Training Plan Abbreviations: GA1, GA2, EB and SB Explained

"3 x 2000 m @ SB, rest 3 min" — anyone reading a structured training plan for the first time runs into a language nobody explains. These abbreviations come from training science, more precisely from performance diagnostics with lactate testing, and they have grown over decades. They are useful because they define three things at once: intensity band, duration and the purpose of a session. If you can read them, you can instantly tell whether the distribution of a plan makes sense — and whether a session fits the goal. This overview explains the common abbreviations, their numeric ranges, and the places where the same letters mean something else.

Why training plans use abbreviations at all

A training plan has to describe a session so precisely that it can be executed without a follow-up question. "Run easy" is not an instruction, it is an interpretation — and that is exactly where the errors come from. Studies on self-paced intensity control show reproducibly that recreational athletes overestimate their effort: what feels "easy" often already sits in the moderate range, which then becomes the well-known intensity hole — too hard for the base, too easy for a real threshold stimulus.

Abbreviations solve this by naming a band that is defined through an objective marker. In German-speaking countries the classic model has six levels tied to lactate concentrations; in English-language literature you will instead find six zones based on percentage of maximum heart rate or on pace. Both systems describe the same thing at different resolution. What matters is not to mix them: Coggan zone 2 is not identical to GA1, even though both mean "easy".

The intensity bands: GA1 and GA2

GA1 — basic endurance 1. The band up to the first, aerobic threshold: roughly 65 to 75 percent of maximum heart rate, around 1.5 to 2 mmol/l lactate. Here the body burns predominantly fat, the fat oxidation rate is at its maximum, and the effort can be sustained for hours. Conversation in full sentences is possible. GA1 is where the decisive peripheral adaptations happen: more mitochondria, denser capillarisation, more economical fat oxidation. That is why the share in any sensible plan is 60 to 80 percent of volume. How to control that share is covered in detail in the article on base training.

GA2 — basic endurance 2. The band between first and second threshold: 75 to 85 percent of maximum heart rate, around 3 mmol/l lactate. The pace is "brisk but controlled", talking only in short sentences. GA2 is often used wrongly — either not at all or far too often. It makes sense as a dosed stimulus: long runs with GA2 segments, progression runs, pace changes. Running 80 percent of your volume in GA2 week after week is the classic mistake of the ambitious recreational athlete.

The distinction matters more in practice than it sounds: GA1 sessions work through volume, GA2 sessions work through dosage. Mix the two and you get neither the volume nor the stimulus.

EB — the development zone at the threshold

EB stands for development zone and is the most important pace band in endurance sport. It sits directly at the anaerobic threshold, classically around 4 mmol/l lactate, corresponding to 87 to 92 percent of maximum heart rate. Colloquially this band is called "threshold" or "tempo"; in English literature it maps to the threshold zone.

The purpose is unambiguous: the effort should be hard enough that lactate production can just about be cleared, and long enough that this state is actually trained. EB is sustainable for 20 to 60 minutes depending on fitness — somewhat longer for well-trained athletes, and over an hour in racing. That makes EB the band that most directly determines race pace from 10 kilometres to half marathon: if you get faster at the threshold, you get faster over these distances regardless of VO2max.

In plans EB appears in three forms: as a tempo run continuously, as threshold intervals such as 4 x 8 minutes with 2 minutes of jog recovery, and as race-pace blocks inside longer runs, for example 2 x 20 minutes in marathon preparation. How to determine the threshold in the field without lactate testing is shown in the article on the lactate test and anaerobic threshold.

SB — the top zone close to VO2max

SB is the top zone: 95 to 100 percent of maximum heart rate, roughly 6 to 8 mmol/l lactate, 2 to 5 minutes of work per repetition. This is no longer about lactate balance but about maximal oxygen uptake and recruiting as many muscle fibres as possible. Breathing is at the limit, talking impossible.

SB intervals are effective but expensive: they create a lot of fatigue, need long recovery and should only appear in blocks within a build — typically four to eight weeks before the goal race, once or twice per week. Proven formats are 5 x 3 minutes, 6 x 800 metres or 4 x 1000 metres with work-to-rest ratios of 1:0.8 to 1:1. Details on effect and dosing are in the article on VO2max training.

Careful, double meaning: in results lists, on portals and in race reports SB stands for season best. Inside a session line it is always the intensity zone. If "SB" appears next to a repetition count and a recovery time, the zone is meant; if it appears behind a time, the personal best is meant.

