Training & Nutrition - HR for building endurance

Most of the recommendations for building endurance seem to be that you ride long periods of time in the 65-75% max HR. My question is if its better to be nearer the 65% or the 75%, or does it not make any difference? My guess is that its better to be at 75-80%, but I am not sure. It sure is a lot easier to be at 65%.

Doesn't make that much of a difference really between 65 or 75%. Endurance is about saving your muscles by spinning easy gears and eating enough food in a timely manner to maintain your energy stores. If you've got plenty of time, then sure, use 65%. If you've got plenty of food, go for 75-80%.

I spend most of my time at around 80-85% of my lactate threshold HR, which is somewhere around 70% of my max heart rate.

There is a time to spend time at or about the LT, but it's really easy to overdo it. Don't feel bad if you're around 65%.

From all I have read, there are no beneficial adaptations that happen faster at 65% than 75%. 65% is considered the very bottom end, below which there are no aerobic adaptations at all. All the beneficial adaptation rates increase with increasing aerobic effort, (except for muscle michondria, which peaks in zone 3 or "tempo").

To increase endurance, work out aerobically. To improve more quickly, work out at the high end of your aerobic range.

I don't understand the coaching recommendation to log endless hours of endurance level effort. There doesn't seem to be any basis for it.

There probably is an optimal intensity for increasing your aerobic threshold. The aerobic threshold is the highest intensity you can exercise while primarily using fat for energy. Any intensity of exercise will usually increase the aerobic threshold.

However, exercise theory holds that maintaining an exercise intensity that requires all the slow-twitch oxidative fibers to be recruited without invoking the faster twitch fibers and glycogen reserves will be the most effective. Going too hard develops fast twitch, glycogen-using fibers.

Everyone's aerobic threshold varies with genetics and training. Muscle fatigue will affect the heart rate at threshold.

My own experience suggests that progressive pace workouts are a good drill to raise the threshold.
In other words, a steady rate workout, starting at 65% of MHR and increasing to 70-75% across an hour or more. (the longer the better)

what do you guys recommend for people who live in places with a lot of intersections\stops, etc. i.e. "junk miles".

would you try to shoot for an average of 65-75%, even if it means going harder in some places? or would you keep the intensity down and add additional riding time?

sometimes it takes me 45 minutes to ride to a place where i can keep a steady effort. i'd like to get some benefit out of all those junk miles if i can.

what do you guys recommend for people who live in places with a lot of intersections\stops, etc. i.e. "junk miles".

Well, once you've had a warmup, you can use stops as interval markers. Sprint from one stop to the next, spin to the following stop, repeat. As long as you have at least 30 seconds or so between stops, you can get in some good intervals.

73% of MHR or all your riding is useless and you might as well be at home eating potato chips.

Yeaup, thats how it works. It's exactly the same for everyone and everyone should do all endurance workouts at that number.

Humm, in that case I prefer to stay home and eat chips and pizzza!

I don't understand the coaching recommendation to log endless hours of endurance level effort. There doesn't seem to be any basis for it.

My guess is that in order to sustain a high level of performance over a few months you have to put in the volume early. It helps you recover.

I've also heard that it helps build those capillaries.

I've also heard that (long endurance rides) helps build those capillaries.

That was the common wisdom for a long time, but it was discredited a few years ago. Capillary growth doesn't happen much without high intensity training, according to studies.

what do you guys recommend for people who live in places with a lot of intersections\stops, etc. i.e. "junk miles". Junk miles only exist in the sense they require energy and time spent exercising that serves no purpose to promote training adaptations.

If your "city miles" are the only miles you can ride, then they are not junk. Since, I live in an urban area, I often ride laps in a nearby park so I can maintain some level of constant intensity.

In other cases, I often ride city blocks using all right-turns, of course I often run stop signs and piss-off drivers when ever I get the chance.....

If I were you I won't do my intervals through the streets of NYC. Head to either Prospect Park or Central Park and do loops. Time yourself. In CP If you can complete a lap under 18 minutes, you are getting a good workout provided that you do more than 4 laps there. Under 18 minutes is about 20 to 21 mph average speed. Under 17 minutes is about 23mph or so. For Prospect Park, under 9 minutes per lap is good. For the same reason you mentioned, I would rather do loops in either park than to spending over an hour heading to NJ. I don't feel I am getting easy miles riding in the park since power is power. As long as I can maintain my power output, my legs won't know if I am riding in NJ or in the parks. My favorite thing about training in the park is that I can really waste myself during the session not worrying about the trip riding back home. I just hop on the subway.


what do you guys recommend for people who live in places with a lot of intersections\stops, etc. i.e. "junk miles".

would you try to shoot for an average of 65-75%, even if it means going harder in some places? or would you keep the intensity down and add additional riding time?

sometimes it takes me 45 minutes to ride to a place where i can keep a steady effort. i'd like to get some benefit out of all those junk miles if i can.

