Speedwork: something isn't working

"Charlie Pendejo" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Tony said:

Isn't 8 weeks a wee too long for speedwork though?

Is that a trick question?

Nope, just a less uniformed one 😉

Quoted message said:

Answer: it depends, heavily.

Specifically, on whom you ask, in the context of what overall program,
and what you're calling "speedwork".

Though tfactor clearly ran harder than tempo effort, his stated intent
was T(empo) pace. One could run tempo stuff the whole year round.
(And strides. I suspect just doing tempos and stridey/reppy/hilly/
fartleky short fast bits year round would keep many of us around 96%
of our ultimate peak condition...)

You're probably right, but it would quickly wear me out.

Quoted message said:

Donovan, last I recall him speaking at length of his training, was
doing the same tough weekly track session ad infinitum with continual
improvement. In Noakes you'll see some legends employed little or no
periodization. Frank Shorter comes to mind as one who ran essentially
the same week all the time.

Yea I remember that too, but I also remember him attributing his best race
times with high mileage in addition to those 5k DeCastella workouts.

Quoted message said:

Daniels' programs, at least in the first edition of _DRF_, consist of
four phases each lasting six weeks. First phase is base; next three
incorporate a mix of workouts with the primary focus typically
shifting from faster reps to VO2max intervals to tempo runs. And in
the text (Daniels actually does relate a number of ideas, once you get
beyond the rows and columns of digits) he implies the timing isn't set
in stone but more of an optimal compromise: 6 weeks = you squeeze 90%
of the juice from each workout type / physiological subsystem; shorter
= less juice, longer = diminishing returns. I can claim direct
experience with Daniels (1).

Lydiard has you running base (aka conditioning or marathon
conditioning) "as long as possible" before shorter race prep/peaking
phases: hills, anaerobic, sharpening. From reading, it seems the
timing is more critical in this peaking program and trying to extend
one of these phases much beyond 4 weeks or whatever would throw you
off considerably.

I think this approach makes the most sense for me personally.

Quoted message said:

(1) Having followed his 10k training pretty faithfully last spring, I
think *for me* *at my stage of development* those eighteen weeks did
indeed seem "a wee too long". I saw a big jump around the end of
phase 2 (first phase of workouts, emphasizing short reps) - sub-65 at
Philthy ten miler - and then little to no race-proven improvements
from the last two, three months of the program. Though all those
workouts may have set me up well for the marathon training which
followed.

I don't see myself going back for another season of Daniels, but also
kinda suspect that I'd have seen more benefit further into the season
had I gone in with a stronger base and/or twenty years younger.

Interesting, thanks Charlie. We have examples in rec.running, like Mark H.,
of those who go hard all year. We've also got those who follow programs
pretty closely, like Phil M. When I was in my late teens early 20s, I
trained by feel: run pretty much every day, go hard when I felt good, go
easy when I was tired. But I know I wasted some effort in training by going
too hard, but when you're young, you bounce back quicker.

(And now, a side trip into memory lane...)
Now I never go all out in training. Back in the day, I would do it because
it was fun. I was just thinking about this last week when I ran a section of
old trail that I used to run back in the 80s. I still don't know how I
managed that 3+ mile 1100' climb very rough hiking trail section in 26 min
back then, when it took me 43 mins last week as part of my long run, and
when about 33 minutes was my best very hard effort when in pretty decent
shape 8 years ago. The answer is I was both young and also a different
runner with much more power (and abandon) back then. Even 5 years or so
after my PR on that trail I was an entirely different runner and, though
lighter and fitter in most ways, I could only manage 31 mins there. By that
time all the soccer conditioning and vast sprinting reserves I'd developed
in my youth were pretty much gone.

-Tony

Tony said:

I still don't know how I managed that 3+ mile 1100' climb very rough
hiking trail section in 26 min back then, when it took me 43 mins
last week as part of my long run, and when about 33 minutes was
my best very hard effort when in pretty decent shape 8 years ago.

Heh, aging's a [censored], no?

Gary - dude, if you're listening, DON'T GROW UP! Save your running,
stay young forever.

Ah well, I guess if you're gonna get old anyway, might as well keep
running. Whatever anyone thinks of elite masters women with
ridiculously low body fat, in general older runners look and seem to
feel a hell of a lot better than their couch potato counterparts.

In article <[email hidden]>, [email hidden]
says...

Quoted message said:

samson said:

So to recruit more anaerobic pathways, what is the better length to
run intervals, a 200m or 400m?

