Price: £499.99 | Motor: 1.25 HP peak (brushless) | Max Speed: 9 mph (14.5 km/h) | Incline: None | Deck: 120 × 42 cm | Max User Weight: 120 kg | Folding: Yes (handlebar folds down)
The Sunny Health & Fitness Slim Interactive Smart Foldable Treadmill is the middle child of JLL’s current treadmill lineup. It is priced identically to the JLL Pegasus at £499.99, offers the same 42 cm belt width as the £399.99 Helius Lite, has no incline, and folds less compactly than either of those machines. So, why not go for a cheaper machine?
Because of its one huge differentiator, a 9 mph top speed driven by a brushless motor, makes it the fastest compact treadmill in JLL’s Sunny range. Whether that extra 1.5 mph over the Pegasus and Helius Lite is worth what you give up to get it is the central question of this review.
Like all of JLL’s current treadmill range, this is manufactured by Sunny Health & Fitness and distributed exclusively in the UK by JLL Fitness from their Birmingham headquarters. Your purchase, warranty, and after-sales support go through JLL’s UK operation.
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Who Is the Slim Interactive For?
This treadmill suits one specific group well: people who want a compact, quiet machine capable of genuine light jogging — not just walking and brisk walking, but sustained 8–9 mph running in short bursts — and who do not need incline or a wide belt. If your workout consists of walking warm-ups followed by jogging intervals at 7–9 mph, and you value a whisper-quiet brushless motor above all else, the Slim Interactive does that job.
It does not suit walkers. If you primarily walk, the Helius Lite does everything this machine does for £100 less with the same belt width and the same brushless motor technology. It does not suit people who want a comfortable, natural walking platform. The Pegasus from JLL gives you a 51 cm wide belt at the same price. And it does not suit anyone who wants incline training, the 12-3-30 workout, or progression beyond light jogging.
But it is a great treadmill if you’re looking for an extremely light, compact, and foldable treadmill that can handle running.
Specs at a Glance
| Specification | Slim Interactive Smart |
|---|---|
| Model Number | SF-T722021 / SFT722021 |
| Price | £499.99 |
| Motor | 1.25 HP peak (brushless DC) |
| Speed Range | 0.6–9 mph (1–14.5 km/h) |
| Incline | None (fixed flat deck) |
| Running Deck | 120 × 42 cm (47 × 16.5 in) |
| Max User Weight | 120 kg (18.9 st / 265 lbs) |
| Programs | 15 presets + 3 custom user profiles |
| Display | Adjustable LED — time, speed, distance, pulse, calories |
| Connectivity | Bluetooth — SunnyFit App (free) |
| Charging | USB port |
| Assembled Dimensions | Approx. 150 × 76 × 119 cm (L × W × H) |
| Folded Dimensions | Approx. 91 × 76 × 119 cm |
| Product Weight | Approx. 43 kg |
| Extras | Bottle holder, device holder, emergency stop clip |
| Warranty | 12+ months (JLL UK) |
The Brushless Motor — What It Actually Means
The headline feature is the brushless DC motor. Brushless motors replace the carbon brushes found in conventional DC treadmill motors with electronic commutation. In practical terms, this means three things.
- First, lower noise — a brushless motor produces significantly less mechanical sound than a brushed motor, making this one of the quieter compact treadmills you can buy.
- Second, less maintenance — no brushes to wear out means fewer moving parts to fail over time.
- Third, smoother speed transitions — the motor delivers consistent torque without the slight surges you sometimes feel on budget brushed motors.
The JLL Helius Lite walking pad also uses a brushless motor with identical specifications, whereas the JLL Pegasus uses a conventional DC motor. So if motor noise is your primary concern, such as for home office users or anyone in a flat with thin walls, the JLL Slim Interactive and Helius Lite share this advantage over the Pegasus.
