A lot of people missed the point of the thread. I was talking about preference - not about what gives the biggest fitness gains. I think 90 minute runs and 60/30 doubles both have a place in training plans.
I am not a physiologist, but I can at least give you the layman's reasoning several coaches have laid out to me in the past. I am just relaying my understanding of what more knowledgeable people explained to me. This could be like a game of telephone where I have it all wrong. I'm not laying this out as TRUTH, but I have heard similar ideas from multiple sources (including Wetmore in RWTB where it explains that he prefers the aerobic benefits of his athletes accomplishing most of their summer training volume in singles). If anyone has specific scientific evidence that these ideas are wrong, I would love to hear it and update my thinking appropriately!
-For "easy" aerobic exercise (which we are talking about here with "easy" runs), the body's response in terms of aerobic adaptation to a session of less than ~20 minutes of this kind of effort in a single session is relatively minimal. After ~20 minutes of this kind of exercise, the body's response is more significant in terms of the aerobic adaptations it will make.
-To figure out the "aerobic response time" of a run, subtract 20 minutes from it - again, this is a total layman's description!
-For a single 90 minute run, we would subtract 20 minutes from it to get an "aerobic response time" of 70 minutes.
-For two runs totaling 90 minutes, we would subtract 20 minutes from each run (40 minutes total) to get an "aerobic response time" of 50 minutes.
***For these coaches, from an aerobic development perspective, something like a 30/60 double would be the equivalent of a 70 minute single run. Those two sessions would be different in terms of developing running economy, for example, or from a accumulated fatigue perspective.
I prefer #1 and then #3, and I also believe it's better for my fitness than #4. But I do #4 most often because I train with a team that can't figure out how to double.
90 minutes everyday might be pushing single runs a bit far.
So if I had to choose one option it'd be 60 min b4 work and 30 min after.
It is easier to get out, knowing u only have 60 or 30 minutes to run, than to have 90 as I always felt that after ~10 miles it gets rougher.
That being said:
For all distances between 800 and 10k you will profit more from the easier volume, metabolism boost 2x per day, even if you'd never run longer than 60 minutes at once all week.
It's not about singles or doubles, it's about covering your bases.
When I ran my PRs from 1500 - 5k I usually did 5 + 7.5 doubles (usually like 35 + 50-55'), 2 structured workouts and one or 2 longer runs (12-13 miles) thrown in to get to usually roughly 90-95 miles. Didn't seem to hurt that I only ran 1 hour+ continously only 2 times per week.
This post was edited 5 minutes after it was posted.
Before each run, you need to change clothes, then, after the run, cool down and shower and change again, adding a good 30-45 minutes to the time dedicated to each run. This assumes that it is possible to change and start the run straight from the place where you are, otherwise transit time is added.
I am probably poorly organized, but I find it already difficult to fit my hobby in my normal life of family-work-other interests. The additional wasted time and stress to juggle two activities in a day is not worth the marginal fitness gain. Unless I am on vacation on a tropical resort and bored to death, I always go for 4.
Interesting. For me, the time crunch makes it easier to fit in two 45-minute runs. I don’t have any windows during the work week when I can easily get in a run of more than an hour. The mornings are tight with getting ready for the day and getting to the office by 8:00. Getting up even earlier than I already do to fit in extra time for a 90-minute run would mean sacrificing valued sleep.
After work, I similarly don’t have a ton of time to get home, changed, and out the door for a run before it’s dinner time. I don’t want to eat dinner late because that means going to bed late which means sacrificing sleep. Thus two 45-minute runs are much better for my schedule.
I am not a physiologist, but I can at least give you the layman's reasoning several coaches have laid out to me in the past. I am just relaying my understanding of what more knowledgeable people explained to me. This could be like a game of telephone where I have it all wrong. I'm not laying this out as TRUTH, but I have heard similar ideas from multiple sources (including Wetmore in RWTB where it explains that he prefers the aerobic benefits of his athletes accomplishing most of their summer training volume in singles). If anyone has specific scientific evidence that these ideas are wrong, I would love to hear it and update my thinking appropriately!
-For "easy" aerobic exercise (which we are talking about here with "easy" runs), the body's response in terms of aerobic adaptation to a session of less than ~20 minutes of this kind of effort in a single session is relatively minimal. After ~20 minutes of this kind of exercise, the body's response is more significant in terms of the aerobic adaptations it will make.
-To figure out the "aerobic response time" of a run, subtract 20 minutes from it - again, this is a total layman's description!
-For a single 90 minute run, we would subtract 20 minutes from it to get an "aerobic response time" of 70 minutes.
-For two runs totaling 90 minutes, we would subtract 20 minutes from each run (40 minutes total) to get an "aerobic response time" of 50 minutes.
***For these coaches, from an aerobic development perspective, something like a 30/60 double would be the equivalent of a 70 minute single run. Those two sessions would be different in terms of developing running economy, for example, or from a accumulated fatigue perspective.
Not knocking you, but if these were US distance coaches this might partially explain why we are so far behind the international competition in long-distance events.