Adding a training day...due to tendinitis

I have had issues with achilles tendonitis a few times, so I know what you are going through. A few things:

1) Are you sure you have to take two months off of running and cycling? If it's just bothering you here and there, that might not be necessary. And complete rest doesn't always help anyway-- you might find that you get scar tissue forming that still needs to be worked out. With proper therapy (see below) you may be able to still run and bike.

2) Swimming isn't always fine for the injury, but if you find that it doesn't bother it, then certainly you can swim more than twice per week. For some people, if swimming is the only thing that works, they will increase to swimming almost every day. Start by adding a day, then maybe a fourth or fifth.

3) If you really can't run yet, then start off by walking and then run/walk. But you may be able to still run and bike if you keep it easy. No hills, and limited speed work. Trainer work or spin bike can help keep things in control, although some people find outdoor cycling find (lowering the seat sometimes helps). A small heel lift in your shoes can help take pressure off the achilles while running and/or walking while it heals.

4) All this should be best done in concert with treatment from a good physical therapist or athletic therapist-- one who has experience with triathletes and can help you with rehab activities that will keep you moving. Not just the eccentric heel lifts, but various stretching, calf rolling, hamstring rolling, massage/release techniques, etc.

5) If you find you really can only swim and not run or bike, then alternating with a gym routine will help keep you active on other days.

I wouldn't cut your swim volume at all in any individual session. I would add 1-2 more sessions per week doing the same or more volume per day that you are doing now. In fact, if I were in your shoes and truly not able to bike or run, I would commit to a swim-focused training block where I was swimming 5-7 days per week in an attempt to make significant swim gains and build overall fitness.

Swimming is very different from running in that you can go hard, day after day after day. It may wear you out but it shouldn't (if your form is reasonable) be too hard on the body to add significant swimming volume.

Just my two cents

Agree 100% with Jason on the volume here. No need at all to cut back just because you are adding a day or two of swimming instead of a run or bike. The wear and tear on the body is far less while swimming than running. You need to push yourself but swimming 5-6 days a week real hard will not hurt you. I know, I did it for years.

However, I don't think you need to be off the bike that long. I had multiple bouts of AT and was back on the bike pretty quickly, within 2 weeks. A great opportunity to build on your swimming or cycling.

Keep up the exercises even after you are feeling better and roll the tendon often.

Good luck.