Treadmill
Also called running machine.
What does treadmill training do?
A treadmill is a motorised belt you walk or run on, with speed and incline set at the console. The legs and hips share the work across the stride, and their roles change with walking versus running, pace and slope. Incline can increase the muscular demand of walking; the glutes also contribute to flat running. Track the session in time, pace and incline according to what you want to progress.
How do you use a treadmill?
Set up
- Hold the handrails, start the belt at a speed you can step onto safely, and step on one foot at a time.
Execution
- Once you are steady, let go of the rails and walk or run upright near the middle of the belt.
- Adjust the speed and incline for the session you planned, keeping a natural stride you can control.
- When you are finished, stop the belt with the controls and step off only after it has stopped.
Common mistakes
Holding the handrails once the speed or incline is up
Leaning on the rails carries part of your bodyweight for you, so the incline you dialled in is not the incline you are walking, and it pulls you into a hunched, forward-leaning stride. If you cannot let go, the setting is too much rather than your grip being useful.
Reaching the front foot out to keep up with the belt
Landing with the foot ahead of your hips brakes you on every step, through a nearly straight leg. Take shorter, quicker steps, or slow the belt until your feet land underneath you again.
Stepping straight onto a belt already at speed
The belt pulls your first foot backwards from under you before the second one is down, which is how people go off the back. Start it slow from the rails and bring the speed up once you are walking.
Same speed, same incline, same minutes, every session
An effort you never nudge stops asking anything new of you, the same way a weight you never add to does. Move one variable at a time over weeks — pace, incline or duration — rather than all three at once.
Where it fits in a session
Five to ten easy minutes before you lift, or after the weights — or on its own day — when the cardio is the point rather than the warm-up.
Dose it in minutes and effort, not sets and reps. Easy means you could hold a conversation; make it harder by raising pace or incline, one at a time, across weeks.
Muscles worked
Primary
Secondary
- None listed in this guide
Schematic surface view. Some muscles are partly visible or not shown.
These muscles contribute at different phases of walking and running; the list is not a ranking of growth potential. Speed, gait and incline change the task. Walking uphill increases activity in several hip, knee and ankle extensors. Running also uses the gluteus maximus on a flat surface, and both soleus and gastrocnemius contribute to propulsion and support.
What lifters actually do
About one RepCount lifter in five has logged treadmill work, and it turns up in roughly 3% of workouts — but when it does, it is almost never the workout itself. A treadmill entry sits inside a session of six or seven exercises and is recorded as a single entry rather than in sets, and what it sits beside is machine leg work: leg extensions, leg presses and leg curls, with pulldowns and bench press close behind. That is the shape of a warm-up or a finisher attached to a lifting session rather than of a run for its own sake.
Most often trained alongside
Share of treadmill sessions that also include each exercise.
- Leg extension13.9%
- Leg press12.4%
- Pulldowns12.1%
- Leg curl10%
- Bench press9.9%
Figures come from workouts tracked in RepCount.
Scientific studies on treadmill exercise
Walking, running and walking uphill are different tasks. Research helps explain how those choices change muscle activity and effort, but an immediate response does not tell us how much muscle a training program will build.
Incline can increase muscle activity during walking. Running also uses the glutes on a flat surface, and both major calf muscles contribute. Gripping the handrails can lower the immediate demand at the same speed and incline.
How do walking, running and incline change muscle use?
Ten adults walked at different treadmill speeds and slopes. Uphill walking increased activity in the measured hip, knee and ankle extensors compared with level walking. The changes became larger at faster walking speeds. These were electrical-activity measurements, not measurements of muscle growth.
A separate movement study found substantially greater gluteus maximus activity during running than walking. Flat running should therefore not be described as leaving the glutes largely unused. Nor is running a simple handover from soleus to gastrocnemius: a simulation based on one man running on a treadmill identified both calf muscles as major contributors to propulsion and support. That model explains one tested stride, rather than ranking muscles for every runner.
Does holding the rails change the effort?
Ten adults completed treadmill bouts with free arm swing, hands resting on the rails and hands gripping them. Gripping reduced oxygen uptake and heart rate compared with both other conditions at the tested intensities. The same speed and incline did not produce the same physical demand.
