Speed in the Lydiard context wasn't 800m, 1000m, mile etc etc repetitions at 10K race pace off 60" or 90" rest, which is very common.
Think about it. If you are running 10k race pace, you are not provoking fast twitch muscles or going anaerobic.
So, let's get Lydiard right first. I don't think anyone here actually gets him completely, which is totally understandable. He pioneered this stuff and the language was a little different then and sometimes he sounded as if he contradicted himself. He didn't and he was rarely wrong.
Snell and Lydiard made up and after Snell became a noted exercise physiologist, he was asked what he would change and he answered, "very little."
He did indeed want a little more so-called "speed" but fast twitch stuff. So, for those who are visualising heading down to the track to run hard V02max workouts or LT or AT.....Snell was talking about fast nueromuscular speed-oriented running. He did infact take it upon himself to restart training one year, not with the base phase, but for two weeks before the base phase, a speed phase.....perhaps something closer to Mona fartlek. Then, he started the base phase.
The base or marathon conditioning phase has a weekly fartlek. So, you are never too far away from faster, shorter intervals, but the fartleks were done proper BY FEEL and not measured.
Pre-super spikes, pre-drugs, pre-money on cinder track, the man ran 1:44.1. This is worth 1:42.xx put on the super spikes, add some drugs and goodness knows what he could do.
Lydiard trained a lot of people, then trained coaches and was a national head coach of five different countries. He was knighted in two. Don't kid yourself. He was very right. He made bold and accurate predictions and admitted when he wasn't needed, for example, when he went to Kenya, he said, "they are doing everything right."
If Lydiard's method didn't work for you, it is very likely you weren't quite doing Lydiard. One of his aphorisms is:
Good and bad training can look the same on paper.