Running is bad for people who run badly, as in land on their heels first.
Fartlek means "speed play" so is basically just altering your speed whilst running, if you run outside on normal terrain you will be fartlek training, as you will come across hills etc. which produces the same effect.
As she said long slow-distance running suits her HIIT isn't the most effective method. aa
Run for as much as you can comfortably in one week, for example lets say 1hour 4 times a week then increase your total time by 10% each week. Which means after a month you'll be running for 2.5 hours more per week(roughly) than you were at the beginning.
a
Contrary to what somebody said, you shouldna't notice improvements in fitness come every session, infact its quite likely that a few sessions will feel harder than they usually do - when this happens, you should still complete the required distance/run for the same amount of time, just do it at a lower intensity - ie. just run slower.
Noticeable improvements in your fitness will occur in about 6 weeks I reckon, the best way is to test yourselfa using a series of tests.
For example, to test your aerobic fitness you might want to do a 10k run or a 5k run, to test your anaerobic fitness maybe a 1mile run/1500m?
You'll know if you're getting fitter or not when your times improve, if they start getting worse though its a sign you're doing something wrong, which is why it is a good reason to test yourself regularly.