Train effectively every time by working out your cycling lactate threshold, says coach Phil Mosley.Triathlon Training: Find your biking sweetspot

Each time you ride your bike, do you have a specific session in mind or do you just head out the door and pedal? It’s always worth taking the time to plan your sessions properly, because what you do with your precious riding time will ultimately determine how fast you ride at your next triathlon.

There are various sessions you could do while you’re watching the scenery go by. Long rides at lower intensities can improve your endurance and your ability to utilise fat as a fuel. Short hard efforts can improve your top-end speed by increasing your maximal oxygen uptake. However, there’s one type of training session that is perhaps more relevant for triathletes than either of those – lactate threshold workouts.

This quote from the book Training and Racing with a Power Meter by Hunter Allen and Andrew Coggan, PhD, (Velopress) sums it up best: “Lactate threshold is the single most important physiological determinant of performance for something as short as a 3km pursuit, to a stage race lasting as long as three weeks.”

Learn what lactate threshold is

Lactate threshold (LT) is the exercise intensity at which lactic acid starts to accumulate in your blood stream. Your lactate threshold determines the percentage of your maximal oxygen uptake (or VO2 max) that you can utilise for any given amount of time. In other words, it determines how hard you can ride for a sustained period during a triathlon.

Test your LT

The intensity at which you reach your lactate threshold approximately equates to your best recent performance during a one-hour steady state cycling time trial. You can test this yourself by riding hard, at steady state, for an hour. A better way of doing it is to enter a 25-mile cycle time trial (see for more information). If you have a power meter, you should measure your average power during this test. Your average power (in watts) can be referred to as your functional threshold power (FTP).

Try to measure your average heart rate too, so that you can track progress in both heart rate and power over a period of weeks and months. If you don’t have a power meter, you can do the test measuring just your heart rate. Just be aware that using heart rate for LT training is not as good as combining it with a power meter, but it’ll get the job done.

Train using LT and power

There are two broad types of LT boosting sessions you can do. The first is called sweetspot training, which involves riding at an intensity that equates to 88-94% of your FTP. These workouts give many of the benefits of harder LT training without as much of a fatigue hangover. See ‘Make It Work’ (left) for an example.

The other type of lactate threshold session involves training at 100% of your FTP. This is hard work and you’ll need plenty of recovery between efforts and workouts. Again, there’s an example on the left in the ‘Make It Work’ section.

Train using LT and heart rate

Once you know your approximate one-hour race heart rate, you can do sweetspot (sub-LT) sessions by riding at 5-15 beats below your LT heart rate. Alternatively you can do workouts at 100% of your LT heart rate, but these are more taxing on your body and you’ll need more recovery time. For starters, try our two sessions on the left.


Make it work for you

Sweetspot workout (sub LT)

WU: 15-30mins

MAIN: 5mins at 100% FTP or LT heart rate [HR]; 10mins easy; 20mins at 88-94% FTP or 5-15 beats below LT HR; 10mins easy; 20mins at 88-94%FTP or 5-15 beats below LT HR

WD: 15-30mins

100% Lt Workout
WU: 15-30mins

MAIN: 3mins at 100% FTP or LT HR; 15mins easy; 4x7mins at 100%FTP or LT HR +5mins easy recoveries

WD: 15-30mins

Phil Mosley is coaching editor of Triathlon Plus magazine.