By Coach John Hughes
I’m enjoying spring riding in Boulder, Colorado where I live. The fields are just starting to get green and beyond them the Rockies are still snow covered. And I have time to enjoy the scenery because I’m not staring at numbers on a heart rate monitor or power meter. I listen to my body and ride by Rate of Perceived Exertion (RPE).
Perceived exertion means paying attention to the signals that your body is sending you: how fast and deeply you are breathing, how hard your heart is beating, how powerfully your muscles are contracting, etc. According to the American College of Sports Medicine there is a reasonably linear relationship between RPE and oxygen uptake and heart rate so RPE provides meaningful feedback.
One year I coached two riders for the solo Race Across America (RAAM). One rider used a heart rate monitor (HRM) and carefully stayed within the prescribed zones training and racing. The other rider just listened to his body. After racing 3,000 miles they finished fourth and fifth. A 60 year old client only used a heart rate monitor for his intensity workouts and RPE for his endurance and recovery rides. He was the first age 60+ rider to finish solo RAAM.
RPE is simple. You don’t have to interpret numbers and remember training zones. RPE is also safer and more fun. You can look at the road and scenery instead of figures on a gadget.
RPE is reliable. One of my clients Ted was riding with a buddy. Ted’s HRM starting picking up his buddy’s heart rate and Ted couldn’t get it to switch back to Ted’s heart rate. Batteries go out and equipment sometimes fails, so even if you use a heart rate monitor or power meter, knowing how to use RPE is a good back up.
RPE is free. You don’t need to pay for anything.
RPE is accurate. Heart rate doesn’t measure how hard your muscles are working. It measures how hard your heart is beating to supply oxygen and nutrients to your muscles. Because RPE gauges how hard your muscles actually are working it may be more accurate. For example, during a longer ride your heart fatigues and doesn’t pump quite as much blood per beat. To maintain the same supply of blood to your muscles your heart has to beat faster so your heart rate monitor reads higher. But you aren’t actually riding harder.
RPE is instantaneous. You can feel immediately how hard you are working. If you are doing any kind of riding that involves training at different intensities when you change the intensity, e.g., starting an interval, the change in your heart rate lags the change in intensity. The sensations from your legs change immediately. Similarly when you stop the hard effort your heart rate doesn’t drop immediately.
RPEs are comparable. You’re riding with a woman who is a good friend. Her heart rate is 165 bpm (or her Functional Threshold Power is 150 watts). Your heart rate is only 140 bpm (or your power only 135 watts). If you’re both breathing deeply but can still talk in full sentences then you’re both working at the same intensity.
RPE for multi-sport athletes. Your lactate threshold changes depending on your sport so you have even more training zones. How your body feels at different levels of exertion is the same across different sports.
RPE is better than a heart rate monitor. Your heart rate can be affected by variables other than how hard you are riding: excitement, heat, dehydration, and how well you slept all affect heart rate. If you are on a medication that alters how your heart responds to physical stress, then heart rate is also not a reliable indicator.
Using RPE to Train
The key to effective training is training at the right intensities and varying the intensity, depending on the purpose of the workout.
I use six different RPEs. Some sports scientists use a 10-point scale where 1 is barely moving and 10 is a flat-out sprint that you can only hold for a few seconds. Here’s my system. Because human power production is a continuum, the different paces and RPEs blend into each other.
- Digestion pace: This is how you’d ride after a big breakfast or lunch, an RPE of 1 – 2. This is the pace for active recovery rides.
- Conversation pace: You can carry on a conversation in full sentences, an RPE of 2 – 3. This pace builds endurance and trains the aerobicsystem to burn fat more efficiently.
- Hill climbing and headwind pace: You’re on a long, steady grade or riding into the wind. You’re working hard enough that you can’t whistle but still talk in short sentences, an RPE of 3 – 4. At this pace you’re improving your cruising speed and training the aerobic system to burn glycogen.
- Sub-barf pace: You’re making a hard, sustained effort, an RPE of 5 – 6. This is the pace for a 20-40 km time trial or hill climb. You’re riding anaerobically to train the lactate system to burn glycogen without enough oxygen—we all know that feeling.
- Barf pace: The classic hammering pace, a hard effort for 5 – 10 minutes —any longer and you’d barf. An RPE of 6 – 7. You’re training to stay with the group when they put the hammer down.
- Eyeballs out pace: Riding as hard as you can for only a few minutes with your eyes bugging out. RPE of 8+ You’re training to increase the maximum amount of oxygen you can deliver to your muscles, your VO2 max.
Learning to Use RPE
I encourage my clients who want to train without a heart rate monitor or power meter to start training with one to get objective data to correlate with their subjective feelings. Here are the heart rate and power equivalents to my RPE.
- Digestion pace (RPE 1 – 2): < 68% of Lactate Threshold (LT), < 55% of Functional Threshold Power (FTP).
- Conversation pace (RPE 2 – 3): 69 – 83% of LT, 56 – 75% of FTP.
- Hill climbing and headwind pace (RPE 3 – 4): 84 – 94% of LT, 76 – 90% of FTP.
- Sub-barf pace (RPE 5 – 6): 95 – 100% of LT, 91 – 100% of FTP.
- Barf pace (RPE 6 – 7): 101 – 105% of LT, 101 – 105% of FTP.
- Eyeballs out pace (RPE 8+): > 105% of LT, 106 – 120% of FTP.
How to gauge intensity depends on your goals. If you are riding for recreation, then you don’t have to use a heart rate monitor or power meter even if you want to improve. If you compete or are trying for major improvement gains, then objective feedback is may be helpful.
Although quantitative feedback is helpful, it’s not essential. How to gauge intensity also depends on who you are. Two friends were training for four-man team RAAM. In team RAAM one rider rides flat out for 15 to 30 minutes while his teammate rests. Then the second rider races while the first rider rests. One rider conscientiously trained by doing intervals by heart rate. The other rider listened to his body and hammered local hills. They were equally fast and their team set a RAAM record!
Some people like data and keep extensive training logs, some people don’t care for numbers. If data are useful to you then you may want to use a heart monitor or power meter.
To learn how best to use intensity training get my eArticle on Intensity Training: Using Perceived Exertion, a Heart Rate Monitor or a Power Meter to Maximize Training Effectiveness. Intensity Training explains in detail the human body produces power and how to gauge your intensities. Based on your personal objectives it describes a dozen different types of workouts with examples of each type of workout. The 41-page Intensity Training is $4.99.