Is the “Summer of Speed” nonsense for Marathons?

Think about it: for most recreational marathoners, their "5k pace" is basically threshold work. If anything, most of them should be training their "speed" year round.

In this context "summer of speed" roughly translates to "I don't have the dedication to run a lot when it's hot out". They are switching to events where their lack of discipline will be exposed less. From a performance perspective its nonsense.

What makes good training 5k-marathon from a purely performance standpoint is more about a particular individual's aptitudes and development level than it is about the specific event itself. Particularly for recreational athletes we are almost entirely limited by aerobic ability of some sort once the distance is 5k and up, and most of us don't have the aerobic ability to get that close to any sort of "speed" limitation in the 5k.

Yet spending a little bit of time on some aspects of speed year round is still important for pretty much all levels, and even for the marathon.

Now because the influencers themselves and most of the people they are speaking to are a group who tend to struggle with discipline and motivation, the simple novelty of "summer of speed" and similar things may still be a net benefit because it simply gets them training more consistently than they would have otherwise, but it's not an optimal strategy if we disregard that aspect. Influencers in general also always need a "new" thing to be spouting in order to keep generating content. The truth is too boring to get views and peddle whatever latest BS they're affiliated with.

If you enjoy running well-balanced high volume training year-round keep doing that.

I think the answer to this questions depends much on how much you ignore speedwork during your marathon training cycles. If you skip hills sprints, strides, a tepid but important amount of vo2max work during marathon training, than I can see the need to focus on it specifically for several weeks if not a month or two. But proper marathon training shouldn't remove any aspect of a full spectrum of paces. It should just focus the majority of your time/effort/miles on longer efforts. So it then shouldn't REQUIRE doing the opposite to improve your overall speed and fitness.

Now in reality, I'll be the first to admit I don't always maintain the ideal combination of training stimulus throughout the year. But even in that case, don't fall into the trap that a short season of faster training will somehow transform you as a runner, or specifically as a marathoner. Instead, figure out how to better balance your training for the next marathon cycle.

Great answer. The recent thread about Emile Cairess' marathon training that Canova chimed in on really highlighted the idea of covering the full spectrum of paces.

If I recall, Cairess really only seemed to close the aperture and focus on pure Marathon specific stuff for like the last 3-4 weeks of his training block. I believe Jakob also has a relatively short specific phase leading into competitions.

I'm not one to encourage amateurs/hobbyjoggers to copy Pros, but I think trying to hit the spectrum of paces every week (even briefly - as you mention strudes/hills etc.), is a really good lesson and something many should be copying and applying to their own training.

Proper threshold work covers this by including shorter reps (400-1000 in length) with short rest at 5k-10k race pace to allow you to train your economy without burning your legs. There is no real need to do anything more than that and some strides.