When you are riding at a lower percent of your HR your burning more fat. Since fat requires more oxygen then carbs do for oxidation fat is more commonly used at lower intenitys and carbs for high intensity. you can only store about 1600 calories of glycogen (glucose in the muscle) in your body, enough for roughly 2 hours but you have enough fat to run for new york to miami. If you work at burning fat(at lower intensitys) you will be able to increase you oxygen consumption at sub max and burn more fat giving you more endurance. and you build capalarys (if you ride fast during your base training you will burst them)

If you work at burning fat(at lower intensitys) you will be able to increase you oxygen consumption at sub max and burn more fat giving you more endurance. and you build capalarys (if you ride fast during your base training you will burst them)

1. Capillary growth doesn't happen at endurance pace (or happens very slowly);
2. capillaries don't burst under high intensity, they grow fastest at high intensity.
3. endurance comes from stressing the aerobic system, which happens most quickly at high intensity.

When you are riding at a lower percent of your HR your burning more fat. Since fat requires more oxygen then carbs do for oxidation fat is more commonly used at lower intenitys and carbs for high intensity. Uh no, for the same number of calories metabolised to ATP, lipids don't require any different amount of oxygen than carbs. Oxygen-consumption is directly related to power-output and if you're cruising along at 75-watts, yeah you'll burn 50% fat for about 120-fat calories/hr. However, if you ride at 150-watts, you'll burn 25% for 150-fat calories/hr and use up about twice as much oxygen. The trick is to plug in the actual numbers. Higher intensities burn more fat, even though that's a lower-percentage of total calories burnt. And higher intensities will also consume more oxygen.

Want to build endurance? Burn off as many calories as quickly as possible for as long as possible. Do a 3-hour ride at the fastest pace you can hold for 3-hours straight at a steady pace with no stops. You'll need to start eating 1.5-hrs into the ride or else you're gonna bonk at 2.0-2.5hrs. It's the 3rd hour at this pace that really builds endurance.

Oh yeah, I always carry a can of coke or Red Bull when I am out doing my 2 hours high tempo ride. Anything over that I make sure I eat something after the 1 hour mark. Either 2 power gels or energy bars. Still, after 2 hours my back will get sored because I would be spending a lot of time in the drops or on the hoods in a TT position.


Uh no, for the same number of calories metabolised to ATP, lipids don't require any different amount of oxygen than carbs. Oxygen-consumption is directly related to power-output and if you're cruising along at 75-watts, yeah you'll burn 50% fat for about 120-fat calories/hr. However, if you ride at 150-watts, you'll burn 25% for 150-fat calories/hr and use up about twice as much oxygen. The trick is to plug in the actual numbers. Higher intensities burn more fat, even though that's a lower-percentage of total calories burnt. And higher intensities will also consume more oxygen.

Want to build endurance? Burn off as many calories as quickly as possible for as long as possible. Do a 3-hour ride at the fastest pace you can hold for 3-hours straight at a steady pace with no stops. You'll need to start eating 1.5-hrs into the ride or else you're gonna bonk at 2.0-2.5hrs. It's the 3rd hour at this pace that really builds endurance.

My understanding agrees with the first few posts... the subsequent discussion is getting confusing. Perhaps the OP isn't interested in endurance as a foundation for faster riding, but I am.;)

My understanding (in unscientific terms) is that you put in your 1K miles near your aerobic threshold to recover/develop all the components required to maximize use of oxygen and fat as a fuel source, generally looking to increase your average speed by 1 or 2 mph while staying aerobic.



Want to build endurance? Burn off as many calories as quickly as possible for as long as possible. Do a 3-hour ride at the fastest pace you can hold for 3-hours straight at a steady pace with no stops. You'll need to start eating 1.5-hrs into the ride or else you're gonna bonk at 2.0-2.5hrs. It's the 3rd hour at this pace that really builds endurance.


So, are you saying the real reason we're staying aerobic so that we can maintain the training pace into the third hour, thus enduring to the point we've truly depleted the carb stores, and forcing our bodies to run off more fat?

I really don't understand how heart rate ranges can be divided so neatly into zones that will predict exactly what your body is doing. When someone asks how to lose weight, the dogmatic response is "burn more calories than you consume." So when you're in a high training zone, shouldn't whether or not you lose weight depend on how many calories you're burning and not your heart rate? Obviously, there's the question of whether or not you are losing muscle or fat, but I thought that muscles only wither way from lack of use or from not consuming enough protein...

So when you're in a high training zone, shouldn't whether or not you lose weight depend on how many calories you're burning and not your heart rate?

Yes, but you are forgetting that your HR is an indicator for how hard your body is working. In proportion to your individual strength and endurance HR is the best measuring stick for a work out, given the relative nature of endurance and strenght. So, zones (determined by your MHR and/or VO2 max) make complete sense for any individual training program.

