I want to get faster. I have tried adding fartleks to my runs and I end up with sore hips for the next three days. I cannot imagine having to take extra days off (or hurt while I sit, stand, or walk) is part of the process. I can imagine that my stride is different or I hit the ground harder when I am trying to go faster and this is part of the problem, but I am out of ideas on how to circumvent this other than quit trying or find something new to do. I'm now frustrated that I am not getting faster, that I feel like I have the hips of an 80 year old, and I think even slow easy runs are probably not advisable. Any thoughts?
Seems like two separate questions to me, but inter-related.
1) Why do I have sore hips after speed work?
I'm not a Dr or PT, so I certainly can't say for sure. How debilitating is the hip soreness? Because I certainly don't feel super great right after a speed workout. And after races the soreness can certainly linger for days. It's hard for me to say whether the soreness is expected or unexpected. Like, after a hard workout, my body generally has no plans on agreeing to another hard day for a few days. My body in general is sore all over. The easy runs post-hard days feel a lot stiffer than pre-hard days. But an easy run normally causes me little to no soreness and I could go and do another easy run in 24hrs or less.
Sounds like the issue is bilateral. So possibly not a cambered road or having something in one hand in not the other (like a water bottle). Maybe a shoe thing? Do your older shoes need replacing, or possibly a different pair of shoes would be better for speed work? I think strength work, cadence, and running form are also great places to look as suggested prior. I'd also look at the structure of your fartleks. Since by definition it just means "speed play", fartlek is a pretty general term which can lead to a nearly limitless number of workout structures. So when you're doing speed play, what are you doing during the workout? What's the pace relative to current fitness, interval rep, resting interval duration/distance, running interval duration/distance, warmup and cooldown distance/duration and pace? Or is it simply a "feel" type speed play where you just go out and speed up/slow down whenever it feels right with no data to review? Is there a pace between "easy" and "fartlek" that does not cause problems? Is there a sustained pace that doesn't cause issues, but once you cross pace "x" is generally when your hips get sore post-run?
2) How can I get faster?
In my opinion, the number one way to get faster is consistency. The more consistent you are over weeks, months, and years the faster you will get.
Behind consistency, I would say running at an appropriate pace based on your current fitness level. With the overwhelming majority of training being slow as to not impede your ability to do the hard days well and to still reap underlying benefits.
And probably thirdly, I would say structured progressional training plans. Structured does not mean it has to occur on M, W, F, Sa every week as I believe you've stated in the past that a set weekly schedule wouldn't work for you personally. Structured simply means that in a given week you have certain workouts to accomplish. So maybe 4 workouts a week and one week it is M, T, Sa, Su and a different week is W, R, F, Su. Additionally, that in six consecutive weeks (or different sized smaller/larger mini-cycle blocks) you have a certain type of workout that you do. And that workout over the course of the those weeks gets progressively and incrementally more difficult. This progressional structured style forces your body to make small but manageable adaptations over the course of several weeks. Such that the workout in week 1 might have been difficult, but by the time you get to Week 7 if you were to do the same workout it wouldn't be nearly as difficult. How a workout can become more difficult over weeks is by manipulating the key components. Either pace, duration at pace, volume at pace, resting interval duration, or resting interval pace. Something like:
3 x 1 mile HM Tempo w/ 0.5 mile RI
2 x 1.5 mile HM Tempo w/ 0.5 mile RI
2 mile HM Tempo + 0.5 mile RI + 1 mile HM Tempo
3 mile HM Tempo
In the case above, the pace (HM Tempo), volume at pace (3 miles), resting interval pace (slow), and resting interval duration (0.5 mile) are held constant. The only variable that is changing over the course of several weeks is the duration at pace. You're going from the same total volume split over several intervals to at the end doing the same volume but in one continuous bout. In general, you try and change only one, maybe two, of these variables at a time when the plan progresses during one of these mini-cycles. Progressing it too quickly can lead to a struggle for your body to either complete the workout or adapt appropriately to it.
And lastly, volume of training. Injuries and overtraining not withstanding, the more training you do, the faster you will be. There is obviously a limit to this. And this is something that should/can be progressively built over several training cycles/years. So while you may only be able to handle 4-5 hrs now before you get overly fatigued. Maybe in 1-2 years you could handle 6-7 hrs before you get overly fatigued. But generally speaking, more training will yield faster results. Once you start to get in the >9-10 hr a week range for running is when doing doubles has to be strongly considered. Because much more than 60 min in a run starts to infringe on its ability to still be defined as "easy". So that's when doing a 60 min morning run and 30 min evening run is "easier" than a 90 min evening run even at the same pace.
Great job 
