Base – The number of weekly miles that a runner has been putting in. For example, if you’ve been running 30 miles a week, you have a 30 mile base.
Bonking - To "bonk" is to completely run out of energy mid-run. This generally happens somewhere between 17 miles and 20 miles into a run. At this point your glycogen stores are depleted and your legs feel like lead weights. This is also known as "hitting the wall."
Cool down – A slow, easy jog that comes after completion of a workout. A cool down helps loosen the muscles and rids the body of lactic acid, decreasing post-workout soreness.
Fartlek - One of the most fun running terms to use! Fartlek means "Speed Play" and that's just what it is. Inserting bursts of speed into training sessions helps you develop rhythm and form to run faster.
Intervals - Fast bouts of running various distances or times followed by intervals of either active or standing recovery, but not full recovery. Interval workouts can be run anywhere, and do not need to be timed, you can run by feel. Intervals are frequently used to improve vO2 max, but they can be used for other purposes, depending on pace, distance and recovery.
Lactic acid – A substance that forms in the muscles as a result of the incomplete breakdown of glucose. It is the cause of muscle fatigue and soreness and can be greatly reduced with proper cool down and recovery techniques.
Long run – The long run is significantly longer than typical daily runs, and often makes up 20-25% of a runner’s total weekly mileage. The long run is essential for improving endurance levels, building mental strength and teaches the body to burn fat as fuel.
Oxygen Debt - Do you want the real detailed pseudo-scientific definition or the one that matters most? Basically, it's exactly like it sounds. Your body's demand for oxygen exceeds the supply. You are running too hard and your aerobic system can't meet the body's needs. That's where it goes "anaerobic" and lactic acid begins to build in your system, causing fatigue. Unlike your Visa bill, oxygen debt gets repaid through rest and diminished activity.
PR – Stands for “personal record” and also known as a “personal best,” this is your fastest race time for a given distance.
Repeats - Runs, usually on a track, of distances up to 800 meters. Unlike an interval, Repeats have full recovery, usually a jog equal to the length of the run. The objective is to work on form, not on oxygen capacity, unlike intervals. Repeats are run faster than are intervals, and at the same pace regardless of the distance. You can get target times on the Rogue Calculator.
Splits - Times for a portion of the race or workout. So in a 5-mile race you'll have 1, 2, 3, and 4 mile "split." So a 28 min. 5K might have splits of 9:20, 18:20, 27:00 ("27-flat"), 28:00. On a track, a 1600 will have 4 split times and 4 lap times, the latter being the specific time for each lap. A "negative split" is a race or run in which the second half is faster than the first.
Taper – Tapering involves cutting back on mileage anywhere from one day to three weeks before a race to ensure that the body is well-rested and in peak condition for the competition.
Tempo Run - One of those "it depends on the runner and the race being trained for" type of terms. A tempo run involves running at a target pace for a set time or distance and helps the runner get accustomed to that specific pace. Tempo runs can be "steady state" runs of 20-30 minutes, or can be divided up into intervals (see above).
Turnover/Cadence - Stride rate, or number of steps per minute. Efficient runners tend to have stride rates of about 180 steps per minute. Increasing stride rate usually means shortening your stride so that you are running the same pace while maintaining a faster cadence. Changing one's stride rate takes time and requires much focus, but the speed gains are well worth the work.
Strides – Short bursts of speed that generally last for less than 100m and help to improve proper running form and speed.