Go faster to get faster. Sounds appropriate, right? The short answer is yes. The long answer, however, is more complicated.

I recently listened to a podcast interview with Mark Sisson, a former elite runner and triathlete who retired early after succumbing to poor health and injury. He also revamped his training program to include more rest and interval workouts.

In Sisson’s heyday, it was believed that training more equaled training better. But what wasn’t emphasized was the quality of those miles and how to maximize the time spent training for optimal performance. Workouts were focused on maximizing distance and time rather than boosting particular aspects of the cardiovascular system.

“I was performing well, but I was falling apart on the inside,” Sisson explained on the podcast. He retired at the age of 29—early for an endurance athlete, whose peak would normally occur in the mid-30s.

After retirement, Sisson, who also created the popular health and fitness blog marksdailyapple.com, changed his routine to find ways to remain strong, healthy and fit without having to “put so much effort and time into getting there.” His training strategy became less concerned with putting in the time and instead focused on changing the intensity. By adding one to two high-intensity workouts per week, Sisson discovered he could effectively maintain his strength and fitness.

“I can stay as fit or fitter than I was when I was racing,” he said.

In cycling, this is as true as in any endurance sport. You have to put in hard effort to reap the benefit of getting stronger and faster.

Keep this one rule in mind: Your intervals are going to be hard. If they don’t feel really challenging, you’re not going hard enough. As my triathlete husband likes to say, intervals should make you feel like you never want to do that workout again, ever, in your life.

But you get over it, and you will do it again, because you will quickly notice improvement in your strength and stamina.

If you’re training with a heart-rate monitor or a power meter, you’ll want to be in low zone 4 for your hard intervals.

Here’s a sample 60-minute workout that is great for those who have already developed a solid base fitness:

Cycle for 30 minutes easy (zone 2)

Toward the end of the 30 minutes, start ramping up the effort into zone 3.

Minutes 30-35: Crank it up to zone 4.

Minutes 35-40: Do an easy recovery spin.

Minutes 40-45: Zone 4.

Minutes 45-50: Do an easy recovery spin.

Minutes 50-55: Zone 4.

Minutes 55-60: Do an easy recovery spin.

As fitness improves, more intervals can be added the time of the intervals can be increased by 10 seconds. I find that five-minute intervals are long enough to get the heart rate up and sustain it for a prolonged effort.

Intervals can be done on the bike trainer or on the road. If you do go outside for the workout, find a road that is long and flat and without signal lights that will interrupt your efforts.

Keep track of your progress to notice how quickly your bike fitness improves.