

I’ve written previously about the benefits of riding miles at a conversational pace. I’ve also explained that once you’ve built your endurance base in the spring, just riding more miles won’t make you a much better rider. Further, if you’ve been riding for years then just piling on more miles brings little improvement.
Every roadie – from health and fitness riders to high performance racers – can benefit from intensity exercise. Intensity exercise doesn’t mean “no pain, no gain.” It simply means riding harder than you usually ride.
The American College of Sports Medicine recommends that for good health everyone should get at least 2 hours, 30 minutes of moderate aerobic exercise or 60 minutes of vigorous exercise – or a combination of aerobic and vigorous workouts – every week. Moderate means riding at a conversational pace. Vigorous means riding harder — you can still talk in short sentences and your legs aren’t screaming at you. The ACSM also recommends doing more, up to 5:00 hours a week moderate exercise or a combination of less aerobic exercise plus some vigorous exercise.
Why does riding harder help?
Your body has two different types of muscle fibers:
Slow-twitch fibers that contract slowly and generate relatively small forces but have great endurance. These fibers provide the power for activities that require sustained muscular contractions, such as an endurance ride. The harder you ride, the more slow-twitch fibers you activate and train. They are called slow-twitch fibers because of the relatively slow rate at which the fibers contract (not how fast you are spinning).
Fast-twitch fibers generate about twice the force of slow-twitch fibers; however, these fibers are more easily fatigued than slow-twitch fibers. Once you are using all of your slow-twitch fibers, your fast-twitch riders also kick in. These fibers are especially important for exertions that require more force, such as a hard climb or riding into a stiff headwind. These are called fast-twitch fibers because of the relatively fast rate at which the fibers contract.
If you only do endurance riding, you’ll only train your slow-twitch fibers. By doing vigorous riding (riding harder), you’ll also train your fast-twitch fibers.
How is “hard” defined?
Most coaches describe intensities using a hierarchy of different zones. Here’s my system in terms of Rate of Perceived Exertion (RPE), with the intensities ranging from an RPE of 1 up to 10. Your body doesn’t shift gears like a car or your bike, but rather increases power on a continuum, which is why the RPEs overlap.
- Digestion pace: How you ride after a big meal, an RPE of 1-2. This is the pace for active recovery rides.
- Conversation pace: You can easily carry on a conversation in full sentences, an RPE of 2-3. This pace builds endurance.
- Hill climbing and headwind pace: You’re climbing a long, moderate grade or riding into sustained wind. You’re working hard enough that you can’t whistle but can still talk in short sentences, an RPE of 3-4. At this pace you’re improving your cruising speed.
- Power pace: You are riding harder up a relatively short, steeper climb or into a stiff headwind but not yet sub-barf. You can talk in short phrases but not short sentences. An RPE of 4-5.
- 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 racing up a climb.
- Barf pace: This is the classic hammering pace, a hard effort for 5 – 10 minutes — any longer and you’d barf — an RPE of 6-7.
- Eyeballs out pace: Riding as hard as you can for only a few minutes with your eyes practically bugging out, an RPE of 8-9.
- Ouch pace: Sprinting at maximum effort, an RPE of 10.
I also define these paces in terms of heart rate and power. You can download a spreadsheet with my training zones here. You can enter your own lactate threshold or functional threshold power to calculate your personal training zones.

Coach Hughes‘ 39-page eArticle Intensity Training explains the benefits of training by intensity and how to: use perceived exertion, a heart rate monitor or power meter to maximize training effectiveness. To make the article as useful as possible Coach Hughes provides a table with 10 different training objectives. For each objective he gives the proper training zone described in terms of perceived exertion, heart rate and power readings. Each objective is then linked to 5 to 10 specific workouts. Each category of workout includes both structured and unstructured workouts. The article is $4.99.
What’s Right for You?
What’s your normal riding pace? The next harder pace is the initial right pace for your intensity training. Intensity training does not mean no pain, no gain! You don’t have to kill yourself when adding intensity. It just requires stepping up the pace at which you normally ride.
If you currently ride on the flats at a conversational pace (RPE 2-3), then adding riding at the hill climbing/headwind pace (RPE 3-4) will improve your riding. If you can ride at an RPE of 3-4, then incorporating power pace riding (RPE 4-5) will improve your riding. If you normally include power pace riding (RPE 4-5), then stepping up to some sub-barf riding (RPE 5-6) will improve your riding.
Guidelines for Training by Intensity
Every intensity training ride should include a warm-up, a main set and a cool-down.
For the main set, some riders like unstructured intensity rides. I’m one of those riders. For example, ride a course with rolling hills. Ride to the first hill to warm up. As the main part of the workout, climb each hill at the planned intensity and recover until the next climb. After the climbs, then cool down by riding home.
