10 replies to this topic

[Hayls]

Hi all

Does anyone roughly know if I swim a km of swimming what is that equal to in running

I have currently been swimming 4km each day as i am injuired

[Jogger]

I'd always heard 3x but I reckon its 4 (at least!)

[blush]

could you do a time calculation? eg, I swim 2km in around an hour (with rests etc), and run 10km in just over an hour, so does that mean for me its 5 times?? I know I'm a lot more knackered after a 10km run than a 2km swim, but a lot hungrier after the swim!

[Lorax]

Hayls, on Mar 8 2010, 04:36 PM, said:

Does anyone roughly know if I swim a km of swimming what is that equal to in running

10km is generally considered marathon distance in open water swimming. My 10km open water time is roughly in line with my road marathon time so agree with Kevin that somewhere between 3 and 4x is a good conversion. One caveat is that salt vs fresh water makes a real difference in a pool so I tend to be less generous on conversion when swimmining in a saltwater pool.

For what it's worth...

[Paul Every]

I'm not sure how or if one can make a valid comparison.

Just like running, all swimming sessions are not equal. One will obtain much more benefit from swimming a high quality hour with a swim squad than swimming slow laps, so it depends on to what you are comparing it.

How either of these compares to running is problematic. A non-runner swimming 20km/week (a supposed equivalent of running 80km) would probably struggle running a marathon.

Conversely, after a couple of years of marathon running, I decided to take up triathlon and dived in the pool and couldn't complete 50 metres. From competing in swmming events as long as 15km in the '90s, to focusing on my running in the last 10 years, I've seen a steady decline in my swimming.

There is a certain amount of specificity involved in both sports. I don't think either can be seen as a true replacement or equivalent of the other, rather they are, at best, complementary.

Full credit to anyone swimming 4km a day though. I'm sure you will return to running having maintained a solid aerobic base.

[Goughy]

My squad coach got into the tri stuff a bit last year. One of our local tri's she swam the 400mtr (25mtr pool) in 5:30, but did the 5.2k run in 43mins. Different strokes for different folks.

I find them vastly different but love them both!

[Tonic]

I've heard the 4x rule a lot. like 1km swimming equals 4km running which equals 16km cycling.

But you'd better be a good swimmer, cos 4km running sounds to me like a warm-up. 1km swimming sounds huge!

[Hayls]

So if I swam 8km last wednesday, I basically ran 32km????

[Paul Every]

Tonic, on Mar 9 2010, 10:45 PM, said:

I've heard the 4x rule a lot. like 1km swimming equals 4km running which equals 16km cycling.

But you'd better be a good swimmer, cos 4km running sounds to me like a warm-up. 1km swimming sounds huge!

Tonic, if someone has the basic mechanics of freestyle down pat and a reasonable aerobic fitness, they can usually build up to 1 km in a few weeks. For most it would only take 5 to 10 sessions in the pool.

[pastyboy]

Typical swim squad distances would be 2000 to 3000 metres for a 60 min set. Most warmups are 600m to 1000m depending on where you are in the season. It would be pretty rare to do more than 4000m in a set.

Comparing swimming to running is ok at small distances for me. I would do a 4000m open water swim in about an hour and probably 12ish kms running in an hour. But I would never do more than 4km swimming whereas 12km is only a warmup .

As for biking, i'd average at least 30 kmh for an hour.

I reckon comparison is too hard.

[Samo]

The difference is that in swimming the friction from the water results in a need for massive increases in effort/force to achieve a small increase in speed (or an increase in technique to decrease drag and increase glide) and that increase in speed dramatically increases the drag. So to go faster it becomes more and more difficult the faster you actually go. In running you can achieve a relatively significant increase in speed with a far less significant increase in effort. So there are different limiting factors. You also have the whole aspect of elastic energy and the resultant efficiencies if you can learn to use it. Both use large muscle groups though so will achieve good cardiio vascular adaptation. Energy requirements may fit the 4:1 ratio rule but for quality aerobic benefit I would suggest swimming for more than an hour just as in running. Perhaps swimming is more 1:1 with hill sprints??