I'd start by cautioning that you probably don't want to specifically target the
anaerobic system if your goal is distances of 800m and up.

Thanks, Elflord. I run 8 10-minute miles a day more or less and
I'd like to get my times slowly down. My goal is to have my daily
summer run at round 8 8-minute miles to get ready for a marathon and
5K in the fall. Of course just doing this daily run is making my
conversational miles easier. I guess I'd like to kick start my
anaerobic system a little bit. Should I run 200m, 400m, or both?

S.

Quoted message said:

Thanks, Elflord. I run 8 10-minute miles a day more or less and
I'd like to get my times slowly down. My goal is to have my daily
summer run at round 8 8-minute miles to get ready for a marathon and
5K in the fall. Of course just doing this daily run is making my
conversational miles easier. I guess I'd like to kick start my
anaerobic system a little bit. Should I run 200m, 400m, or both?

You could do both, but it's probably more important to mix up full-
recovery intervals with partial-recovery intervals. (Standard
thinking associates the first more with strength training or technique
training and the second more with LT training). Similarly to weight
training, you need to pick an intensity level and stick to it for the
prescribed length of time / distance, or until your form starts to
deteriorate. If you take full recoveries, then the expected result
will be that you'll be fresh and able to recruit all the necessary
muscle fibres in the next bout. Don't do maximal effort in all the
sets, or you'll be sore for the next few days. In this case you
should have similar times from one repeat to the next. If you take
only partial recoveries, then obviously you cannot max out in the
beginning. Take it easy. After a few repeats, muscular fatigue will
set in, regardless. Use the first couple of workouts to figure out
what is the appropriate level for you.

"Elflord" <[email hidden]> wrote

Quoted message said:

Quoted message said:

pennance. Going too hard impares your growth, and in fact trains the
anerobic systems to the detriment of the aerobic systems, a bad thing for
distance runners.

Quoted message said:

Dan, this isn't true.

Quoted message said:

Whether or not what you're doing "trains the anerobic(sic) systems" is not
really about how much it hurts, it is about training intensity.

Hmm, so we differ in that I think (as a general rule) that the more it
hurts, the harder you're training, wheras I assume you think that there is
no or only a weak relationship there? If you've got a way to do more
intense training without increased pain, please inform us! (I'm speaking
here about intervals, repeats -- short high intensity stuff. You can wipe
yourself out by doing too many miles at a sub-painful level, but that is
another topic)

Quoted message said:

Also, the relative contribution of the anaerobic system is not the same as
accumulated blood lactate. The latter may "feel" anaerobic, but it doesn't
directly relate to the relative contribution of the anaerobic pathway.

My authorities are Marty Liquori (3rd ranked in world at 5k), and Ingred
Kristiansen (wr holder from 1500 thru marathon, the latter record for many
years). Ingrid's hubby and coach is a Ph D exercise physiologist, and they
explain their training philosophy in some detail on her website in the
physiology section. I found the things they emphasized enlightening
(successful application of knowledge starts with filtering out the chaff and
selecting the wheat).

In addition, I made a big breakthrough in my own training when I reduced the
intensity of my intervals from gut-wrenching and painful to quick and
smooth.

So you can talk blood lactate and non-correlation of intensity to pain all
you want, but I maintain based on the evidence above that there is an
optimal pace to do speedwork at for dx running, and you can zero in on that
pace by feel, and that pace is not painful, just hard. (Is that sentence
worthy of CP?)

You mentiond that you do your speed very hard, do I remember it correctly?
And yet, your mile is 80% wava, and all your distance work is less. Could
be genetic, or could be (my theory) that you're not training optimally for
dx. Btw, according to a reliable witness, I ran a 4:40 mile (80% wava) in a
workout when I was in 80+ wava shape at all distances from 5k thru marathon.

Quoted message said:

You can run your legs off in 2-mile repeats until you wish you were dead,
but
you will recruit anaerobic pathways much more heavily with a few
controlled
200m reps, with full recoveries, and the 200m reps will hurt considerably
less.

That makes sense, but there is still the notion of the optimal pace to run a
repeat at for improved goal-race performance. That is the issue I'm zeroing
in on.

Quoted message said:

You would not *feel* like the anaerobic pathways are being recruited,
because
it isn't possible to accumulate much blood lactate in 30 or so seconds.

