hobkirk

During an easy ride, is it a good idea to throw in an occasional (every 30 minutes?) HARD burst (MAX effort)?

I am currently riding 4x8 intervals once a week, but I cruise on most of my other rides.

THANKS!

Carbonfiberboy 

Depends on what you're doing. Right now we're tapering for an event, and that's exactly what we're doing as part of that taper. We go 1' on, 5' moderate, 2-4 repeats.

elcruxio

No.

Or depends what you're looking for. If bonking is it, then go for it.

However the reason why I like to keep HIIT and low intensity mostly separate is because how carb greedy the body gets at times.
Basically on a slow ride you're trying to train your body to burn fat so you'll get more power out with the same ratio of fat burn which translates to much longer higher intensity efforts. Iron Man pro's are really good at fat burning and can crank up some serious power with a high fat burn percentage.

When you then increase the effort levels you lower your fat burn and raise your carb burn since carbs are a much more powerful energy source than fat. Problem is, that you only have a very Limited amount carbs stored so you either have to eat constantly or keep the trip so short you don't run out. Running out of carbs is not a nice feeling.

At this stage getting both the fat burn efficiency training and the higher intensity cardio those bursts would give sounds like a really good idea right? But the problem is that the human body is not a hybrid engine that smoothly switches over from one fuel to the next. Or rather, it switches from fat to carbs really smoothly, but going back is the problem. Once you go full carb burn it can be quite difficult to go back to even moderate fat burn without stopping and having a breather.

So as a summary, when your body gets the taste of the carbs, it doesn't want to go back to fat if you don't radically drop your riding intensity for a while or stop altogether.
It's of course not QUITE as radical as that so a hill will not destroy your long ride even if your HR goes up a bit. But doing high intensity intervals probably will turn into very high carb burn and on a long ride you'll then run out.

Of course HIIT training also gives some benefits in fat metabolism and it could be almost as effective in training fat burn as long steady rides. There was also a study which showed that a HIIT session before a longer ride gave the maximum benefits in fat metabolism training. But If I remember correctly they had a decent sized break in between (hour or so)

So my suggestion is to of course do both, but don't mix them together. you'll gain no obvious benefit and you'll make your longer rides harder for no reason.

gregf83 

Nonsense. A normally fueled body has plenty of glycogen for a long workout with or without HIIT.

hobkirk: What are your objectives? I have a set of steep hills (about 50m elevation) that I sometimes use for hill repeats. I'll do 6 to 8 reps of a hill that takes 60-80 Secs to climb. I go easy about 5 min in between climbs. With a 20 min warmup and 10 min warmdown I can get the workout done in an hour but I'm pretty wiped at the end and my arms are usually more tired than anything as I do at least half the reps standing. I'm doing these climbs hard but not all-out. I might do one or two all-out but not sure I could do all of them all-out.

As it is this is the most intense workout I have but it's very time efficient. I think it's mostly useful for building anaerobic work capacity which is great for racing. I wouldn't normally do these year round and would plan an easier ride the day after.

OldTryGuy

It's always good to upset the norm. Never know when you're going to have to out ride an ankle biter or something bigger.

RR3

Are you aware of any research or other data supporting your opinion?

Consumption of a large amount of carbohydrates generally will impair fat burning but I have never heard that oxidation of glycogen would inhibit the resumption of fat burning rather quickly when you dial back the power. I don't know but would appreciate any direction to research supporting what you wrote because it does not square with my experience.

hobkirk

I have all the typical goals: go faster, farther, and do it more easily. Unfortunately my lifelong eating compulsion makes me fat (228# at 6'1") and it seems everyone gets slower as they age (69). I started riding after one knee was replaced on May 10, I've ridden over 1K miles since then, I've lost just over 10#, and I've been experimenting with polarized training for 6 weeks. It seems to be helping, and the intervals (4x8 on a flat [average ascent of 26'/mile] course) has not hurt as much as I expected. Two years ago I did intervals on a steep hill, 5 or 6x8.

I am now riding stronger than last year (recovery from a hip replacement) and I don't notice hills nearly as much as I used to, so I am VERY pleased. But I'm always willing to learn more. The "bursts" question was to find if that would make the Zone 1 rides more productive. "No" confirms my suspicion.

Thanks