The answer depends on how your racing and training is structured over the year. I think it's like you said, if you stay in touch with your speed, this transition is not necessary. But if you've done a long phase of aerobic conditioning, and have lost sharpness and power, the transtion is helpful.From his books, Lydiard called the hill training a shortcut to getting back your speed. I guess this implies not doing hills can still work, but takes longer.If your annual racing/training schedule doesn't permit, he also talked about "racing yourself into shape", where some phases (hill and track?) are cut short, and the races become your speedwork.
RhsRunner wrote:
If the goal of the lydiard hill phase is to regain power and flexibility, can't power and flexibility partially be regained or even improved during base by doing doing alactic hill sprints or by touching on anaerobic endurance by doing repeat 200's at mile race pace effort every 2 or 3 weeks? If this is true, could the hill phase be cut to something shorter than 4 weeks?