Sprint Training: Hurt or help aerobic development

One of the criticisms I have seen against the Hansons Marathon Method is that the speed work is in beginning of the training segment because speedwork causes what is known as acidosis. I addressed the question a little bit in the second edition of Hansons Marathon Method. In that discussion, I argued that the speedwork that we are talking about is speed, relative to the marathon. What I mean is that us doing speedwork at 10k pace is fast, when compared to marathon pace. If we were training for a 5k, then no, that same speedwork would actually resemble threshold work. I also argued that doing it early allows us to put the primary focus on marathon pace as the last several weeks approach, a time where the effort needs to be as race specific as possible. In short, I don’t think that the speed work that we are performing creates acidosis at all.

Benefits of Sprinting!
Benefits of Sprinting!

So why bring this up again? I hadn’t planned on it until I came across some articles as I was researching another topic for an athlete. And, since I think it’s always good to have a complete argument, I figured it’s a good time to add to this discussion- even if it’s just me talking to the wind!

Ok, acidosis has been traditionally thought to hurt aerobic development because of things like lowering the blood pH, which would hinder aerobic adaptations. In this case we are talking about peripheral adaptations- enzyme activity, mitochondrial development, etc. However, what we know is that acidosis is only truly a threat if a) you are running above 100% VO2@max and b) spending a lot of time during a session/week at paces of VO2max. This is the basis of my argument. However, what if we did spend time above VO2max? Would it hurt our aerobic development? This is where the articles I re-discovered come into play.

First, let’s discuss what we are essentially talking about: sprinting, simple as that. Some people will call it High Intensity Interval Training or HIIT, which is… sprinting. More specifically, I am referring to repeated bouts of 30 seconds of sprinting in bouts of 4-6 efforts with near full recovery between each and done 2-3 times per week. This is important, because if you are training for a 5k, you might see workouts like 8×600 meters or 8×800 meters at mile pace (or faster) and these are very fast and for 60-90 seconds for fast runners, longer for slower runners. Those are workouts and the 4-6 reps of 30 seconds is a supplement to a run. Extended strides, per say. I think that is key to the whole argument.

So, where’s the proof? I linked a couple of good reads at the bottom of this and you should check them out. These both include references to several studies of interest. The end result is this- In a pretty short amount of time (6-10 weeks) runners of varying abilities performed 4-6 reps of 30 second strides over 2-3 times per week. They found significant improvements in VO2max via peripheral components (with no significant change in central adaptations like heart rate). These are the very same adaptations that we thought would be the victim of acidosis if we engaged in sprinting activities! If we control the length of time and the number of times per week, we not only will avoid hurting our aerobic development, we can:

  • improve neuromuscular connectivity
  • improve strength
  • improve general endurance
  • improve VO2max
  • improve overall speed

As I mentioned, the 30 seconds is key. The 2-3 times per week is key here too. You won’t see the Hansons Marathon Method convert to a HIIT model anytime soon, but there are some serious practical applications for this.

The marathon/half marathon:

  • If you already do strides, try bumping the duration up to 30 seconds from 10-15 currently.
  • Try only once per week to start. This in combination of other SOS workouts is a significant amount of work.
  • If you don’t do strides, start with short 10 second strides and build to 30 seconds over several weeks.
  • I view this as a long term and continual process, so at first it might take longer to see results, but give them time.

The 5k/10k:

  • Here, you might actually do more sprints in the beginning and trail off as you progress in your season
  • With these races, you will actually start training at slower paces and build your actual workouts to a slightly less volume, but greater intensity as you close in on the goal race. This would reduce the need for doing longer sprints more often as workouts, so no need to go beyond 1-2x per week.