This was an immediate exercise comparison, not a trial of long-term fitness gains. It also does not establish that every brief touch has the same effect. Use support when mounting, dismounting or when you need it for balance.
Sources
Variations
- Incline treadmill walk — Walking uphill increases activity in several hip, knee and ankle extensors compared with level walking.
- Treadmill intervals — Hard efforts alternated with easy walking, with the belt setting the pace rather than your willingness to hold it.
- Curved manual treadmill — No motor — the belt moves only as you drive it, so the effort is higher at any given pace.
- Walking pad — A low, console-light belt built for slow walking, usually under a desk rather than in a gym.
Frequently asked questions
What muscles does a treadmill work?
The quadriceps, hamstrings, glutes, calves, hip flexors and shin muscles contribute at different points in the stride. Their roles change with walking versus running, speed and incline. This is a list of muscles involved in movement, not a ranking of which will grow most.
Does incline change which muscles work?
Incline changes the demand on muscles already involved in walking. A small treadmill study found higher activity in the measured hip, knee and ankle extensors when walking uphill, with larger changes at faster walking speeds. Running also uses the gluteus maximus on a flat surface; incline is not what switches it on.
Should I walk or run on the treadmill?
Choose a pace and gait you can control and want to keep doing. Walking and running are different movement patterns, and both speed and incline change the task. Incline walking is another way to make walking more demanding, but these studies do not establish it as suitable for every injury or painful leg.
Does the treadmill build leg muscle?
The studies discussed here measured muscle activity, modeled muscle contributions and immediate oxygen demand. They did not measure leg-muscle growth from a treadmill training program. They cannot establish how much growth to expect or whether treadmill work replaces resistance training. Workout logs show how people use the machine, not what caused their results.
Should I do the treadmill before or after lifting?
Both are common and both work. A short easy stint before you lift is a warm-up; anything long or hard fits better after the weights, or on another day, so it is not eating into your leg training. In RepCount the treadmill almost always appears inside a lifting session rather than as the session itself, so most lifters are already treating it as the bookend rather than the workout.
How should I log treadmill work?
As a single entry with the time, plus distance or incline if you want something to progress against — not as sets and reps. That is already how it gets logged in practice: a treadmill entry is one logged set almost every time it appears, where a lift is several.
Is the treadmill worth doing if I lift?
About one RepCount lifter in five has logged treadmill work, and it turns up in roughly 3% of workouts — used, but rarely the point of the session. When it appears it sits in a session of six or seven exercises, most often alongside machine leg work, pulldowns and bench press. That is the profile of a warm-up or a finisher, and it is a reasonable way to get some conditioning in without giving up a training slot to it.
Sources
- Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Thigh Quadriceps Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK513334/
- Hu Y, Raja A. Anatomy, Bony Pelvis and Lower Limb, Hamstring Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK546688/
- Elzanie A, Borger J. Anatomy, Bony Pelvis and Lower Limb, Gluteus Maximus Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK538193/
- Shah A, Bordoni B. Anatomy, Bony Pelvis and Lower Limb, Gluteus Medius Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK557509/
- Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Gastrocnemius Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK532946/
- Binstead JT, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Calf. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK459362/
- Juneja P, Hubbard JB. Anatomy, Bony Pelvis and Lower Limb: Tibialis Anterior Muscles. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK513304/
- Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Iliopsoas Muscle. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK531508/
- Franz JR, Kram R.. The effects of grade and speed on leg muscle activations during walking.. 2012. https://pubmed.ncbi.nlm.nih.gov/21962846/
- Lieberman DE, Raichlen DA, Pontzer H, Bramble DM, Cutright-Smith E.. The human gluteus maximus and its role in running.. 2006. https://pubmed.ncbi.nlm.nih.gov/16709916/
- Hamner SR, Seth A, Delp SL. Muscle contributions to propulsion and support during running. 2010. https://pmc.ncbi.nlm.nih.gov/articles/PMC2973845/
- Berling J, Foster C, Gibson M, Doberstein S, Porcari J.. The effect of handrail support on oxygen uptake during steady-state treadmill exercise.. 2006. https://pubmed.ncbi.nlm.nih.gov/17135860/