Other riders like more defined, structured intervals. For example, warm up for at least 15 minutes. For the main set repeat 3 to 5 times [5 minutes at an RPE of 4-5 and 3 minutes recovery]. Cool down for at least 15 minutes.
Both unstructured and structured intensity workouts work. Whether you do unstructured or structured intensity, follow these rules:
- Always warm up before a main set of intensity, and always cool down after.
- Mix hard riding and recovery riding during each main set.
- Ride at the target intensity. You’ve planned a workout to have a certain training benefit. If you go harder or easier, your efforts won’t bring about the specific physiological adaptations you are trying to achieve.
- Start timing the interval when you start riding hard (assuming you’re doing structured intensity). RPE and power respond immediately to an increase in effort; however, your heart rate may lag the increase in intensity. Stop timing the interval when you stop pedaling hard; your heart rate may not fall immediately.
- Always recover fully before the next hard effort unless you are training to hammer club rides or race.
- Don’t struggle to maintain intensity. If you can’t stay in the intensity zone planned for the main set of a workout, then just cool down and go home. Riding below the target intensity will just fatigue you without the intended training benefit. If you continue below the planned intensity, then you’ll just need more recovery days before an effective training session.
- Build intensity appropriately during the main set rather than peaking early and then fading. For example, if you’re riding in the sweet spot up five hills try to pace yourself so that you’re putting in your best effort on the fourth or fifth hill rather than on the first and second.
- Plan a range of efforts, for example, three to six repeats. The number you actually do should depend on how many quality repeats you can do at the planned intensity. Stop with one more hard effort still in your legs. Always end the main set feeling like you could have done one more good effort.
- Master the starting range of efforts before increasing the overload. For example, the starting range is 3 – 5 repeats of [6 – 8 minutes hard with 3 – 4 minutes of recovery between each hard effort]. Start with 3 repeats of 6 minutes hard with 3 minutes of recovery between each. Build up to doing 5 repeats of 8 minutes hard with 4 minutes recovery between each. Only then increase the overload.
- Master the first intensity pace before stepping up to the next level of intensity. For example, you should ride comfortably for extended amounts at the threshold pace before you start training at the sweet spot pace.
- Increase overload by increasing just one of the following at a time: Increase the number of repeats; Increase duration of the hard efforts; Reduce the recovery between hard efforts; Increase the intensity of the recovery breaks between hard efforts, still staying below the intensity of the hard efforts; Step up to the next level of intensity.
- When you increase the intensity, start with shorter and / or fewer intensity efforts and build back up
- The harder the effort, the shorter the duration. Hill climbing / headwind efforts are the longest, power pace are shorter, sub-barf are still shorter, barf are even shorter, eyeballs out are very short and sprints are the shortest.
- The harder the intensity, the more days of recovery you need between sessions. You may do two days of hill climbing / headwinds workouts in a row if you can do a quality workout the second day. Allow at least one recovery day between power pace workouts and at least two days between sub-barf, barf, eyeballs out and sprint workouts.
Intensity is like prescription medicine. Too little and you won’t get better, and too much and you may get worse! The wrong medicine won’t do any good, and may also make you worse!
Coach John Hughes earned coaching certifications from USA Cycling and the National Strength and Conditioning Association. John’s cycling career includes course records in the Boston-Montreal-Boston 1200-km randonnée and the Furnace Creek 508, a Race Across AMerica (RAAM) qualifier. He has ridden solo RAAM twice and is a 5-time finisher of the 1200-km Paris-Brest-Paris. He has written over 40 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach John Hughes. Click to read John’s full bio.
The problem I have with this article is that it does address those with medical issues who are essentially ill-advised to ride hard at any time. For example, I have Atrial Fibrillation, Aortic Valve Disease, Sick Sinus Node Syndrome, and have an implanted pacemaker. I have competed quite successfully in the past in duathlons and the Senior Games. Now my electrocardiolgist does not want me to engage in intense efforts period. I still ride, but on some paved trails at a fairly relaxed pace and am able to ride 40-45 miles. I’m sure there are many others who have similar medical issues that prevent them from doing intense cardio exercise. Just thought I’d share this with you.
I assume you are using a HR monitor with appropriate zone analysis perhaps even better with power meter. I DO NOT think this is close to solution (especially wiht HR prolems and sick sinus with pace maker) but may provide a little something???
Robert Armstrong, I think a Power Meter would suit you better. Its actual effort instead of perceived effort. John March is working on a new Power Meter ebook right now… stay tuned. But, to answer your concern, of course, coaches will interview a client first and this information will then be discussed. Im sure John Hughes agrees that the first thing we would do as coaches would be to contact your MD and discuss a training plan together.
