If you’ve been cycling for any length of time chances are that you’ve heard of Intervals. The word ‘interval’ or ‘intervals’ is usually tossed around while folks are talking about their training. For instance, you might see on DailyMile a cyclist describe their last ride as being 3×8 Intervals at RPE 7 with a 10 minute RBI. Makes perfect sense right? In this post I’m going to explain what Intervals are, the different types, and why they’re good for your riding.
What is an Interval?
If you define the word ‘Interval’ you get:
A definite length of time marked off by two instants.
So, an interval is a period of time that’s marked off by two instants (a start and a stop). Putting all that together we can further deduce that an Interval is a measured period of time marked by a start time and a stop time. The length of the period of time is the Interval. By that definition you could define any ride as an Interval – you know the time you started riding and the time you stopped riding. That would be one Interval. That’s not how we use them though.
In cycling we use the word ‘Intervals’ to define short periods of time (30 seconds to several minutes) over the course of a ride. For instance, you might hear a cyclist say that she performed three eight minute intervals during her workout today. That means that she broke out 24 minutes (3×8=24) as measured periods of time from her overall ride duration. Why did she break out those 24 minutes and what did she do during that time? It wasn’t to do her nails. Keep reading.
Why do Intervals?
There’s a lot of talk about incorporating intervals into our cycling routine but you may be wondering why. It’s a good question because intervals can be an important part of your plan for losing weight, training for a long century ride, or improving your overall riding. Lets look at this in more detail.
- Losing weight. Most of you know that when you ride you burn calories and that burning calories is an important part of losing weight. The amount of calories you burn while cycling is, basically, determined by the pace you ride. I say basically because there are lots of other factors like hills, wind, your metabolism, nutrition, weight, etc., but it all comes back to how much effort you’re putting out while riding. The chart below shows some numbers for how many calories a 150-pound cyclist would burn if riding at the indicated pace for an hour.
So, how do intervals fit in? If a 250-pound cyclist were to ride for one hour at 12-14 mph they would burn 909 calories . If they want to burn more calories per hour they just have to ride faster right? True but what if they can’t maintain that faster pace for an hour? They just ride longer at the slower pace right? True again but what if they don’t have the time to ride for two hours? Some people do have a day job and can’t spend all day on the bike.
This is where the interval helps. By riding for brief periods of time at higher intensities, the cyclist can burn more calories in that single hour. Let’s look at an example.
If the 250-pound cyclist rides for one hour at 12-14 mph they would burn 909 calories.
If, instead, the 250-pound cyclist included 3×8 intervals at a speed of 16-19 mph they would burn an extra 182 calories for a total of 1091 . The breakdown would look like this:
250 pounds @ 12-14 mph for a 10 min warmup = 152 calories
250 pounds @ 16-19 mph for 24 min (3×8 Intervals) = 545 calories
250 pounds @ 12-14 mph for 26 min (RBI+cooldown) = 394 calories
Total = 1091 calories
- Improving riding. The very process of performing intervals will improve your riding. By pushing yourself to a pace beyond what you normally ride, you’re forcing your body to adapt and condition itself to perform at those higher exertion levels. Including intervals as part of your normal training routine forces your body into being able to increase it’s oxygen intake and improves your overall aerobic capacity. I know first hand that they work.
During the summer of 2009 I embarked on a 10-week century training program. This plan included intervals 2-3 times a week with interval durations being in the 6 to 8 minute range. Over the next 10 weeks I saw huge improvements in my cycling that included being able to maintain higher paces for longer periods of time, increased average speed for my rides, and the ability to ride longer and further. I also lost weight.
You can include different types intervals into your training routine to target specific goals like climbing faster and improving your sprinting. It all depends on your goals.
Let’s talk a little bit about how Intervals are to be interpreted when you read about them or someone says:
“Today I did 3×8 Intervals at RPE 7 with a 5 minute RBI.”
Will you actually hear someone say it exactly like that? Probably not as most people will just say that they did three 8-minute intervals. However, if you’re following a training plan, the intervals will most likely be notated like my example which means you need to understand what it all means. Here goes.
Take my example of 3×8, RPE 7, RBI 5. Here’s what it means:
- 3 – this is the number of intervals to be performed.
- 8 – this is the length (usually in minutes) of each interval.
- RPE 7 – this is the Rating of Perceived Exertion (RPE). It’s a scale of 1 to 10 with 1 being the easiest and 10 being the hardest.
- RBI 5 – this is the amount of Recovery Between Intervals (RBI). In this case it’s 5 minutes.
That means you’re going to do 3 intervals. Each interval will be 8 minutes in duration at an exertion level of 7. After intervals 1 and 2 you’ll ride at a recovery pace for 5 minutes. That entire set of intervals will make up 34 minutes of riding time (3 intervals x 8 minutes = 24 minutes + 10 minutes of RBI = 34 minutes). Tack on a 10 minute warmup and 16 minute cooldown and you’ve got a good one hour ride.
I don’t want to get into a long discussion about RPE here so I can save that for a future article. Just understand that it’s a measurement of your perceived effort based on how hard your riding and how easy it is for you to breath under that effort. Other ways to measure it include a heart rate monitor or a power meter.
Types of Intervals
An interval is not an interval. Yeah, they’re spelled the same but they aren’t. Trust me. As cyclists, we have ways we can adjust the intervals besides just length of time and pace. They are:
- Max – These are all out efforts. A 9 or 10 on the RPE scale they, thankfully, only last for very short periods. They’re used to increase your maximum oxygen intake. (2)
- Brisk – A 7 or 8 on the RPE scale, Brisk intervals help raise your lactate threshold so you have a bigger aerobic capacity. Climbing hills and sustained efforts are two ways to perform this interval. (2)
- Ramps – A ramp interval starts at one effort level and transitions to another, higher level, over a period of minutes. (2)
Other types include climbing intervals, resistance intervals, and jump starts. (2)
I’ve only scratched the surface of interval training for cyclists. At their simplest, intervals are short periods of time incorporated into our training that enable us to improve on specific aspects of our cycling be it sprints, climbing, endurance or weight loss.
There are some great cycling books out there that talk about intervals and I’ve listed two below that you should take a look at if you’re interested in learning more or finding a training plan that incorporates intervals.