Cycling for triathlon demands a completely different mindset from pure cycling events — every watt you burn on the bike comes directly at the cost of your run. Getting the bike leg right means mastering your aero position, pacing conservatively enough to run well, nailing your nutrition, and training transitions with dedicated brick workouts.
Aero Position: Speed Without Blowing Up
An aerodynamic position on a triathlon or time trial bike can save 20–40 watts at race pace compared with a standard road bike position. That is free speed — but only if you can hold the position without compromising your power output or destroying your legs for the run.
The key dimensions for a triathlon aero position are: a steeper seat tube angle (76–78°) that rotates the hips forward and spares the hip flexors for running; elbow pads shoulder-width apart; and a low, narrow frontal profile. Crucially, your position must be sustainable. Practise holding it for the full race distance in training. If you cannot hold it after 60 minutes, it is too aggressive for your current flexibility and core strength.
Pacing the Bike Leg for a Strong Run
Most age-group triathletes ride too hard and pay for it with a death-march run. The bike leg in triathlon should feel deceptively easy. Power-based pacing is the gold standard.
| Distance | Recommended Intensity | RPE (1–10) |
|---|---|---|
| Sprint | 85–95 % FTP | 7–8 |
| Olympic | 78–88 % FTP | 6–7 |
| Half-Ironman (70.3) | 72–82 % FTP | 5–6 |
| Ironman | 65–75 % FTP | 4–5 |
Brick Workouts: Training Bike-to-Run Transitions
A brick workout combines a bike session immediately followed by a run, replicating the heavy, wooden feeling in the legs that every triathlete knows from the first kilometre of the run leg. The name "brick" is said to come from exactly that sensation.
Tip: Start with short bricks — 30-minute ride followed by a 10-minute run — done once a week. Gradually build the bike duration and the run duration over your training block. The transition feeling becomes less severe as your neuromuscular system adapts to the bike-run sequence.
Key brick formats include: long brick (race-distance bike followed by 20–30 minute run), sprint brick (high-intensity short intervals on the bike followed by tempo run), and T2 practice (multiple short bike-run pairs to drill the transition routine itself).
On-Bike Nutrition Strategy
The bike leg is your best opportunity to fuel for the run because eating is far easier on the bike than during the run. Aim for 60–90 g of carbohydrate per hour using a mix of glucose and fructose sources, which allows higher absorption rates than glucose alone. Liquid calories (sports drinks, gels washed down with water) are easier to consume at speed than solid food.
Practise your exact race nutrition in training — never try new products on race day. Time your last gel to be taken 20–30 minutes before T2 so it is absorbed before you start running. For broader endurance training principles that underpin triathlon performance, read our Complete Guide to Cycling Endurance.
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Try PaceOverlay Free →Frequently Asked Questions
Do I need a triathlon-specific bike?
No — especially not for your first triathlon. A road bike works perfectly well for sprint and Olympic distances. A triathlon or time trial bike with clip-on aero bars becomes worthwhile when you are consistently finishing in the top half of your age group and riding half-Ironman or longer distances. Bike fit matters far more than bike type at the beginner to intermediate level.
How do I avoid cramping on the run after the bike?
Cramping is usually caused by a combination of pacing too hard on the bike, inadequate sodium intake, and poor heat acclimatisation. Race at the recommended intensity, take sodium via electrolyte drinks or salt capsules (300–500 mg/hour in hot conditions), and train in conditions similar to your race environment in the weeks before the event.
What is the best way to practise T2 transitions?
Set up your transition area at home or at the track and rehearse the exact sequence repeatedly: rack bike, remove helmet, rack helmet, put on running shoes, grab race belt, go. Aim to complete T2 in under 90 seconds. Mental rehearsal — visualising the sequence in detail before sleep — also measurably reduces transition times on race day.
Final Thoughts
Mastering cycling for triathlon takes deliberate practice, but the payoff — better efficiency, higher power output, and more enjoyment on the bike — is worth every session. The guidance here on Aero Position: Speed Without Blowing Up, Pacing the Bike Leg for a Strong Run gives you a solid foundation to build from.
Apply one or two takeaways from this guide on your next ride. Small, consistent improvements compound into significant gains over a season. Stay patient, trust the process, and enjoy the journey.