Not sure if this is the best place to ask this question - well it's kind of two questions I suppose.
At the moment, I run three times a week and cycle twice a week, plus one strength/stretching session. So I work out 6 times a week, but only 3 are running sessions.
In the winter, when it was too dark to run in the morning before work, I was running at lunchtime and going to the swimming pool close to work twice a week (in the place of the two cycling sessions).
I'm thinking about going back to swimming a couple of times a week (it's logistically easier for getting to work a bit earlier and missing traffic etc.) and running at lunchtimes again.
So - the question I have is in relation to swimming. The three running sessions I do are based on the Run Less, Run Faster book - so on a very basic level, 1 x speed session, 1 x lactate threshold session and 1 x long run. All quality workouts. The cross training is kind of in the place of recovery runs. I tried a recovery run recently and landed up injuring my leg... so I'm keen to stick to the 3 x per week for now! So, the question is - what should the effort be like when I'm swimming? I am currently a very slow swimmer. I can swim and swim for ages but at a slow pace. When I was swimming previously, I did introduce some slightly tougher workouts - something like (25m lengths) 1x fast, 1x slow, 2x fast, 1 x slow, 3 x fast, 1 x slow, 4x fast, 1 x slow. "Fast" for me is still very slow, but it was tough going and meant I was out of breath. What would be of the most benefit for running? Just slow and steady for aerobic base building?
Same question really goes for cycling - I now have the benefit of a heart rate monitor I could use when cycling to keep the effort in the right zone if necessary - I generally find cycling pretty easy - I need to be going up a steep hill before I feel any difference in breathing and even then, if I just select a low gear I can cruise up fairly easily. I think my cycling would almost always be in an "aerobic" zone heart rate wise (although I haven't measured yet).