Necessity of long runs? (Read 887 times)

    Hey folks, My next marathon isn't until November 10 (Richmond, my third marathon, and for once I'm following a real training schedule .. Hal Higon's Intermediate II). Anyhow, I've been hitting around 30 miles week with a slightly longer run on the weekend. Do I need to do long runs now? I'm not talking really long -- around 12-16ish miles -- but they take a big chunk out of my weekend and I would perfer to spread the miles out during the week. Is there an advantage to long runs if you aren't "in training" yet? Thanks, Trish Smile
    2009: BQ?

    CPT Curmudgeon

      Well, I know that you need to be able to go into the plan running the first week's distances. That being said, you COULD drop them. But, in the long run, you're better off keeping them. You could drop them down in distance, though, or substitute a race of a shorter distance.
        So you think, Scout, if I did a 10-12 miler on the weekends I'd be okay? I don't mind doing that distance ... it's less than two hours.
        2009: BQ?
          Trish, check this out: The marathon long run An excerpt:
          Another aspect of the long, slow run is duration. While running slowly increases fat burning for fuel, another way to really increase fat burning is to run when the carbohydrate stores are lowered. When the carbohydrate stores (muscle glycogen) are lowered, fat burning really goes up since there is little carbohydrate available. We know that the carbohydrate stores are lowered after 90 to 120 minutes of running so you want to do 30-60 minutes of running "after" this to maximize fat burning and to help stimulate the body to store more muscle glycogen for future runs (and races). When running (and racing) for this long, the blood glucose level also lowers. Ingesting carbohydrates (either through a sports drink or energy gels) before and during the run, maintains your blood glucose level. However, as you see below, we may also want to challenge the body to run with a lowered blood glucose level and to adapt to be better at handling a lowered blood glucose level. Therefore, the long, steady runs must last at least two hours and the longer the better and you may want to try to slowly reduce your carbohydrate ingestion before and during this type of long run. Except for a few exceptions, you should try to gradually increase your long run above two hours and I find that long, steady runs of two and a half to three and a half hours are ideal for most competitive marathoners. Running for this long also helps us accomplish two of the other goals for this type of long run. First, with these runs your legs will get very tired but will become stronger and better able to tolerate running for such long periods. Second, you will experience fatigue and have to be mentally strong to simply keep going, knowing that you are going to continue to feel tired. However, it's important to remember that feeling tired is what training is about. You receive many benefits in marathon training only after you're tired. So the goal is to run beyond to the point of being tired so that the body is stimulated to grow stronger and more resistance to tiredness.
          I also remember something similar to this on Hal Higdon's explanation of the "long run" but can't find it right now.

          CPT Curmudgeon

            If you're not in a current training program, and your time is valuable, then yeah, you could stick with 10-12 miles at a shot on the weekend.
              Hey, Trishie: do a search for "long run" threads. There's one around here somewhere that goes into it in excruciating detail, with some interesting stuff on the diminishing returns in terms of value from long runs. Not sure how much of it I buy into - but the debate was illuminating.
              E-mail: JakeKnight2002@aol.com

                I don't buy the tale that stores take 90 minutes to lower. References? Studies? I thought glycogen stores become depleted extremely fast when you do a hard effort. How about doing a short, hard effort, until your glycogen stores get depleted, followed by an easier, longer one? Here's a quote from 'running: biomechanics and exercise physiology applied in practice' indicating that things are not as simple as that:
                The liver and muscles are the storage sites for glycogen. During exercise, glycogen stored in the liver is converted back into glucose so that it can be absorbed by muscles via the bloodstream .. After eating a CH-rich meal, the liver can absorb glucose directly from the bloodstream and store it as glycogen. It can also convert lactate into glycogen ... muscles convert glucose into lactate, which becomes an indirect way for the liver to replenish its supply of glycogen. This phenomenon is called the glucose paradox.
                The paper "Effect of varying exercise intensity on glycogen depletion in human muscle fibres." http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=4083044&dopt=Abstract says
                From start of exercise the average rates of glycogen depletion in type I fibres were about 1.0, 2.0 and 4.3 mmol glucosyl units kg-1 (w/w) min-1 at 43%, 61% and 91% of VO2max.
                So, run steady until you bonk, then take it slow and you'll be mostly running on fat. Of course, as soon as you lower your exercise intensity, lactate will be taken up by the liver, thus giving you more glucose to work with in a few minutes! Also: http://cat.inist.fr/?aModele=afficheN&cpsidt=4972582

                12 Monkeys

                  Okay folks. Step back from your keyboard. We have been through this before. Many times. You ALWAYS burn fat AND glycogen. The proportion relates to your effort. The harder your effort, the higher proportion comes from carbs. The lower your effort, the higher proprotion from fat. But you always burn both. Until you run out of glycogen. And then you stop running. Your body maxes out at about 2000 kcal worth of glycogen. If you are running at a moderately high effort (such as a marathon pace) and weigh 150 lbs, you will burn about 125 kcal per mile, of which about 100 kcal per mile will come from carbs / glycogen. At mile 18-20, you will run low on glycogen and stop running. You. Just. Stop. And you cannot keep going. Sound familiar? Sound like the wall? There is a reason for that. At a lower effort, you will burn more calories from fat and your glycogen will last for more miles. A good ultramarathon effort, you probably get closer to half your calories from glycogen, so you go further before you hit the wall (and eat more). At a higher effort, such as a HM effort, you will burn nearly exclusively glycogen (but still a touch of fat) and may actually burn through your stores in under 13 miles unless you are completely glycogen loaded. Fat burning at a given pace does not go up when glycogen runs out. Nope. Instead, you simply stop running. What you do after that is really glorified walking. And walking is essentially fueled by fat (and a tiny bit of carb). ----- Long runs teach your body - - to pound away for hours - to be more efficient at glycogen burning so that you are able to use more fat at higher effort - to consume calories and fluid while running - to have fun, cuz that is really what it is fundamentally all about

                  CPT Curmudgeon

                    With all that has been said.... Trishie, I think that you can stick to 10-12 milers on the weekends, and suffer no ill effects.
                      With all that has been said.... Trishie, I think that you can stick to 10-12 milers on the weekends, and suffer no ill effects.
                      I agree. The long run is way overrated. Overall weekly mileage is much more important for your long term aerobic development, especially when you are 8 or 9 months from your goal marathon. 10-12 miles as a longest run is fine right now.

                      Runners run.

                        With all that has been said.... Trishie, I think that you can stick to 10-12 milers on the weekends, and suffer no ill effects.
                        LOL, I keep thinking the same thing. For me, even when I'm not in training for something, this is the minimum I want my long run to be. I have to keep some distance in my brain, if I dropped any more miles, I'd be a bit overwhelmed when I needed to pick back up.
                        Jennifer mm#1231

                        12 Monkeys

                          Trishie, I think that you can stick to 10-12 milers on the weekends, and suffer no ill effects.
                          Oh yeah. That too.
                            All of that science makes my brain hurt. Us soon-to-be lawyers don't do well with science stuff ... that's why we're in law school, after all Tongue . Seriously, guys, thanks for the advice. I think I'll stick to 10-12 miles once a weekend until 18 weeks out from Richmond. Trish Smile
                            2009: BQ?

                            Imminent Catastrophe

                              Here's an idea--build up to back-to-back long runs of say, 6 on Saturday and 10 on Sunday. Or 8 and 8, 5 and 12, whatever. Then when you are ready to build for your marathon the long runs will seem easier.

                              "Able to function despite imminent catastrophe"

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