Okay, we know that interval training isn't enjoyable for most riders. They hate working hard by themselves. But intense training is the most effective producer of top fitness, and intervals are about as intense as training gets.
Fortunately, intervals don't need to be solo. You can do them with a training partner even if your speeds aren't well matched. Here's how:
Warm up and then draft your friend. Ease off to let her open a gap of 100-200 meters. While she keeps a steady, moderate pace, ride hard to catch her. Once you do, spin easily in her draft for a minute to recover.
Now take the front position. She does her interval by riding like you just did.
What if you're much slower than your partner? Simply adjust the size of the gap. For example, start your chase when she's 100 meters ahead. She begins her chase after letting you open a gap of 300 meters.
The workout is over when each rider has chased 5-8 times. You'll find that these intervals are lot more fun because you have a "rabbit" to catch, motivation to keep the intensity high and someone to appreciate your effort.
Source: RBR