Just Enough with The Tweener: Sometimes you don’t need to go all out for 20-60min. The Tweener is often the ‘sweet’ place to be.
The Tweener is that ‘sweet spot’ between Zone 3 and Zone 4 (88-94% ftp), so it’s a little bit of both It often, and should, feel like you could push harder. You won’t feel completely taxed, but you will feel like you have done some good work. More importantly, you will have accomplished something physiologically.
The function of doing Tweener intervals is at least 3 fold. 1) It’s a good area to get used to pacing. Pacing is an important thing to learn when doing any interval. Both Tweener and Threshold efforts can be performed anywhere from 10-30min. Building from a lower effort often helps individuals learn how to pace so they don’t blow up too early; 2) The Tweener works well with base training and the re-building phase during mid-season. As it takes some time for the body to build up its endurance and intensity, the Tweener is a great way to prep the body for future, harder efforts; 3) The Tweener is also great for increasing your Threshold. This may seem counter-intuitive, but you can increase your Threshold in part by doing efforts just below Threshold.
Best of all, it will confuse your friends who are always (or at least Facebook-posting that they are always) hammering somewhere. Incorporating the Tweener into your workouts early in the season will befuddle your pals, increase your power, and increase your confidence when enduring 20min zone 4 efforts. It’s as if you are going just fast enough to get faster, but not going as fast as you think you have to. Try them on for size and watch your power grow.