Your aerobic system will have to handle the increased workload of going faster.
Start training it with Short Interval Training (SIT).
The following routine increased several of the body's systems for increased output in a study.
After at least 5 min warmup - sprint all out for 30 seconds, whatever speed feels max that you can sustain it for the entire 30 sec. You don't want much left over.
Now recover for 4 min, perhaps start with walk and then slow jog then back to normal pace. Recovery will get easier and easier as your aerobic capacity goes up.
Do this for 2 weeks, 3 x weekly, 4-7 sets each time.
Should be rest day or recovery run (badly termed Fat Burn HR zone on Fitbit) the day after.
Keep rest of your run session on after that since this is only about 30 min of time.
Don't mind the misspelled website folder name - this is about the SIT improvements.
https://exrx.net/Sports/HIIT
Now, pace intervals.
Take one of your shorter runs, and after that 5 min warmup aspect again - increase pace for 1 min to say 9 min/mile, or whatever you want to get to that seems desired and reasonable - maybe 8.
Now back down to whatever will let you recover in 4 min initially. Then 3, then 2, ect. Watch HR to know if you have recovered to do your next increase - you may want to base it totally on HR, when HR is back to normal for the slower pace for 1 min, then you increase.
You want to get the body good with running economy at that faster pace.
After a week or two of doing this 2-3 x weekly, you'll probably notice the breathing and HR don't increase nearly as much at the faster pace, or maybe not as much as you'd think it would running faster.
Most people have an efficient running pace, and sadly most when running slower aren't as efficient - but the aerobic system won't allow the faster pace. This routine helps train to find that faster pace.
So don't hold to an exact pace on testing after the 2 weeks, you may find a slightly faster or slower pace just "feels" better (still faster than where you are at though).
Keep the turnover up around 180 and landing mid-foot, and you'll start feeling that springiness that just feels right.
That fast/slow interval routine keeps up for short runs, maybe add it to the longer ones too.
Some people will just start slowly increasing the pace on longer runs, even though not hitting that efficient level for awhile. But keep the training at that faster goal pace somewhere in there.
---------------------------------------------------------------------------------
Help the next searcher of answers, mark a reply as Solved if it was, or a thumbs up if it was a good idea too.