Oh, I would disagree -- I used to try and keep up with a speedy friend who
was running 20x220 @32" when I was capable of 35's, and trust me, plenty of
lactate accumulates when you do them over your head, and it is quite
painful, too. I still remember those workouts, what, 25 years later...

Anyway, not trying to get into a big D contest, just trying to zero in on
the optimal intensity for the goal in mind. And to return to my original
point to tFactor (who isn't buying what I'm saying, judging by his silence),
he ran that workout too hard.

-- Dan

--
Posted via a free Usenet account from http://www.teranews.com

Dan said:

So you can talk blood lactate and non-correlation of intensity to pain
all you want, but I maintain based on the evidence above that there
is an optimal pace to do speedwork at for dx running, and you can
zero in on that pace by feel, and that pace is not painful, just hard.
(Is that sentence worthy of CP?)

B.

Some of mine, even *I* can't grok in the rereading. Yours is too
coherent for an A, a little too brief for even a B+. But a solid B:
no cause for shame, particularly if written stone cold sober.

I haven't been following close enough to guess whether this might be
what Donovan means, but where I see intensity diverging from pain is
when you factor in the durations of the work and recovery intervals.
The intensity at which we can ("optimally"😉 run 200m with 5' recovery
is very different from 800m, 90" recovery or even 200m, 30".

samson said:

In article <[email hidden]>, [email hidden]
says...

Quoted message said:

samson said:

So to recruit more anaerobic pathways, what is the better length to
run intervals, a 200m or 400m?

I'd start by cautioning that you probably don't want to specifically target the
anaerobic system if your goal is distances of 800m and up.

Thanks, Elflord. I run 8 10-minute miles a day more or less and
I'd like to get my times slowly down. My goal is to have my daily
summer run at round 8 8-minute miles to get ready for a marathon and
5K in the fall. Of course just doing this daily run is making my
conversational miles easier. I guess I'd like to kick start my
anaerobic system a little bit. Should I run 200m, 400m, or both?

You could do either, but the goal is to improve running economy -- how
far you can run per calorie. Specifically working the anaerobic system
isn't really a factor.

If you have sufficient base, what Daniels calls "R" workouts, or hill reps,
with full recoveries are useful. e.g. 6x400m or 6x some hill that takes
90-120 seconds to run up. But do these without a good base and you can
get injured quickly.

An easier way to approach the same goal is to incorporate strides into
your workouts.

Cheers,
--
Elflord

D Stumpus said:

"Elflord" <[email hidden]> wrote

Quoted message said:

Quoted message said:

pennance. Going too hard impares your growth, and in fact trains the
anerobic systems to the detriment of the aerobic systems, a bad thing for
distance runners.

Quoted message said:

Dan, this isn't true.

Quoted message said:

Whether or not what you're doing "trains the anerobic(sic) systems" is not
really about how much it hurts, it is about training intensity.

Hmm, so we differ in that I think (as a general rule) that the more it
hurts, the harder you're training,

Yes, that's a tautology. It's harder to do something that hurts more.

BUT it's not true that training harder is always more anaerobic. VO2 max
intervals are predominantly aerobic, yet they are extremely demanding.

Quoted message said:

wheras I assume you think that there is
no or only a weak relationship there? If you've got a way to do more
intense training

"Intense" means a lot of things, I meant in the sense of power output as
a percentage of VO2 max. In this sense, "intensity" doesn't necessarily
mean physical pain.

Quoted message said:

Quoted message said:

Also, the relative contribution of the anaerobic system is not the same as
accumulated blood lactate. The latter may "feel" anaerobic, but it doesn't
directly relate to the relative contribution of the anaerobic pathway.

My authorities are Marty Liquori (3rd ranked in world at 5k), and Ingred
Kristiansen

It's true that these people are experts, but I don't believe it's true that
they specifically say that more pain implies more anaerobic. I hope they
don't say this, because it's simply not correct.

I will note that their training philosophy works for them, and many others,
but there are other great runners who applied different approaches quite
succesfully.

I would argue that for some, going "balls out" in workouts is pretty effective,
even for distance guys. It worked OK for Frank Shorter, for example.

However, I also agree with you that tFactor may have done better with a
slightly less ambitious pace in that workout. The description of the effort
level seems incongruous with the stated goal of that workout.

[snip]

Quoted message said:

You mentiond that you do your speed very hard, do I remember it correctly?
And yet, your mile is 80% wava, and all your distance work is less. Could
be genetic, or could be (my theory) that you're not training optimally for
dx.