I agree, Robert Armstrong. So does my cardiologist. Only those that have had the elephant on their chest understand that a person never wants that elephant back on their chest! I know well the signs of impending problems with regard to over-exertion, and I won’t go to that limit. My friends keep telling me that unless I “push it” I’ll never get “faster.” Honestly, I look at getting faster as a faster way to be pushing up daisies! I got into riding for the fitness aspects, but never intended upon RACING. My “average speed” for a ride is at the bottom of the list. In addition to the over-exertion bringing on the angina and other warning signs, I also have severe problems with cramping 4-12 hours after I’ve “over done it.” Trust me, you don’t want both adductors cramping up on you at the same time! Nope. I’ve done that too many times already…and that can happen even without over doing the heart-rate thing.
Everyone has to learn their own limitations. Everyone has different goals. At age 70, I don’t have a goal to “average 15+ mph for a metric century”…on a bicycle or on my Catrike 700! My wife thinks I’m crazy for even doing the metric or full century rides, let alone a faster “average speed.”
The RPEs you suggest are very descriptive. 🙂
I have an article Fred wrote: “Equations for Cyclists”. He also lists RPEs in there. However, his RPEs are different to yours, especially at the low end. For example, his conversational pace is 6, whilst yours is 2-3.
I guess it doesn’t matter, as long as when you tell someone to ride at 2-3, they are using your scale, rather than Fred’s.
Your thoughts?
“If you’ve been riding for years then just piling on more miles brings very little improvement . , .”
Hello? That “piling on more miles” you refer to is otherwise known as cycling, and its purpose is not to foster improvement — improvement of what? — but rather to provide the exhilarating experience of self-propelled, silent penetration of the magical world we inhabit but so rarely see. How dare you portray my beloved sport as an ordeal to be overcome by the virtuous few?
Your whole “intensity training” article describes cycling as some kind of penance we must suffer through if we are to progress to being ever faster, ever stronger. As a 20-year-old I might have responded to this approach, but at age 70 the victory of being first past the city limit sign appeals to me NOT AT ALL.
My body lacks the strength and stamina of youth and no amount of training will ever get it back. But more importantly, I do not want it back! I don’t need it! My idea of cycling enjoyment these days is completing my 20 mile training loop at a brisk (for me) pace, and during the process enjoying the lovely sights and smells a Northern California rural road offers at this time of year.
So please stop promoting the mindset that sport cycling must be a test of will, that we are forever competing against our current unworthy selves to be faster and stronger than we so recently were. This Calvinist mindset undermines what should be a supremely pleasurable activity, one that need not be justified by the amount of suffering recorded by our power meters. Power meters are the invention of the devil! Give your readers the freedom — without guilt! — just to get on their bikes and go for a ride.
Kudos, sir. With 4 decades nigh and 2 ablations past, just ride as the Badger(.?) and Grant would say.
Score, not decades. Meh
Couple of comments on “conversational pace”
– If you are actually really having conversations then, unless you are using a power meter, it is unlikely you will be doing any useful training. Unless they have a good leader who knows what they are dong most group rides, by definition, will be at the pace of the slowest rider and most of the time will be spent in a recovery zone.
– From my experience, unless you have unlimited time, conversational pace is not an efficient way to train. To get the maximum benefit you need to ride for 4-7 hours without stops like the pros do. You can get the same adaptations in less time by moving up a notch to low “tempo”, the point where you start noticing a change up in your breathing and conversation, while not forced, is not easy.
My first visit to your site. As a LAB,
LCI, I found the articles informative.
I’m over 70 with emphysema and have had quad biomass surgery. So, my riding goals are much different. I still ride century rides albeit a slower pace
13.5 to 15.0 is my comfort zone.
Intensity is not for everyone as I stated previously. I, for one, have been told to avoid it because of my heart pathway issues which now include having a bovine aortic valve. I trust my cardiologists on this subject far more than I do i Fitness trainer or enthusiast. I ride for recreational exercise and I just love being outside. Each individual must sort this out for themselves. As I approach my 79th birthday, I know my own body better than anyone.
While not stated explicitly it’s obvious that these recommendations are for healthy cyclists.
Wow! Why the hostility?
Coach Hughes spends time trying to help those who want his help.
There are so many ways to enjoy a bicycle let’s not get hostile to each other.
I love to train and analyze the numbers and enjoy the competitive Spirit of riding bikes fast with others. Sometimes we just ride to have a conversation and look at the sights.
Those of us who suffer to get faster enjoy the suffering! Different strokes, get it?
Yes.
Some of us just ride to enjoy the ride.
And some of us ride to become stronger riders.
And the same rider can do one or the other on any given day.
As Mike said above, Why the hostility?
Well said Mike.