Running Glossary

Aerobic Base

Your body's ability to sustain effort using oxygen. A strong base means you can run longer and faster before shifting into anaerobic metabolism. Built through months of easy miles.

BQ (Boston Qualifier)

A marathon finish time that meets the Boston Athletic Association's qualifying standard for your age and gender. Meeting the BQ standard is necessary but not sufficient, recent cutoffs have required running 5-6 minutes faster than the standard.

Carbohydrate Loading (Carb-Loading)

The practice of increasing carbohydrate intake in the 2-3 days before a marathon to maximize muscle glycogen stores. Standard protocol: eat 8-12g of carbs per kg of body weight per day.

Corral

A designated starting zone in a mass race, assigned based on predicted or qualifying finish time. Starting in your correct corral prevents early congestion and traffic from slower runners.

CR (Course Record)

The fastest time ever run on a specific race course. Distinct from a world record because course certification and conditions vary.

Cutdown Run

A training run where each successive mile or segment is run faster than the previous one, starting at an easy pace and finishing at or near marathon pace. Builds pacing discipline.

DNF (Did Not Finish)

Withdrawal from a race in progress. Does not count as a qualifying time for any subsequent race.

DNS (Did Not Start)

Registered for a race but did not begin. Different from DNF; applies to injury, illness, or logistics.

Easy Pace / GA (General Aerobic)

A comfortable, conversational effort, you can speak in full sentences. Typically 60-70% of maximum heart rate. Forms the majority of weekly mileage in most structured training plans.

Fartlek

Swedish for 'speed play.' An unstructured workout alternating faster and slower segments at the runner's discretion, often done on trails or roads without formal intervals.

FTP (Functional Threshold Pace)

The fastest pace you can sustain for approximately one hour. Similar to lactate threshold pace. Used in some plans as a proxy for tempo/threshold effort.

GFA (Good For Age)

A non-ballot entry category for races like London Marathon. Awarded to runners who have completed a marathon within the age-specific GFA standard time.

Heart Rate Zones

Training intensity categories defined as a percentage of maximum heart rate (HRmax). Zone 1-2: easy/aerobic. Zone 3: moderate/tempo. Zone 4: threshold. Zone 5: VO2max/sprint.

LR (Long Run)

The weekly cornerstone workout, typically the longest run of the week. Builds aerobic capacity, fat-burning efficiency, and mental endurance. Usually run 60-90 seconds per mile slower than marathon pace.

LT (Lactate Threshold) / Tempo

The fastest pace you can sustain for a prolonged effort (roughly 1-hour race pace). Running at LT pace for 20-40 minutes per session raises your threshold, making marathon pace feel easier over time.

Marathon Pace (MP)

Your goal race pace for a full marathon. Pfitzinger defines MP workouts at 97-103% of marathon pace. These runs train your body to run efficiently at race intensity.

MLR (Medium-Long Run)

A midweek run of 13-17 miles in Pfitzinger plans. Builds aerobic endurance without the full recovery cost of a Sunday long run. Typically run 10-20% slower than marathon pace.

Negative Split

Running the second half of a race faster than the first. Associated with better marathon outcomes: a 1-3% slower first half typically produces a stronger finish.

OA / AG (Overall / Age Group)

Overall finishing place among all runners; age group finishing place among runners in your 5-year age bracket.

Overtraining Syndrome (OTS)

A state of cumulative fatigue from training load exceeding recovery capacity. Symptoms: persistent fatigue, declining performance, mood changes, frequent illness. Recovery requires weeks to months of reduced training.

Pace Zone

A speed range associated with a specific training effort or physiological benefit. See: Easy, GA, MLR, LR, MP, HM, LT, VO2, Stride.

PR / PB (Personal Record / Personal Best)

Your fastest time at a given race distance. These terms are interchangeable; PR is more common in the US, PB in the UK and internationally.

Race-Specific Fitness

Fitness adapted specifically to marathon demands: glycogen efficiency, fat oxidation at marathon pace, heat management, and mental endurance. Develops in the final 8-10 weeks of a build.

Recovery Run / Rec

A very easy run done the day after a hard workout or long run. Promotes blood flow, clears metabolic waste, and maintains mileage without adding training stress. Should feel completely comfortable.

Riegel Formula

A mathematical model (T₂ = T₁ × (D₂/D₁)^1.06) that predicts race times at different distances based on a known result. The exponent 1.06 accounts for increasing fatigue at longer distances.

Split

The time taken to complete a segment of a race, typically each mile or kilometer, or a half of the total distance.

Strides

Short 20-30 second accelerations at near-sprint pace (not full sprint) with full recovery between reps. Done after easy runs to maintain neuromuscular speed and running economy without significant fatigue.

Taper

The planned reduction in weekly mileage in the 2-3 weeks before a goal race. Allows accumulated fatigue to dissipate while maintaining fitness. Typical Pfitzinger taper: 80% week 2 out, 55-60% race week.

VDOT

Jack Daniels' performance-based measure of aerobic capacity, calculated from race times. Not a direct VO2max measurement but highly correlated with it. Used to assign training paces for all workout types.

VO2max

The maximum rate at which your body can consume and utilize oxygen during intense exercise, expressed in mL/kg/min. Higher VO2max correlates with better endurance performance. Improved by interval training at 95-100% max effort.

VO2 Intervals

Repetition workouts run at 5K race effort (95-100% of VO2max). Typically 600m-1600m repeats with equal-distance or time recovery. Most physiologically stressful workout type; 1-2 per week maximum.

Watts (Running Power)

A measurement of running effort calculated from speed, slope, and body weight. Increasingly available on GPS watches and running power meters. Allows effort comparison across varied terrain.

WR (World Record)

The fastest officially ratified time for a given distance. Marathon WRs: Eliud Kipchoge (Kenya) 2:00:35 (men, Berlin 2023); Tigist Assefa (Ethiopia) 2:11:53 (women, Berlin 2023). Breaking 2 hours in official competition remains unachieved.