Time Crunch:

  • Lower mileage athletes may benefit greatly from being able to incorporate sprints into their week.
  • Another scenario is having a shortened training segment. Let’s say you had something where you took enough time off to lose a little fitness. You are healthy now, but the calendar isn’t cooperating. If you have been doing sprints, you can begin again, and maybe shorten that window needed to regain most of your fitness. I only think this is a safe option if it’s something you’ve done. I don’t condone starting your sprints fresh off a running injury…

Dosages:

  • Start with 1-2x per week and build to 2-3x per week when you aren’t in full training mode.
  • As your workload increases, I would recommend backing down to once per week of 4-6 30 second reps with full recovery. Otherwise, I think a good thing can be overdone.
  • Personally, I would do on a second easy day. So, if you do SOS on Tuesday and Thursday, then I’d do on Saturday before the Sunday long run. Expect to be sore when you first start as you may be finding muscles that have been MIA for awhile.

Good Reads:

Sprint interval training effects on aerobic capacity_ a systematic review and meta-analysis

The Surprsing Aerobic Benefit of Sprinting _ Training Science

An athlete’s question: Hill repeats or hilly run?

I really like these and maybe we should make it a regular part of blogging! I got another great question from Jill, an athlete we wrote a custom schedule for. She emailed me a very simple question that doesn’t have a simple answer: “What is better hill repeats or a hilly run at marathon pace?” Great question! The answer is… Both! Thanks for reading, have a great day!

Just kidding! The answer is both, but for other reasons. Let’s first look at hill repeats. Let’s ask ourselves what the main purpose is of hill repeats is? What is the benefit? Well, we know they’ll make us stronger, so let’s knock that one out of the way. One big aspect of hills is that it is a great form of speed work, or working at close to VO2max effort (not pace). With shorter, but faster hill repeats we are working very close to our VO2max if we are hammering hard up a 1-4 minute hill a few times in a row. You can tell just by how hard that you are breathing that you are working hard, right? With that, we are working on some neuromuscular components as well. With the intense effort, we begin recruiting all of our muscle fiber types to help out. This eventually “opens” up channels to some fast and intermediate twitch muscle fibers that you didn’t even know you had. At the end of the day, think of hill repeats as helping more with overall strength and top end components- lactate buffering, VO2 max, and things like that.

A final note about short hill repeats is that I will use them as gateways towards other workouts. With Boston Marathon people, what I will do is start out with UP hill repeats and a slow recovery back down the hill. Eccentric contractions are crucial for hill running, but they beat you up pretty good in the process. Over time, we’ll adjust and hard UP hill repeats, recover, and then DOWN hill repeats to prepare their legs for the thrashing they’ll get over 26 miles.

What about a tempo run on a hilly course? You’ll get a lot of benefit from theses, both physiologically and structurally. You’ll build your strength obviously, but it’s more like lifting 2 sets of 20 reps of medium weight, compared to like lifting 2 sets of 8 reps as hard as you can with hill repeats. You’ll still get muscle fiber recruitment too, simply because you’ll fatigue your muscles with a fairly intense effort over 30-70 or 80 minutes. For marathoners, that’s great because it’s very race like. These are all great benefits, but to me, one thing we can’t overlook is their eventual impact on our ability to judge effort and pace. For instance, right now, many people have awoken from treadmill hibernation, where they’ve simply set the pace on the hamster wheel and zoned out to their latest podcast of Dateline, or whatever you listen too. Now, they go outside and after letting their eyes recover from the new found sun, realize that there are hills and turns and beautiful scenery. I’m partly kidding, but you know what I mean- we forget and have forgot if we haven’t run in situations where we need to say, “man my pace is slow, but it certainly feels like a hard effort.” I reference back to folks training for Boston. There’s only small section of that course where it’s really flat. It seems like that you are either going up or down most of the time. This means splits will be fast and splits will be slow. It may be hard to find a rhythm. If you’ve practiced pace and effort on hills, then you’ll have more confidence and trust yourself that the effort is there and in the end, the pace will average out.

So there you have it, they are both important but for different reasons. Both have a place in training and can be utilized to your benefit.

– Luke