Hate to say this but your HR only shows how hard your heart is working, not your body--in this case your legs. The best measuring stick is a power meter. It measures how hard your leg muscle is working. Due to cost and the steeper learning curve of training with a power meter, HRM is probably the more better choice.


Yes, but you are forgetting that your HR is an indicator for how hard your body is working. In proportion to your individual strength and endurance HR is the best measuring stick for a work out, given the relative nature of endurance and strenght. So, zones (determined by your MHR and/or VO2 max) make complete sense for any individual training program.

So, are you saying the real reason we're staying aerobic so that we can maintain the training pace into the third hour, thus enduring to the point we've truly depleted the carb stores, and forcing our bodies to run off more fat?Yes, something along those lines. I think "endurance" is composed of multiple factors. Muscle-fatigue is typically what limits most people, they get sore and cramped up and quit well before they run out of glycogen or energy. By riding at an aerobic pace using low gears and spinning, you can ward off muscle-fatigue for as long as possible. If you do a ride with anaerobic intervals and king-of-the-mountain sprints, it's going to be hard to keep up that kind of pace for more than 2-hours, much less 3.

So another aspect of endurance is self-control in pacing. Being able to ride right at your target average-speed without too much of a deviation above or below it (adjusted for terrain) will let you cover that distance at the fastest pace possible and burn off as many calories as possible (to tax your energy-delivery system).

Finally, if you've mastered gearing & spinning along with the LSD aerobic pacing, then what limits your endurance is energy-delivery. Due to the limited rate of digestion of even the highest-GI carbs (pure glucose), you're still limited to absorbing only 200-250 cal/hr. At an average pace of 20mph, you're burning through 700-900 cal/hr so there's no way you can eat and digest as fast as you're burning, so your blood-glucose and glycogen supply will steadily decrease as you ride regardless of how much you eat. That's where "endurance" training in metabolizing fat effectively comes it. This is an interesting article: AJCN - Lipid metabolism during endurance exercise - Horowitz & Klein (http://www.ajcn.org/cgi/content/full/72/2/558S?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT). You'll notice that as exercise time increases, fat-utilization increases. Note the 1st 30-minutes has little fat-burning while 60-minutes would burn off about 3x as much fat (get total by integrating area underneath curve):



By the 3rd to 4th hour, your lipolysis-rate increases tremendously (adipose storage-tissue converted to fatty-acids and dumped into bloodstream for energy) over the 1st two hours. In fact, during that 1st hour, you're just warming up. The increased fatty-acid utilitization is caused by lowered blood-glucose, increased glucagon & cortisol. So to get to the near-depleted state as fast as possible, you want to ride at a high aerobic rate for the 1st two hours; you also get the aerobic benefits of doing some tempo workouts. Or you can ride at a slower-rate for 3-hours, it's up to you and how much time you have. Then that next final hour before the bonk is when you really tax your energy-delivery system to improve endurance.

But there are negative side-effects, so you don't want to get too depleted and definitely not bonked. The low glucose, high glucagon/cortisol state is very detrimental to to fitness as it increases the muscle-catabolism rate. So you want to eat sufficient amounts to keep blood-glucose elevated enough to not tear apart your muscles too much and undo any fitness gains you may have. This is why ultra-marathoners and high-mileage riders tend to be gaunt and lean, they've consumed quite a bit of muscle in the process of training for endurance.

Muscle-catabolism during the recovery phase afterwards also has more to do with ingesting sufficient carb-calories in the recovery drink than protein. Without the blood-glucose in the bloodstream to suck in and convert to glycogen, the muscles themselves are disassembled and converted to glucose to restore the glycogen supply. Ingested protein doesn't have as strong of an effect in warding this off as glucose.

Some articles on endurance-improving compounds:

AJCN - Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice (http://ajpregu.physiology.org/cgi/content/full/288/3/R708)
JAP - Effect of a divided caffeine dose on endurance cycling (http://jap.physiology.org/cgi/content/full/94/4/1557?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT)
JAP - Metabolic and exercise endurance effects of coffee and caffeine ingestion (http://jap.physiology.org/cgi/content/full/85/3/883)

Hate to say this but your HR only shows how hard your heart is working, not your body--in this case your legs. The best measuring stick is a power meter. It measures how hard your leg muscle is working. Due to cost and the steeper learning curve of training with a power meter, HRM is probably the more better choice.

Right. But how hard your heart works is an indicator how hard your body is working (without considering everthing else). I am not saying it is the absolute indicator (although I was not at all clear about that above:rolleyes: ) A power meter is ideal and far more accurate, but the question had to do with the value of heart rate zones, and while HR can not tell you "exactly" what your body is doing, it provides a pretty darn good ballpark to set an effective (noncompetative) workout program for those of us that don't ride Dura Ace components. :)

Yes, something along those lines. ..... AJCN - Lipid metabolism during endurance exercise - Horowitz & Klein.
Thanks, Danno! Excellent article!