This is not really a matter of conjecture, as there are several other runners
who do all the same group outs as me, and a very broad spectrum of aerobic
profiles.

Trying harder in a workout doesn't make it more mile specific. To train
specifically for the mile, the first thing I needed to do was to train much
faster. It wasn't necessary to try to make it hurt more.

Quoted message said:

That makes sense, but there is still the notion of the optimal pace to run a
repeat at for improved goal-race performance. That is the issue I'm zeroing
in on.

Sure, I agree on that issue.

Quoted message said:

Quoted message said:

You would not *feel* like the anaerobic pathways are being recruited,
because it isn't possible to accumulate much blood lactate in 30 or so
seconds.

Oh, I would disagree -- I used to try and keep up with a speedy friend who
was running 20x220 @32" when I was capable of 35's, and trust me, plenty of
lactate accumulates

I would agree that it's possible to accumulate a lot of blood lactate if you do
a high number of short fast reps, but that's orthogonal to what I was getting at.

The point is that if you do those short fast reps at well within what you're
capable of, they are very anaerobic, and yet they don't result in much lactate
accumulation.

Cheers,
--
Elflord

[quote="Charlie Pendejo"]

tfactor said:

Here's the problem: I really struggled to finish the 800s in the
alloted time. I ran the first fast by about 10 seconds but it took
almost everything I had to make it under the wire for the next five. I
wasn't dry-heaving but wasn't that far from it.

Quoted message said:

Quoted message said:

The physiological benefits to these workouts better be astounding
because so far they're really setting me back psychologically.

Guess you'll find out over the next few months! You're not expecting
"astounding" results to kick in before your race in three weeks, are
you?

Quoted message said:

And on the faster side, it seems (from race results primarily, but
also how I feel) I've gotten a lot more obvious benefit from shorter
faster work - Daniels' "R" stuff, strides and reps - than VO2max "I"
workouts. And hills: hills are great, and I'd be a better runner with
better hills nearby.

D Stumpus said:

Anyway, not trying to get into a big D contest, just trying to zero in on
the optimal intensity for the goal in mind. And to return to my original
point to tFactor (who isn't buying what I'm saying, judging by his silence),
he ran that workout too hard.

I've only been silent because I was away from the computer for the
weekend. The workout seemed more difficult to me than what I thought
it was supposed to be. But I have almost no experience with this stuff
so I'm taking your point seriously. My plan is to try another session
next week at the same target pace and see how I feel.

D Stumpus said:

I think doing a 26x800 workout is unbelievably gimmicky, but whatever floats
your boat. When I was running 1:15's, and my faster friends 1:11, nobody
did workouts like that.

Short and fast, or longish and medium, or very long and easy. That is the
training formula for me for key runs. Look at how the best in the world
train. 26 x 800, sheesh!

I wasn't clear. By "26x800" I meant my upcoming half-marathon, not a
track workout! I was just comparing my pace for a few 800m runs, with
a nice recovery in between, to what pace I was hoping for when
stringing ~26 800m "runs" in a row, without any recovery.

tfactor said:

D Stumpus said:

Anyway, not trying to get into a big D contest, just trying to zero in on
the optimal intensity for the goal in mind. And to return to my original
point to tFactor (who isn't buying what I'm saying, judging by his silence),
he ran that workout too hard.

I've only been silent because I was away from the computer for the
weekend. The workout seemed more difficult to me than what I thought
it was supposed to be. But I have almost no experience with this stuff
so I'm taking your point seriously. My plan is to try another session
next week at the same target pace and see how I feel.

If you really are going for a 'T' effort workout, you probably should at least
make it a little slower than your 5 mile pace. It wouldn't hurt to slow it
down a tiny bit, especially for the first few reps.

Cheers,
--
Elflord

tfactor said:

Pendejo said:

And on the faster side, it seems (from race results primarily, but
also how I feel) I've gotten a lot more obvious benefit from shorter
faster work - Daniels' "R" stuff, strides and reps - than VO2max "I"
workouts.

It'd be difficult for me to run any faster without switching to a
sprint gait, and I'm afraid of injury if I do that. For now I'm going
to stick to speeds I can run in my regular distance gait

Yeah, by all means do whatever your mind and body agree is doable and
helpful!

