Would Swimming or biking to supplement 70mpw of running HELP or HURT me?

Extra exercise should help your aerobic output, but in my experience, you become a better runner by running. You said you have no desire to push things and seem to be looking for ways to gain a competitive advantage through cross-training. Go for it!

Have you considered supplementing EPO?

You’re better off using the time for strength/core/plyometric work.

I already have strength and plyos in my routine. I'm pretty maxed out as far as running is concerned, short of increasing my mileage. I'm not really willing to risk it as I have had multiple injuries pop up shortly after getting to the 80-85 range.. and I just don't want to deal with that if I can avoid it. So I'll keep the question about if there is a point to adding supplementary aerobic work. I'm trying to find an edge where I could find one.

My experience...

Swimming - if you dont have the upper body strength you cannot get your heartrate up above say 125 for an extended period of time, so although swimming works most muscles in the body in may not be the best aerobic workout. But its great for burning calories and if you swim in a cold pool it really makes you feel tired before sleep because your body is using so much energy to heat itself, so you will get your 8 hours sleep easily.

Of course if you swim a lot you start to get a stronger upper body and then the muscles are working harder and there is more aerobic benefit, but thats a long process if you are starting with a skinny frame like most runners.

To the person who said you should focus on exercises that work the core, well that is exactly what swimming does. As a resistance exercise (water is much denser than air) it strengthens the core muscles much more than running.

Breathing less often e.g. every 4th or 5th stroke will make the lungs stronger as they have less oxygen to work with. Possible vo2 max benefits?

Cycling - builds the quad muscles, great for downhill running and trail running. If you stand up on the bike e.g. uphills you work the calf muscles too.

Seems to aggravate the knees especially if bike is not a proper fit for the rider or the saddle is too low. Runners with history of knee problems should be careful.

Easy to maintain heartrate of 140 or 150 so a good aerobic workout with less stress on the leg muscles. A good way to get more training done and particularly longer training sessions of 2 or 3 hours, without the same impact forces that come with running.

ElliptiGo

As long as it's not replacing running yes. Swimming is a great way to add aerobic capacity while also helping your legs recover after long runs or hard workouts. Front crawl with a light kick, swim faster if you feeling good but easy to moderate is fine for the majority of your laps. 6 hours of swimming a week is a lot for a novice swimmer to just jump into. 3 swims a week (in addition to running) of 1-2 miles is enough for me.

Swimming is painfully boring though, slightly better than a treadmill.

If you know how to swim and can put workouts together in the pool then it’s a great supplement and good to have as a backup if you get injured running. All cardio and no pounding. It’s also a good overall strength workout. It you don’t have swimming background, you will still get a good workout but it’s tough to thrash around in the water for an hour.

What about if I were to train using an arc trainer to get in that additional hour a day of zone 2 work? Would that be preferable to swimming or cycling?

This is purely anecdotal, but high-quality cycling helped my running immensely.

I also have a lengthy history of running injuries, with a long layoff 2019- spring 2022 (surgery at the end of 2019, and then trouble getting PT and medical care I needed in 2020 and early 2021 with covid precautions). But what I did do was get big into cycling, specifically big on Zwift. I already had a good road bike that fit me well. I started putting in 10-15 hours a week in on the bike. I rode 3 hour long rides, raced, did training programs to target aerobic and anaerobic power. I saw my HR and effort decrease at the same power. For example, an hour at 3.0 W/Kg used to be a pretty hard aerobic effort, and my HR might have averaged 140. Now, that same power is a recovery effort, and my HR might average low 120's.

Stepping forward, I finally got back to serious running training in Spring 2022. I've slowly built up to 70 mpw, but still with 3-5 additional hours on the bike per week. Do the math, and timewise, that's worth over 100 mpw. I've run close to PR's in distances from 5 miles up to the marathon. And besides a few minor niggles and injuries that required no more than a week off running, I've been healthy. I also do get in the weight room to lift heavy twice a week, and I'm still going to PT every other week. I think a combination of biking, lifting, and PT exercises have kept me healthy, and close to 100% fitness that could be gained through solely running, with what I believe to be a lower injury risk.

So yes, I think if you do it correctly, additional aerobic crosstraining can be beneficial. LetsRun posters are so hell-bent on "run more mileage," but biking has helped me immensely.

Did you run into any issues with cycling causing your legs to feel like junk while running? What workouts would you recommend to give some stimulus w/o hurting the running side of things? I've always felt a bit fatigued running after biking, whereas i've been fine running after swimming.

Obviously running is the best thing to do to get better at running. But I would think that some additional swimming/biking with your current mileage would only help. I would probably keep it pretty simple & stick with easy aerobic sessions. I've been moving over to triathlon & had hung out around 80-100mpw in marathon builds for the last few years & ran a big half marathon PB this year off of more like 40mpw with a ton of swimming/biking. It's maybe that I was ready for something a lot faster. Not going to claim the triathlon training got me the time versus years of good mileage. I had had a string of injuries that didn't bother me with the lower mileage, which led to a string of good workouts.

If you can pay a reasonable price to train on an AlterG (zero gravity) treadmill, then do that 3 times a week. Or do elliptical.

I'm big on cycling too and do it for 4ish hours a week as a part of a normal training week on top of 60 miles running. In 3 years of this I have only had heavy legs the next day from biking if I went way longer than I was used to. This past XC season I gradually worked up to 3 hour rides on my off day and never felt heavy legs the next. If I bike and run the same day I always run first so can't speak on whether an early morning bike session would make legs tired later for the run.

I've had massive improvement in running from training this way so I would 100% recommend it.

If you want to get better at running, you need to spend more time running. Have you ever seen a kenyan riding a bike?

kipchoge cycles at least weekly. opened a cycling academy recently in kenya.

Thanks man had been looking for something like this. Very encouraging