Winter Treadmill Speed Sessions (Half Marathon)
Winter Treadmill Speed Sessions (Half Marathon) is a focused collection of key treadmill sessions designed to improve your Half Marathon speed, threshold endurance, running economy and ability to maintain race pace when fatigue starts to build.
Using the treadmill allows you to control pace precisely, remove distractions such as terrain and weather, and accumulate quality time at, and around, your current Half Marathon speed.
This isn't a high-volume training plan. Instead, it's a collection of purposeful quality sessions that can be added alongside your existing running, triathlon or endurance training.
What you'll work on:
🔹 Half Marathon race-pace endurance: becoming increasingly comfortable at your current HM speed.
🔹 Threshold endurance: improving your ability to sustain a strong, controlled effort for longer.
🔹 Faster-than-HM running: controlled intervals designed to make Half Marathon pace feel increasingly manageable.
🔹 Race-pace strength: maintaining pace as fatigue accumulates.
🔹 Running economy: staying relaxed, efficient and technically sound over longer efforts.
🔹 Pace changes: developing the ability to increase effort before settling back into race rhythm.
🔹 Fast-finish strength: learning to maintain or increase pace during the latter stages of a hard run.
🔹 Confidence: making Half Marathon race pace familiar rather than something you only experience on race day.
Sessions use simple treadmill speed targets based around your current Half Marathon Speed (kph), making them straightforward to follow regardless of your current ability.
For example, if your current Half Marathon speed is 13kph, a session prescribing HM Speed + 0.5kph would be completed at 13.5kph.
Recoveries are deliberately controlled. Some sessions use easy jogging, while others progress continuously without recovery. The priority is always maintaining the quality, consistency and efficiency of the race-specific running.
Who is it for?
Our Winter Treadmill Speed Sessions are ideal for runners and triathletes who already have a reasonable aerobic base and want to add structured, Half Marathon-specific quality work to their training.
It can work particularly well for athletes who:
🔹 Have the endurance to complete a Half Marathon but want to race it faster.
🔹 Struggle to maintain their target pace during the second half of a race.
🔹 Want to improve their threshold and speed endurance.
🔹 Need more structured exposure to Half Marathon race pace.
🔹 Tend to start strongly but fade over the final 5–7km.
🔹 Struggle to judge tempo and race pace consistently outdoors.
🔹 Want focused treadmill sessions alongside their normal training.
🔹 Have limited access to reliable flat running routes.
Before starting
You'll need a reasonably accurate idea of your current Half Marathon speed. Ideally, this should come from a recent race, a realistic current race prediction or recent running performances rather than your all-time PB.
Your treadmill speeds throughout the sessions are then calculated relative to this number.
The goal isn't to turn every treadmill session into a Half Marathon race. It's to consistently accumulate quality running at and around the correct speed.
Half Marathon performance isn't simply about endurance, it's about being able to maintain speed, efficiency and control when the legs start getting tired.
Run controlled. Build strength. Hold your pace for longer.
That's our Winter Treadmill Speed Sessions!
WhittleFit provides proven, structured endurance training plans for triathletes, cyclists and runners; from first-time racers through to competitive age-group athletes.
Our TrainingPeaks plans combine over 20 years of endurance-sport experience with practical sessions designed for athletes balancing training with real life.
We have plans for:
- Triathlon
- Cycling
- Swimming
- Running
- Strength Training