What the brushless motor does not do is make this a powerful machine. At 1.25 HP peak, this is one of the least powerful treadmill motors on the market. It is engineered for low-speed, low-resistance walking and light jogging. It will handle sustained 9 mph use for shorter sessions, and the motor is perfectly matched to the machine’s intended use — but the intended use is fairly narrow.
9 mph — The Speed That Defines This Treadmill
The 9 mph top speed is what separates the Slim Interactive from every other compact treadmill in JLL’s Sunny range. The Pegasus, also from JLL, caps at 7.5 mph. Similarly, the Helius Lite caps at 7.5 mph. At 9 mph, this machine allows genuine jogging, not just brisk walking with the occasional trot, but sustained running at roughly a 6:40 per mile pace. That is a real workout for most recreational joggers.
Quick-speed buttons at 3, 4, 5, 6, 7, and 8 mph make interval training straightforward. You can jump between walking (3–4 mph) and jogging (7–8 mph) without fumbling with increment buttons. For a compact machine, this level of speed accessibility is well thought out.
However, 9 mph on a 120 × 42 cm deck is a different experience from 9 mph on a full-size treadmill. The 120 cm deck length gives you about 47 inches of usable running surface. At 9 mph, your stride length as even a moderate-height runner will eat up most of that space. Users over 5’8″ will feel the rear of the belt with every stride at anything above 7 mph. Users over 6′ will find sustained jogging at 8–9 mph genuinely uncomfortable — you are constantly monitoring your position on the belt rather than running freely.
The 42 cm belt width compounds this. At walking speeds, 42 cm is adequate. At 9 mph, a 42 cm belt feels narrow. Your natural arm swing tightens, your foot placement becomes precise rather than relaxed, and any lateral drift risks clipping the belt edge. Compare this to the Pegasus at 51 cm or the Reebok Jet 300 at 51 cm — both of which give you room to run rather than room to carefully place each foot.
Incline
There is no incline, not manual, not powered, not adjustable. Which feels hugely limiting at this price point. The deck sits at a fixed flat position close to ground level. This is the same limitation as the Helius Lite and a clear step down from the Pegasus (3-level manual incline) and every treadmill in JLL’s legacy range.
No incline means no 12-3-30 workout. No hill simulation. No way to increase walking intensity without increasing speed. For walkers, this is a significant limitation because walking on a flat treadmill burns roughly 15–20% fewer calories per session than walking on even a modest 3% gradient. For joggers, the lack of incline matters less — your intensity comes from speed rather than gradient — but it still removes a useful training variable.
At £499.99, the absence of any incline is hard to justify. The Pegasus at the same price offers 3-level manual incline. The Reebok GT40z at roughly £399 offers 3-level manual incline. Every comparable machine in or near this price bracket offers something the Slim Interactive does not.
The 42 cm Belt
The running deck measures 120 × 42 cm. This is the same belt width as the Helius Lite and narrower than the Pegasus (51 cm), the JLL T350 (41 cm — though these are comparable), and the Reebok Jet 300 (51 cm).
For walking, 42 cm is workable but not generous. You will walk with a slightly narrowed gait compared to what you would naturally use on a pavement. For jogging at the machine’s 9 mph ceiling, 42 cm is tight. This is not a criticism unique to this treadmill — most compact machines in this price range use similar belt widths — but it does mean the Slim Interactive’s speed advantage over the Pegasus comes with a comfort penalty. The Pegasus lets you walk naturally at 7.5 mph on a 51 cm belt. The Slim Interactive lets you jog at 9 mph on a 42 cm belt. Which matters more depends entirely on how you plan to use the machine.
The deck includes shock absorption, which Sunny describes as providing an outdoor running feel. In practice, the cushioning is basic but functional — it takes the hard edge off each footfall compared to walking or jogging on a hard surface, but it does not approach the multi-point suspension systems used in mid-range Reebok treadmills. For light jogging sessions of 20–30 minutes, the cushioning is adequate. For daily hour-long sessions, your joints will notice the difference from a better-cushioned machine.
