I primarily race and train for 70.3s. I've always been a swimmer my whole life and some hardcore trainer workouts have improved my riding ability over the past couple of years. My problem is that I'm significantly limited by my inability to run fast. Right now I'm about a 1:52 for 13.1 miles. My goal for the summer is to go under 1:30. So I've put away the bike and the pool for the next 10-12 weeks to focus on running. As I was out running today I was thinking about my step/stride length and cadence. My main question is whether there is an optimal step/stride length for runners based on leg length and height and cadence? My cadence currently averages about 82 and I'm 5'10 with a longer torso and 31" inseam. Are there other running form components that will help me in my quest to run faster that you might recommend? Thanks for your help.

May I ask what is your weight? At 5'10" the ideal weight for most is to be slightly under weight near 145lbs. The range is 145lbs to 165lbs. If you are closer to 165lbs or a Clydsdale at 175lbs running your fastest 13.1 miler may be near impossible. Most of your elite runners are going to be slightly under weight for their height. Most will have legs that are proportionally 3x bigger than their torso.

A few things that can help lower your race times is,

1. If you have a nuetral gait where racing flats. For every 1oz you can shave off your shoe weight, you will gain 2 seconds per mile.

2. Learn how to midstrike when running. When you midstrike, you will have better running economy, you will use less energy, and you will run faster with higher turnover.

3. Doing intervals of 200m, 400m and 800m and doing all of those, not just one like 800m but you must do the 200,400,800m once every 2 weeks. Unless you do intervals your race times will never go down. Tempo runs are good and have their place but nowhere near as good as intervals.

4. For half marathon training, your longest run should be 17 miles and a slow buildup. Insert some tempo runs inside those miles.

5. Lead yourself out. You should try to reduce your total fat until you get to like 5% body fat if you can. Having fat requires oxygen so it is less for your running muscles.

6. Don't sign up for half marathons where temp is over 50 degrees. For every 5 degrees over 50 you will slow down 10 seconds per mile.

the other thing to keep in mind, how fast you can run any distance will be largely determined by genetics. So try as you may, some may never be able to do a sub 1:30 half marathon. Some people are really good at the short 1500m or the 5K distance because they have a lot of fast twitch fibers but will be bad at the longer stuff like full marathons. Some will really be good at marathons because they have a lot of slow twitch fibers, but not so fast at short 5K races. My best distance is 5K race, my second best distance is half marathon as I did 1:28:00 for my Half PR but I was 145lbs. The full marathon has never been my distance and I have bonked at every one. At 164lbs there is no way I could run 1:28. 5K may be a different story because I have seen some pretty big bulky guys run that fast but at half marathons, generally you will have to be like super thin.

I stand by my post. Op is not training for a marathon and is also not close to maxxing their run ability at a 1:50 hm.

Just run more.

Fwiw - I run marathons neat 7:00 per mile and just came off a block averaging 75mpw for 5 months so I'm well aware of what you are referring to. It's legit but op likely needs simple volume first.

I think the OP did mention he was trying to get under 1:30 for a half marathon if I am not mistaken. So by him making that statement, if all he does is run a 9:00 pace and runs no more than 30 miles a weeks as you suggest, if he running 5 miles a day? If that is the case he is not prepared. Or is he running 15 miles 2x a week to make 30? If he is just jogging and slugging along at 9:00 pace I don't see how he can do a 6:52 pace to be around 1:30. That is why I was saying if he is looking for a specific time goal for a half marathon he has to do the long run(16miles), intervals and tempo runs but intervals are far more important then even tempo runs for this distance even though he will be running near threshold (tempo run pace). They did a study where experts took 5 runners where all they did was track workout intervals and another 5 runners who only did tempo runs. The group that only did intervals had faster and faster race times where tempo runners didnt improve at all.

But anyway, I think too many people including myself we get obsessed with race times. I can no longer run like I used to and today I just run for fun and I run slowly.

I primarily race and train for 70.3s. I've always been a swimmer my whole life and some hardcore trainer workouts have improved my riding ability over the past couple of years. My problem is that I'm significantly limited by my inability to run fast. Right now I'm about a 1:52 for 13.1 miles. My goal for the summer is to go under 1:30. So I've put away the bike and the pool for the next 10-12 weeks to focus on running. As I was out running today I was thinking about my step/stride length and cadence. My main question is whether there is an optimal step/stride length for runners based on leg length and height and cadence? My cadence currently averages about 82 and I'm 5'10 with a longer torso and 31" inseam. Are there other running form components that will help me in my quest to run faster that you might recommend? Thanks for your help.

I'm gonna simplify it a lot more than the above (and likely be right).

Run more. A lot more and more regularly than you are now. 30+mpw for HIM sounds right for starters, but if you can take a dedicated run block to crank it to 50, you'll see a lot of benefit.

Running at these BOMOP to MOP AG speeds is all about volume and consistency. You don't need special speed workouts, stride drills, or anything else save run more miles.

I am sorry but you are totally wrong. Talk to any running coach or for that matter, get any good book on running and the 3 key workouts for marathons are the following And elite runners also do the same training as non elites, but at a much higher level and much more of it.

1. Interval Track workouts (this will bring your race times down all across the board any distance. Cardio fitness will improve aerobic capacity, leg strength, and will activate the slow and fast twitch muscle fibers.

2. Tempo Runs: this is the bodies ability to use lactic acid to use as fuel and allow the body to run through tired legs. It also pushes that wall further, thus enabling the runner to hold a hard pace

3. Long Run- This allows the body to drain its reserves of glycogyn to teach the brain to store more of it so you can push the wall further. Everybody has enough glycogen to run 20 miles before hitting the wall but a way to push that wall further forward is to teach the brain to store more glycogen. How do you do that? On your long run, you don't eat dinner the night before full of carbs and you don't eat carbs for breakfast. You want to low carb your trianing so you teach brain to store more of it.

Anyway for other distances like 5K, again you are totally wrong to think you don't need special training. 5K specialists focuses on more intervals per week then say a marathon runner. They also run shorter distances like 6 miles but they are more intense. Anyway I can go on and on but there is no such thing as you just run run run.

The only thing I will agree with, yes it is true if you run at least 50 miles a week(30 miles is not enough for most marathon training programs), and you run the 50 miles slow, yes you can finish a marathon but if you want to PR and run it to your bodies best of its abilities, then you will need to do intervals, tempo runs, and long runs. There is no substitute for that

Sorry but you're wrong. OP will benefit more from increased mileage than harder workouts. The way to do it is first increase mileage and then start doing workouts. Also the 5k is not a fast twitch event.