The other abbreviations that show up in plans

• WSA / WSB — race-specific endurance: race pace or faster over short segments, in the range of 800-metre to 5-kilometre pace. Used only in the competition phase, usually as short, sharp sessions with plenty of recovery.
• TDL — tempo run: a continuous run in EB, 20 to 40 minutes, or in blocks of 3 x 10 minutes. The most race-specific continuous session.
• DL — distance run: a collective term for easy runs, usually 45 to 120 minutes, normally in GA1. "LDL" (long distance run) is the same band, just longer.
• KB / BL — short and long load: older Eastern European interval terminology; KB means shorter repetitions with longer recovery (alactic, close to VO2max), BL longer ones with shorter recovery (lactic, close to threshold). Rare in modern plans because zone naming is more precise.
• FF — fartlek: unstructured alternation between GA1, GA2 and short EB segments by feel or terrain, without fixed recoveries. Ideal for beginners and for days when the watch stays at home.
• STD / St. — strides: 4 to 6 x 20 to 30 seconds brisk to fast, jogging in between. Not interval training but neuromuscular warm-up or the finish of an easy session.
• AL — active loosening: 20 to 40 minutes very easy, often the day after a hard session. Heart rate 10 to 15 beats below GA1.

The bands in one table

The following mapping is the common German-language system. Percentages refer to maximum heart rate, lactate values to capillary blood, RPE to the Borg scale from 1 to 10. Pace offsets are approximations relative to 10-kilometre race pace and serve orientation only — individual variation is considerable.

• Recovery (AL): 60–65 % HRmax, below 1.5 mmol/l, RPE 2–3, pace +50 to +70 s/km on 10 km pace. Purpose: blood flow, no training stimulus.
• GA1: 65–75 % HRmax, 1.5–2 mmol/l, RPE 3–4, pace +35 to +50 s/km. Purpose: aerobic base, fat metabolism, volume.
• GA2: 75–85 % HRmax, around 3 mmol/l, RPE 5–6, pace +20 to +35 s/km. Purpose: aerobic capacity, economy at higher pace.
• EB: 87–92 % HRmax, around 4 mmol/l, RPE 7–8, pace ±0 to +10 s/km. Purpose: shift the threshold, race pace 10 km to half marathon.
• SB: 95–100 % HRmax, 6–8 mmol/l, RPE 9, pace −10 to −20 s/km. Purpose: VO2max, maximal oxygen uptake.
• WSA: 100 % and above, over 8 mmol/l, RPE 10, markedly faster. Purpose: speed endurance, race specificity, sprint ability.

Two practical notes: first, the lactate values are boundaries of a band, not target values — nobody runs "at 4.0". Second, the actual threshold lies individually between 3 and 5 mmol/l, and higher in very well-trained athletes. If you work only with percentages of maximum heart rate, treat those percentage bands as a starting point, not as a measurement.

How to convert the abbreviations into concrete pace

The most practical route runs through a current race performance. From a 10-kilometre time you can derive all training bands with common tables (Daniels, for instance), without a lab. An example: 45 minutes for 10 kilometres equals 4:30 min/km. From that you get roughly 5:05 to 5:20 min/km in GA1, 4:50 to 5:05 in GA2, 4:30 to 4:40 in EB and 4:10 to 4:20 in the SB band. Such tables are a starting point, not the truth — individual spread quickly reaches 10 seconds per kilometre per band.

If you have no current race, use a test: a full 5-kilometre effort, or better a 3-kilometre time trial after a thorough warm-up. Both are more reliable than an estimate by feel. The same principle applies to heart rate: maximum heart rate from the 220 minus age formula scatters by ±10 to 12 beats and is too imprecise for zone control. A field test over three climbs delivers usable values. Details are in the articles on maximum heart rate and in the overview of heart rate zones.

Abbreviation confusion in practice: four mix-ups

• SB as a zone vs. season best: see above — context decides. In session lines with repetitions the zone is meant, behind a time the personal best.
• GA2 as "a slightly faster easy run": many read GA2 as "a bit brisker than GA1" and then spend weeks in a band that neither builds the base nor shifts the threshold. GA2 is a dosed stimulus, not a default pace.
• EB confused with race pace: half marathon pace and EB sit close together, marathon pace sits below. Anyone running marathon long runs entirely in EB trains past the goal.
• Coggan zone 2 equated with GA1: in cycling, Coggan zone 2 is 56 to 75 percent of FTP and considerably wider than GA1. Mix the systems and your boundaries shift upwards without you noticing.

Why Peakora needs no abbreviations — but uses the same logic

The Peakora engine works internally with the same intensity bands, but does not display them as letter codes; it shows the concrete session: "45 minutes easy, heart rate 132 to 145" instead of "45 min GA1". The reason is pragmatic — an abbreviation is only as good as its explanation, and most athletes do not know them. The zone calculation behind it follows the same system: a base share of 75 to 85 percent of volume, threshold once or twice per week, top zone in the competition phase.

On top of that the engine tracks load, which no paper plan can do: CTL as the 42-day average of fitness, ATL as the 7-day average of fatigue and TSB as the difference — your form. These three abbreviations are the only ones worth memorising, because they explain why a plan suddenly gets easier after a hard week. More on that in the article on CTL, ATL and TSB. If you cannot place the abbreviations in your current plan, the Peakora glossary explains the terms of training science one by one.

Frequently asked questions about training plan abbreviations