But just to clarify/expand a wee bit: I was surprised to read both
your and Tony's reaction that my "tempo runs + short sharp stuff" =
injury/burnout. Maybe you guys have a different set of physical
issues from mine (I'm certainly susceptible to injury and burnout - it
sure ain't a matter of your frailty vs. my robustitude!) but I rather
thought I was describing a *low* risk scheme.

Specifically, I'm using "tempo" more liberally than the Daniels/Pfitz/
McMillen camp, spanning a range from roughly "hour race pace" to
around marathon pace. The slower the pace across this spectrum, the
further you need to go to attain similar benefits. And I expect
(well, I've gotta confess to being certain, from the reported
experiences of other runners) mine isn't the only body which seems to
get similar if not greater benefits, with less strain of the injury-
risk type, running longer slower tempos.

And in speaking of "faster than 3k/5k pace stuff" - "R" pace or
whatever - I'm talking about say 15-45 second bursts with full
recoveries. Yes, it's a different stride. Yes, you don't want to run
the first ones of a season or a session at top speed but rather build
up within the session/season. At the same time, IME these are *way*
less stressful overall than the session you described in the first
post of this thread. Seriously, this stuff is not only low risk:high
reward, it's the sort of thing some coaches (Daniels and Joe Rubio
come to mind right off the bat) agree helps *prevent* injuries from
more stressful running like intervals and races.

What this really adds up to is pretty close to Lydiard base ("marathon
conditioning"😉 training. He talks of a "high end aerobic pace" on
normal daily runs, not just super easy jogging day after day. Some of
those runs get into the range I'm calling "tempo", best I can tell
from his interpreters and disciples. And the short fast alactic
(short enough that a single 100-200m or whatever doesn't build much
lactic acid; full recoveries so that you're still not lactating much
on the last one) bits: Lydiard and many others seem to agree, work on
basic speed (, form, efficiency...) with this kind of low-stress stuff
most/all the year round.

Anyhow, this is pretty tangential to the theme of your thread. It's
only here because of course it's easier to continue a discussion via
"reply" than starting a new thread every time the topic shifts
direction a bit - I don't mean to suggest you ought to be doing X, Y,
and Z instead of A, B, and C right now.

"tfactor" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

D Stumpus said:

I think doing a 26x800 workout is unbelievably gimmicky, but whatever
floats your boat. When I was running 1:15's, and my faster friends 1:11,
nobody did workouts like that.

Short and fast, or longish and medium, or very long and easy. That is
the training formula for me for key runs. Look at how the best in the
world train. 26 x 800, sheesh!

I wasn't clear. By "26x800" I meant my upcoming half-marathon, not a track
workout!

I should have considered that angle, but at least it gave me something to
complain about!

-- Dan

Consider The Importance of (not) being (too) earnest.

--
Posted via a free Usenet account from http://www.teranews.com

Charlie Pendejo said:

And in speaking of "faster than 3k/5k pace stuff" - "R" pace or
whatever - I'm talking about say 15-45 second bursts with full
recoveries. Yes, it's a different stride. Yes, you don't want to run
the first ones of a season or a session at top speed but rather build
up within the session/season. At the same time, IME these are *way*
less stressful overall than the session you described in the first
post of this thread. Seriously, this stuff is not only low risk:high
reward,

Strides have both low risk of burnout and injury because the volume is
very low.

But once you start transitioning from strides into a full length 'R' workout
you greatly increase the risk of soft tissue injury, though you probably won't
burn out like this. People with recurring plantar or achilles tendon injuries
(especially those who are very fast in the mile/800 and arguably don't really
need 'R' work anyway) do better when they stay away from 'R' type workouts

Cheers,
--
Elflord

Donovan said:

Strides have both low risk of burnout and injury because the volume
is very low.

But once you start transitioning from strides into a full length 'R'
workout you greatly increase the risk of soft tissue injury

I'll defer to your experience here.

But if we're specifically talking Daniels, I will say that there's
some variation in "full length" and I find 200m (the short end of "R"
workouts he suggests) radically different from 400+. Doing mostly
200's with perhaps a couple 400's sprinkled in (or not), and taking
very full recoveries, keeps my volume quite low yet still seems very
beneficial. Doing them on the track or dirt keeps the surface soft,
for those of us on the lunatic fringe who consider that a factor ;-)
and being relatively slow probably keeps my AT (and most of
wreck.running's) out of trouble.

