How Many Runs Per Week To Increase Fitness/Avoid Injury

There's no correct answer, it varies by person.  An efficient runner who correctly paces themselves (i.e., does not turn every run into a threshold run) can run more than the person who has terrible form and pushes too hard on every run.  There's always a risk of injury, so anyone who tells you "X number of runs is best" is just guessing.  You have to find out for yourself what you can handle.  Start low and increase gradually, and listen to your body while you're figuring it out. 

Running is my worst event. My body just does not like to do it. I run 3x a week, that way I always have 1 day of recovery between runs. Maybe someday I'll get up to 4x, but not until my body can handle two days of running back to back.

it all depends on where you are at and where you want to be with your run.  Dont believe there is a formula that works for everyone.

If you want to be a good runner (not necessarily for a triathlete) you should work up to 6 or 7 times a week,  As far as gaining fitness, I believe in the motto of 4 days to gain 3 to sustain.  The fewer days you run, the more quality there needs to be IMO.  There are three primary types of runs, tempo, long run, and VO2 max types and optimally you will hit a session of each.  That is after you have been running for a few years.  The first couple of years, I would just focus on building up frequency of running and distance (or time) of running. 

Of the three sports, running is my favorite and I would run every day if I could.  Through trial and error I found 3x per week is ideal for fitness and avoiding injury.   In fact, I can support more weekly mileage on 3x than on 4x, etc.  Experiment and find your sweet spot.

for tri training, i have seen the best results in the 6 runs per week range. this is assuming i am training full tiem in the other sports.


injury wise this is going to totally depend on what you are ready to handle/how well you go about it.
frankly, until you have a HUGE base built up, the more you can run without getting hurt the better you are going to do.

2-4x per week might be better to start, and you might keep seeing gains for a while, but if you want to truely see what you can do, it will take more running than that.

there is no set number and it really depends; as you read some of the above posts something different will work for everyone based on your genes, fitness, schedule, goals, distance, etc. If volume and frequency are just main focus just start with 3-4 easy/steady runs and if that feels easy next week add another one and so on. Increase frequency 1st and duration 2nd, IOW build up to do 3, 4, 5, 6, 7 runs x week (ie. 6x 20-30 min easy/steady runs) and once you do all of them and it feels relatively easy start making one of those longs a bit longer and longer each week. (ie. 45', next week 50', 55', 60', 70' etc.)

There are many ways to approach this, the above is just one way...