg/kg caffeine and this was the trial that showed no improvement gains above 5mg/kg.

Caffeine has been shown to extend endurance in strenuous aerobic exercise and also improves muscular strength and endurance in prolonged exercise. This has been placebo control trialled. The benefits have been shown to persist up to 5 hours after the initial dose.

Caffeine also theoretically mobilises free fatty acids and increases fat catabolism and reduces carb oxidation, but one study did not demonstrate any increase in plasma FFAs

Studies also done on swimmers doing 1500m trials and showed that each 500m split improved with caffeine and total swim time improved on average by 1.9%, though I am not sure how statistically valid this is.

Running studies have taken ” time to fatigue” and caffeine gave significant duration increases.

Interestingly, one study subjectively demonstrated a reduction in perceived exertion for the same exercise.

Second surge energy gel has 100mg caffeine in it
High 5 Energy Source extreme has 180mg/ sachet
SIS gels have 50mg
High 5 gels have 30mg

Last Updated on 12 January 2026 by the5krunner

My favourite kit and nutrition

  • Maurten — the race nutrition trusted by elite athletes. Gels and drink mix engineered to be easy on the stomach.
  • Garmin 90-degree charging adapter — the small adapter that keeps your charging cable tidy at the stem. Essential for race day.
  • Garmin charging puck — the fastest and most reliable way to top up your Garmin before a session.
  • Ravemen FR300 — front light that mounts directly under your Garmin or Wahoo head unit. Keeps your bars clean and your beam pointed where it matters.
  • Garmin Varia RTL515 — radar rear light that alerts you to vehicles approaching from behind. Pairs with your Edge or Garmin watch.
  • Stryd — the footpod that brings running power to your Garmin. The single most useful running upgrade I have made.
  • Favero Assioma Pro RS2 — the power meter pedals most serious cyclists end up choosing. Accurate, easy to move between bikes.

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