What is the science behind doing doubles over singles?

^scroll down to "Reasons for Doubles"

if you have extra time, read the entire thread as well

en,thanks for sharing

Help Please wrote:

I am thinking about getting more into doubles as I have heard they can really help your training, but why exactly are they better than singles? Is there a scientific answer to why doubles are better for runners than singles? Thanks in advance!

It's a basic principal of aerobic loading.

education wrote:

http://www.letsrun.com/forum/flat_read.php?board=1&id=192559&thread=192559

^scroll down to "Reasons for Doubles"

if you have extra time, read the entire thread as well

Um, that's not exactly "science".

education wrote:

http://www.letsrun.com/forum/flat_read.php?board=1&id=192559&thread=192559

^scroll down to "Reasons for Doubles"

if you have extra time, read the entire thread as well

A letsrun thread does NOT constitute sound science at all.

I do believe, according to Lydiard, singles are more beneficial aerobically. I do not have a peer reviewed study to cite on that tho. Doubles are ok i guess if u are injury prone or maybe short on time. In my experience, 80-85mpw is the cutoff where doubles become easier for a couple days a week, but that doesnt mean they are better.

Lydiard favored longer runs. He always said that running for an hour twice a day wasn't as good as a single two hour run. BUT, he was ALWAYS an advocate of running twice a day.

I'm not gonna track down papers for you but, 2/days can make you body send out 2 flushes of hormones (e.g. HGH, IGF...) that stimulate adaptation. This is why even extremely slow 'shake out' runs can be beneficial.

Wwjd running group wrote:

I'm not gonna track down papers for you but, 2/days can make you body send out 2 flushes of hormones (e.g. HGH, IGF...) that stimulate adaptation. This is why even extremely slow 'shake out' runs can be beneficial.

^this.

Here's an article:

"Skeletal muscle adaptation: training twice every second day vs. training once daily"

http://jap.physiology.org/content/98/1/93.full

Good article that, thanks.

The way i look it is like this:

You build up of course and at some point you are running an hour.

To continue building up do you increase beyond an hour or start a second session?

For me it all depends on the purpose of the session.

Some more reading from Steve Magness:

http://www.scienceofrunning.com/2009/10/is-9mi-once-better-than-45mi-twice.html

Personally, I don't think 80-85mpw is that hard when doing easy runs. However, how do people do workouts after running 10-12 miles in a single run the day before? I'm dead for workouts after even running 8-10 miles the day before in a single run. So I do 12 miles split into two runs (8 and 4) before workout days. Actually, I do doubles almost every day so keep the legs fresh and to reduce injury risk even though my normal mileage is rather modest. (~70)

no science wrote:

I do believe, according to Lydiard, singles are more beneficial aerobically. I do not have a peer reviewed study to cite on that tho. Doubles are ok i guess if u are injury prone or maybe short on time. In my experience, 80-85mpw is the cutoff where doubles become easier for a couple days a week, but that doesnt mean they are better.

Brian123 wrote:

Some more reading from Steve Magness:

http://www.scienceofrunning.com/2009/10/is-9mi-once-better-than-45mi-twice.html

Cheers again. I like what that guy is saying. So what is he saying?

He has observed closely a lot of teenage school athletes over a number of years. He found in these athletes, regardless of whether they run singles or half distance doubles, there is no real difference in performance.

He found studies which show the growth hormone production increase during exercise and how there is a leveling off after 40 mins through to 60 mins (when i assume it has leveled off completely). This provides a reason why doubles have the same effect on aerobic fitness as running singles. He says this is counterintuitive because he would have expected singles to have a bigger effect.

He then comes to realise that the only way doubles can replace singles effectively is if the aerobic system is being challenged in other sessions. The thrice weekly or every second day session and the weekly long run. The former i assume to pressure the aerobic system and the latter to extend it.

So basically doubles are good some of the time and only if an all round program is being followed.

I think i like doubles most days, however, i wouldn't like those on the same day to be the same type of session.

*What i found really interesting was the Growth Hormone Analysis. If it trails off after 40 mins then those 40 mins are easy money in the bank. This could be why i often feel like stopping around 45 mins and so use that distance for recovery pace runs. It could also be why 60 mins is such a standard everywhere you look.

The other interesting thing is that those extra 20 mins gain the athlete another increase of 50% on top of the 550% increase already occurred. This might not seem much, yet we are talking about track and field aren't we? Where winning margins are measured in seconds, tenths, hundredths and personal bests are treasured due to their infrequency and increasingly smaller improvements. Within that extra 50% is one of the main differences between the constant improver and the one who is stagnating surely.

One thing that isn't mentioned in that article is that splitting a day's mileage into two runs probably means lower chance of injury. Assuming all else (like pace) is the same.

Summer of Malmo thread is also worth reading.

Help Please wrote:

I am thinking about getting more into doubles as I have heard they can really help your training, but why exactly are they better than singles? Is there a scientific answer to why doubles are better for runners than singles? Thanks in advance!

Wrong discipline. You don't need scientific reasons. You need mathematical ones. For example, the fact that, say... 90 miles per week is greater than 70 miles per week. And the fact two hours and 30 minutes for a marathon is less than 3 hours

I think ideally people would want to do singles because of the higher aerobic benefit. The only problem is that most people have school or jobs so they run beforehand and then after to fit in enough training time, but if they had the option I believe they'd limit it to one run

The Waterboy wrote:

I think ideally people would want to do singles because of the higher aerobic benefit. The only problem is that most people have school or jobs so they run beforehand and then after to fit in enough training time, but if they had the option I believe they'd limit it to one run

I'm not so sure about that. Don't MOST elites run doubles?

Here is another good thread on the subject.