A tempo run is a sustained effort at or near your lactate threshold, roughly the fastest pace you could hold for about an hour, often described as comfortably hard. Typical tempos run 20 to 40 minutes continuously. They raise the pace you can sustain before fatigue sets in, which is why they are a cornerstone of 5K to marathon training.

Fartlek is Swedish for speed play: a continuous run with unstructured bursts of faster running mixed into easy running, based on feel rather than a strict interval plan. You might surge to a lamppost, ease off, then surge again. Structured versions like the Mona Fartlek fix the durations, but the spirit is playful, flexible speed work.

Yasso 800s are a marathon-prediction workout of ten 800-meter repeats with equal-time jog recovery. The idea, popularized by Bart Yasso, is that the time you can hold for the 800s in minutes and seconds roughly predicts your marathon in hours and minutes, so 3:30 repeats suggest a 3:30 marathon. It is a rule of thumb, not a guarantee, but a great fitness gauge.

How many hard running workouts per week?

Most runners do best with two, occasionally three, hard sessions per week, with the rest easy. This is the 80/20 principle: about 80 percent of your running easy and 20 percent hard. Two quality workouts, such as one tempo or interval session and one long run, plus easy running around them, builds fitness while leaving room to recover.

The running workouts that build speed

Updated July 9, 2026 · By the Runked team

Running workouts fall into five buckets: easy and recovery runs, long runs, threshold and tempo work, intervals and VO2 max, and hills, plus short strides and reps for sharpness. Each trains a different system. Mixing them well, mostly easy with a little hard, is what turns miles into speed. Below is a workout dictionary, then how to fit it all into a week.

Junk miles are a myth mostly told by people running every session at the same middling pace. Real training is varied on purpose: some runs build the engine, some raise the ceiling, some sharpen the legs. Knowing what each session is for is half the battle.

Easy & recovery

The foundation. Most of your weekly running should be here, conversational pace, building aerobic capacity without much fatigue cost.

Workout	What it does
Recovery Run	Very easy, short. Promotes blood flow and recovery the day after hard work.
Easy Run	Conversational aerobic base building. The bread and butter of any plan.
Steady State Run	Moderately firm, faster than easy but still controlled. Builds aerobic strength.

Long runs

The weekly endurance builder. It grows your aerobic engine, teaches your body to burn fuel efficiently, and, for marathoners, rehearses time on feet.

Workout	What it does
Long Run	Sustained easy distance. Builds endurance and fatigue resistance.
Progression Long Run	Starts easy, finishes faster. Trains you to hold pace on tired legs.
Long Run with Surges	Easy long run with periodic faster bursts to add quality.
Marathon Pace Long Run	Chunks at goal marathon pace. Race-specific rehearsal.

Threshold & tempo

Work at or near lactate threshold, comfortably hard, that raises the pace you can hold before you fade. The highest-value work for distance runners.

Workout	What it does
Tempo Run	Sustained ~20–40 min at threshold. Lifts the pace you can hold.
Cruise Intervals	Threshold broken into reps with short rests. More volume at hard pace.
Broken Tempo	A tempo split into segments with brief recoveries.
Progression Run	Gradually accelerating from easy to hard across the run.

Intervals & VO2 max

Hard, fast repeats with recovery that push your maximal oxygen uptake and top-end speed. The ceiling-raisers.

Workout	What it does
VO2 Max Intervals	Hard reps (e.g. 3–5 min) near max effort. Raise aerobic power.
Billat 30-30s	30 seconds hard, 30 easy, repeated. High-density VO2 stimulus.
Repetitions	Short, fast reps with full recovery. Sharpen speed and economy.
Strides	Short, relaxed accelerations. Prime the legs without real fatigue.

Hills

Strength and power built through gradient. Hills give the benefits of speed work with less impact stress.

Workout	What it does
Hill Repeats	Short, steep efforts. Build power and running strength.
Long Hill Reps	Longer climbs at threshold-ish effort. Strength plus aerobic work.
Downhill Repeats	Controlled downhill running to build eccentric strength and turnover.

Fartlek

Speed play, faster bursts folded into a continuous run, on feel or to a structure. Fun, flexible, and effective.

Workout	What it does
Fartlek	Unstructured surges by feel. Playful, adaptable speed work.
Structured Fartlek	Fixed work/rest bursts within a run.
Mona Fartlek	Steve Moneghetti's classic 20-min session of descending reps (2×90s, 4×60s, 4×30s, 4×15s) with equal recovery.

Famous named sessions

Legendary workouts that runners chase by name, each a benchmark as much as a session.

Workout	What it is
Yasso 800s	10×800m with equal-time jog rest; the 800 time in min:sec loosely predicts your marathon in hr:min.
Magic Mile	Jeff Galloway's single timed mile used to estimate race paces.
The Michigan	A ladder alternating track reps and road tempo, escalating in pace.
The Lumberjack	A big continuous alternation of hard and steady blocks. A grinding strength session.
Deek's Quarters	Rob de Castella's 400m reps with a short 200m float instead of full rest.

Runked training plan home showing a VO2 Max 1K Repeats session in a Half Marathon Race Prep week — Runked schedules each workout for you, here a VO2 Max session in a half marathon race-prep week.

How to mix them in a week

The single most important rule: run mostly easy. The 80/20 principle, about 80% of your running easy and 20% hard, is what the evidence and the elites both point to. In practice that means:

Two hard sessions most weeks, occasionally three. For example one threshold or interval workout and one quality long run.
Easy or recovery running filling the space around them, plus a true rest day.
Strides a couple of times a week to keep the legs sharp at almost no fatigue cost.
Hard days hard, easy days easy. The classic mistake is running easy days too fast and hard days too slow, so nothing gets trained.

How Runked schedules them

Runked builds these workouts into a personalized plan automatically, with pace targets and effort meters for each session, sequenced through phases from Foundation to Taper. An in-app Types of Run library explains every session, and Training 101 cards cover the science behind them, VO2 max, lactate threshold, running economy, progressive overload and more. Every workout you complete counts toward your rank and feeds your fitness and fatigue metrics.

Training plans are part of Runked PRO (7-day free trial). Tracking, rank, leagues and streaks are free.

Get these workouts scheduled for you

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Frequently asked questions

What is a tempo run?

A sustained effort at or near lactate threshold, roughly your one-hour race pace, described as comfortably hard. Typically 20 to 40 minutes, it raises the pace you can hold before fatiguing.

What is a fartlek?

Swedish for speed play: a continuous run with faster bursts mixed in on feel rather than a strict plan. Structured versions like the Mona Fartlek fix the durations, but the spirit is flexible speed work.

What are Yasso 800s?

Ten 800m repeats with equal-time jog recovery. The time you hold in minutes and seconds loosely predicts your marathon in hours and minutes, so 3:30 repeats suggest a 3:30 marathon. A rule of thumb and a great fitness gauge.

How many hard workouts per week?

Usually two, occasionally three, with everything else easy, the 80/20 principle. One tempo or interval session and one quality long run, with easy running around them, is a proven template.