There’s more to a fast bike split than a high sustainable power output and optimised aero position. On race day, you're not riding in a wind tunnel, on an indoor trainer or down a dead-flat road by yourself. Instead you’ll be out there on undulating and technical courses with hundreds or thousands of other competitors, and your cycling fitness has to be up to the challenges of those environment.
A great friend of mine is an uber athlete on the turbo, he trains consistently on his own and has improved his sustainable power output on the bike, but on race day he struggles to find any rhythm on the bike leg. He gets disappointed because between the rolling hills, corners and efforts to pass other riders, he often runs out of steam before T2. He has done a great job increasing his sustainable power but nothing to improve his ability to cope with changes in pace.
You’re never going to be able to sit at a completely steady power output during the bike leg, and it is important to realise that repeated efforts above your lactate threshold lead to fatigue faster than maintaining a more consistent output. At the same time, recent research confirms what’s been anecdotally known for some time: working harder when the going gets tough and recovering when conditions are easier leads to faster times. In other words, it’s a good idea to train for the eventuality that during a race you’ll want to or need to increase your effort above your sustainable output. You will need to recover and then push on again.
The key to gassing it over small climbs, accelerating out of corners and surging to get around competitors—without sapping your long-term strength—is developing the agility to go above your lactate threshold for short periods and then recover without slowing dramatically below your normal race pace. You can do this with a slight variation to a typical threshold interval workout.
3 x 8 minutes at or just below maximum sustainable power output, 6 minutes easy spinning recovery between intervals.
3 x 8 minutes, but instead of staying at or just below maximum sustainable power output, increase intensity by 10-15 percent (250 watts goes to 275-288 watts) for 1 minute every 3 minutes during the interval. Each interval looks like this:
3 minutes maximum sustainable power (MSP)
1 minute MSP plus 10-15 percent
3 maximum sustainable power (MSP)
1 minute MSP plus 10-15 percent
Total: 8 minutes
If you find the harder portions of the intervals are too intense for your current fitness, reduce them to 30 seconds. Stronger riders can include more frequent fluctuations in the intervals, like alternating between 1-2 minutes at maximum sustainable power and 30 seconds to a minute at the higher intensity.
One of the things you’ll notice during these intervals—and during races—is you’re often better off handling short periods of higher intensity by increasing your cadence rather than shifting to a harder gear. Pushing against more resistance in a bigger gear feels like you’re generating more power, but often it just means you’re over-geared and producing less power than before. This is part of the reason I like athletes to think about coping with changes in pace as a matter of agility instead of brute strength. When it’s time to accelerate, think of revving your cadence first, then shift to a bigger gear once you can do it without bogging down. For many short efforts, like making a pass, revving the gear you’re in often allows for a more seamless return to your sustainable rhythm and power output.