The 4x8.

The 4x8 is the best simulation of how you set your pace when climbing in a group. On a steady hill in a perfect world you could set a pace that would keep your heart rate at a fixed rate, and finding your optimal tempo would be easy. The world isn’t perfect, you’re either going too easy and your heart rate is coming down, or you’re going too hard and your heart rate is going up. The 4x8 simulates that by having two speeds:

Sustain - how you lower your heart rate while climbing.  Sustain is glutes isolation, just using your own body weight. Cadence is determined by physics, it’s your body weight falling onto the pedals. As lazy as you can get away with while keeping the pedals turning.

Up-tempo - how you raise your heart rate.  Same technique, it’s all glutes. The difference is you are adding effort by throwing your body weight at the pedals. Technique still counts, timing still counts - raising your heart rate by being less efficient isn’t what we’re after.

That’s it - two speeds.  You’re in sustain (lowering your heart rate) or you’re in up-tempo (raising your heart rate).

There are 4 8-minute segments (thus the name).  The first 8-minute segment is in the 4th hardest gear, the second 8-minute segment is in the 3rd hardest gear, the third 8-minute segment is in the 2nd hardest gear and the last 8-minutes segment is in the hardest gear. For resistance the first 8-minute segment should be just hard enough to support your body weight (it’s a glutes workout), the hardest gear should be hard just to keep moving.

That’s it, shift up a gear every 8 minutes for a total of 32 minutes.

Remember, your goal is to spend the most time in up-tempo in that 32 minutes. That’s the whole workout (if it were only that simple)   Much like climbing a hill with a group, the 4x8 is always an experiment. The results will always change, you will fail to complete a few of them, more to the point, you will learn how not to fail.

You have two speeds, up-tempo and sustain. Use up tempo to raise your heart rate, use sustain to lower it. You have four segments in four gears, the first segment has the least resistance, raising your heart rate is going to take more time, bringing it back down again will be easy. In the last 8 minutes, that will be the other way around–raising your heart rate will happen fast, lowering it is almost impossible. Knowing this, you have to set up a timing plan.

In the first 8 minute segment you need to put as much up-tempo time in the bank as you can. I’m gonna suggest 3 minutes of up-tempo followed by 1 minute of sustain X2 (there will be lots more 4x8s to tweak this).  For the second 8-minute set I will suggest 1:30 up tempo, 30 seconds sustain X4. for the third 8-minute set I’ll suggest 1 minute up-tempo, 1 minute sustain X4. The last 8-minute segment you play by ear.

It won’t take long before you figure out how you can sneak in more up-tempo, but you will also find that front loading the workout will cause you to fail (you’ve just become that guy who attacks at the bottom of the climb).  Your data will show how your heart rate changes based on up-tempo vs sustain. Some people see an almost immediate drop in heart rate when returning to sustain, others take a bit longer. If it takes 20 seconds for your heart rate to start coming down, 30 seconds at sustain can’t be enough. You need to make your timing fit how your body reacts to workload.