"Charlie Pendejo" <[email hidden]> wrote

Quoted message said:

Dan said:

So you can talk blood lactate and non-correlation of intensity to pain
all you want, but I maintain based on the evidence above that there
is an optimal pace to do speedwork at for dx running, and you can
zero in on that pace by feel, and that pace is not painful, just hard.
(Is that sentence worthy of CP?)

Quoted message said:

B.

Humbling, indeed. I can only reach the foothills of your rhetorical
mountains.

Quoted message said:

I haven't been following close enough to guess whether this might be
what Donovan means, but where I see intensity diverging from pain is
when you factor in the durations of the work and recovery intervals.
The intensity at which we can ("optimally"😉 run 200m with 5' recovery
is very different from 800m, 90" recovery or even 200m, 30".

True. However, distance running intervals are not usually done with Extreme
Recoveries, so in practice (and I am a practical person :-) pain tends to
proportional to intensity.

-- Dan

News flash: 2,332 angels can dance on the head of a pin.

--
Posted via a free Usenet account from http://www.teranews.com

Dan said:

pendejo said:

The intensity at which we can ("optimally"😉 run 200m with 5' recovery
is very different from 800m, 90" recovery or even 200m, 30".

True. However, distance running intervals are not usually done with
Extreme Recoveries, so in practice (and I am a practical person :-)
pain tends to proportional to intensity.

I'll have to take your word for what is usual, having almost never
done speed work with a partner or team, and having little idea how
representative the things I've read in books and online might really
be.

And yeah, five minutes recovery is more extreme than I do in
practice. But two to three, sure, if I'm looking for a full recovery
low-lactate low-pain workout. Same pace but cut recoveries to thirty
seconds and I'd be in a lot of discomfort by, oh, I'd think about the
fourth or fifth repeat.

D Stumpus said:

True. However, distance running intervals are not usually done with Extreme
Recoveries, so in practice (and I am a practical person :-) pain tends to
proportional to intensity.

Recovery time does vary a lot, depending on the workout. More anaerobic
workouts tend to involve longer recoveries, so it's advisable not to ignore
recovery time as a factor in workout difficulty. For example, a hill workout
or a 200m reps workout will usually involve "equal distance" recovery (which
is usually about double the time of the rep), whereas a VO2 max track session
usually involves "equal-or-less-time" recovery.

Of course if the recovery times were kept short, you would accumulate a lot of
blood lactate. That is why you don't keep them short.

Cheers,
--
Elflord

In article said:

I did some speedwork today for the first time in several months and
now I'm feeling both puzzled and discouraged. I ran 6x800 meters with
400 meters of recovery between (and after a mile of slow warm up jog).
I aimed for a pace (a Daniels "T pace"😉 based on a couple of recent
races: a good (for me) 5k six weeks ago and a bad 5-miler three weeks
ago. (McMillan suggested a slightly faster pace, by the way).

The pace on a mile basis is about 40 seconds slower than my fastest 5k
time and only about 10 seconds faster than the pace I'd been hoping
for in a half-marathon at the end of the month or about 90
seconds/mile faster than my normal training pace.

Here's the problem: I really struggled to finish the 800s in the
alloted time. I ran the first fast by about 10 seconds but it took
almost everything I had to make it under the wire for the next five. I
wasn't dry-heaving but wasn't that far from it.

One thing is, with your race being the end of the month, there
isn't much biochemical/biomechanical training left to do.

On the other hand, there's still time for a fair amount of
brain training (central governor).

This being the case, I'd worry much, much less about well-computed
workouts (73.2 seconds at Q pace with 36.8 seconds at R pace and
chugging 6.32 ml ouzo, repeat 8 times) and more about re-introducing
your legs to running at racelike paces.

One rendition would be something like 400m at 5k pace, jog 400m,
800 m at 5 mile pace, jog 400m, 1600 m at HM pace, jog 400, and back
down. These are very short duration, very long recovery things.
They won't do a lot to train biochemical pathways. But you can
use them to regain the feel of the paces, and control about
running them comfortably and efficiently.

Differently, 400m at 5k race pace, 400 m jog recovery.

After a several month layoff, it does take time to get used to
running race paces in control rather than in races. Earlier
this year, I started back to the track. First night was 6x800
at 9:00 pace. Some weeks later was 3-4x2000 at 8:00 pace.
Once I build a mileage base, it'll be still faster than that.

Once I have a decent mileage base and have reintroduced my
legs to the paces, 6x800 at 5k race pace with 400 jog recovery,
is, if not pleasant, a good workout. But it does take base
and familiarity with the pace.

--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences