Cruise Intervals! Best 30 min workout!

I had 30 minutes this morning and wanted to get in a quality run. I was hoping to spend some time at threshold pace without over doing it. It was similar to last week but shorter intervals and less rest. The workout turned out to be a great quality workout and it was completed in just over 30 minutes.

After a mile warm up I did 5x 1/2 mile at threshold pace with 30 seconds rest in between them and finished with a mile cool down.
My times were 3:10, 3:12, 3:06, 3:06, 3:10 and that 30 seconds rest sure goes by fast after 4 of them.

I finished with 3x150m accels.
The total mileage was 5 miles in 36:05 (avg 7:13 pace).

Cruise Intervals are done at threshold pace, or comfortably hard, 90% vVO2max / Heart rate. The idea is just to break up a longer threshold run to make it a little more manageable. Usually rest should be only 1 min/mile intervals. Jack Daniels recommends no more than 30-60 seconds rest. This short rest keeps lactic acid levels constant. Since I was only doing half mile intervals then my rest was only 30 seconds. In other words I could have run 2.5 miles at 6:20 pace, but breaking it up gave me a short mental break.

If you only have 30 minutes and want a quality workout try this: 8 minute warm up, then 5x (3min comfortably hard followed by 30sec easy), finsh with 8 minute cool down. Total 33:30 workout.


Here is what Jack Daniels, PhD. has to say on cruise intervals:
"Plenty of scientific evidence, not to mention common sense, tells you that you can run longer at a certain pace if you take short rests than you can by running that pace nonstop, as in tempo running. This type of intermittent run/rest approach also reduces the stress level of training. No wonder the concept many years ago gave rise to interval training - probably the world's most popular form of high-level athletic training.

Now the same idea brings us a newer, more effective form of training - cruise intervals. Simply put, cruise intevals are a type of threshold-pace running in which you divide the workout into several segments that are separated by recovery periods. As a result, the lactic acid level in your blood remains quite constant, the same as in a steady tempo run. (I have actually tested this with my runners, and found it to be true even when they were running 6 miles of cruise intervals.)

A typical crusie-interval session should include a warmup, the cruise intervals and a warmdown. I generally recommend the 1-mile distance for cruise intervals but believe that any distance from 1/2 mile to 2 miles (3 minutes to 10 minutes of hard running per interval) would prove equally effective. The short rest between intervals is essential to the workout; it should last only 30 to 60 seconds.

How many cruise intervals can you do on each hard day? The general rule of thumb is that your cruise intervals should total no moare than 8 percent of your total weekly mileage. If you run 20 miles a week, do about 1 1/2 miles of cruise intervals; if you run 50 miles, do about 4 miles. Generally my athletes run just one cruise interval session per week.

Don't let a low or moderate weekly mileage total hold you back. Cruise intervals can prove particularly effective for runners in the 15- to 30- miles-per-week range. For example, a 20-mile-per-week runner might do 3 x 880 yards at threshold pace with 60-second recovery jogs between the 880s. Cruise intervals also make an excellent transition from a steady-running program to one that includes more demanding workouts."

The rest of the article is here. Check it out.

Greg McMillan says of cruise intervals:
"The Cruise Interval workout was popularized by the running coach, Jack Daniels. They, like the other Stamina workouts, are meant to increase your lactate threshold pace. Cruise Intervals are like shorter and slightly more intense tempo intervals. They last three to eight minutes and the pace is between 8K and 12K. Like tempo intervals, they are followed by short recovery jogs (30 seconds to 2 minutes). You'll probably find that it's easy to run too fast on these. The tendency is to treat them like regular long intervals. However, keep it under control and work on a smooth, fast rhythm. Control in training is key to improvement." Read his article here.