Tempo intervals are some of my favorite workouts to improve power at lactate threshold. I use some form of these intervals for nearly every level of cyclist at every distance of recreational or competitive event.
For a beginner cyclist with only three or four months to prepare for a distance ride or race, tempo intervals will fall near the end of the training cycle in the few weeks before the event.
For more experienced cyclists with a high level of fitness, I use tempo intervals as one of the first workout building blocks to improve lactate threshold speed and power. These cyclists will often do tempo intervals within the first few weeks of a foundation fitness phase of training before moving on to threshold intervals and anaerobic intervals.
Even if you are not training for a specific event, you can use these intervals to improve your fitness.
For this column, I will use power as the intensity measure for the intervals, but I will still integrate heart rate. Many of you have power available on your bike, home trainer or on the Spin® bike at your local gym. Before your baseline test, you will need to have established your training zones. (Use this document as a reference chart for cycling.)
With training zones established, the first thing you need to do is get a baseline measure of your current fitness.
- Warm up for 20 to 30 minutes, keeping heart rate in Zones 1 to 2.
- Near the end of your warm-up, do 2 x 90 seconds of slowly building power until heart rate reaches your Zone 3 level, taking three minutes to recover after each build interval.
- After your warm-up, ride a 20-minute steady time trial effort, keeping your heart rate within a three beat range at the top of your Zone 3. For example if your Zone 3 heart rate range is 143 to 148, aim to ride the entire time trial within a heart rate range of 146 to 148. It will take you few minutes to get the intensity right, but once you've settled in you can hold this narrow range.
- At the end of the time trial, note your average power output (APO) in watts, average heart rate and distance traveled. You can repeat this time trial again in a few weeks as one measure of fitness improvement.
With your baseline information in hand, here is an example workout aimed at improving your fitness:
- Warm up for 20 to 30 minutes, keeping heart rate mostly in Zones 1 to 2.
- Near the end of the warm-up, do 2-3 x 60 seconds at your APO from the baseline time trial. Take a full three minutes to recover between each effort.
For the main set do:
- 3 x 3 minutes at APO + 10 watts (spin easy for 1 minute between each to recover)
- 3 x 1 minute at APO + 20 watts (spin easy for 30 seconds between each to recover)
- 3 x 1 minute at APO + 30 watts (spin easy for 1 minute between each to recover)
After each of the sets listed, go right to the next set after your recovery interval. Do not take extra rest.
- Cool down for 10 to 20 minutes at Zone 1 heart rate.
Improvement Over Time
With the right mix of workouts and recovery during the next six to eight weeks, you can do a repeat of your baseline time trial and you should see an increase in average power for the same heart rate.
When you do the retest, be sure you use the same bike setup that you used for the original time trial. This is because power systems will vary from one setup to the next and you want your retest as accurate as possible. For systems that have a calibration method, calibrate the power meter before each time trial.
Depending on your training goals and plan, doing some variety of tempo intervals once or twice per week will improve your power output. Once Zone 3 power has stabilized, it is time to move on to the next phase of training for your specific goals.