Folding and Storage
The Slim Interactive folds by unscrewing and folding down the handlebar assembly. When folded, the dimensions reduce from approximately 150 × 76 × 119 cm to 91 × 76 × 119 cm. This saves roughly 59 cm of floor length, meaningful but not transformative. The height remains at 119 cm regardless of fold state.
This is a less compact fold than either the Pegasus or Helius Lite, both of which fold flat to approximately 15 cm height and can slide under a sofa or bed. The Slim Interactive cannot do this. When folded, it is still a chest-height piece of equipment that needs floor space. Transportation wheels allow you to roll it into a corner or against a wall, but it does not disappear the way a flat-folding machine does.
At 43 kg, the Slim Interactive is lighter than the Pegasus (49 kg) but heavier than the Helius Lite (36 kg). One person can move it on the transport wheels without difficulty. Assembly involves attaching the upright tubes, console frame, and handlebar — roughly 30–45 minutes with the included tools. Lubricate the belt before first use with the included silicone lubricant.
It’s ok, but if you’re looking at folding treadmills there’s better options on offer.
SunnyFit App and Programs
Bluetooth connects the Slim Interactive to the SunnyFit App, which is free with no subscription required. The app provides access to over 1,000 trainer-led workout videos, 10,000+ global walking and running routes, real-time metric tracking, community challenges, and personalised workout plans. This is genuinely good value and one of the few areas where the Sunny products punch above their price point.
Onboard, the Slim Interactive offers 15 preset workout programs plus 3 fully customisable user profiles. The ability to save three different user profiles is a nice touch for households where multiple people use the machine — each person can store their preferred program settings, speed ranges, and workout history. The programs vary speed automatically through each session to create structured interval and endurance workouts.
The adjustable LED display shows time, speed, distance, pulse, and calories. The console angle adjusts for comfortable viewing at different heights, and the device holder accommodates phones and tablets for following SunnyFit workouts during sessions. A bottle holder keeps hydration within reach — a small but practical inclusion that the Helius Lite lacks.
How Does It Compare?
| Feature | Slim Interactive (£499.99) | JLL Pegasus (£499.99) | JLL Helius Lite (£399.99) | JLL T350 (~£589) |
|---|---|---|---|---|
| Motor | 1.25 HP peak (brushless) | 1.25 HP / 2.5 HP peak (DC) | 1.25 HP / 2.5 HP peak (brushless) | 2.5 HP / 4.5 HP peak (DC) |
| Max Speed | 9 mph | 7.5 mph | 7.5 mph | 11.2 mph |
| Incline | None | 3-level manual | None | 20-level powered |
| Deck Size | 120 × 42 cm | 119 × 51 cm | 119 × 42 cm | 132 × 41 cm |
| Max User Weight | 120 kg | 120 kg | 120 kg | 120 kg |
| Programs | 15 + 3 custom profiles | 15 + body fat test | SunnyFit app only | 20 |
| Motor Type | Brushless | Standard DC | Brushless | Standard DC |
| App | SunnyFit (free) | SunnyFit (free) | SunnyFit (free) | None (Bluetooth audio only) |
| Fold Type | Handlebar folds down | Flat-fold (15 cm) | Flat-fold (~15 cm) | Upright fold |
| Weight | ~43 kg | ~49 kg | 36 kg | ~55 kg |
| Extras | Bottle holder, device holder | Device holder, USB charging | Remote control | Bluetooth speakers |
| Warranty | 12+ months | 24 months P&L | 24 months P&L | 5-year motor / 2yr P&L |
| RunRank | 2.0/5 | 3.0/5 | 2.5/5 | N/A (full treadmill) |
The comparison that matters most is Slim Interactive vs Pegasus, because they are priced identically at £499.99. The Pegasus gives you a belt that is 9 cm wider (51 cm vs 42 cm), 3-level manual incline, and flat-fold storage to 15 cm. The Slim Interactive counters with a brushless motor (quieter), 1.5 mph more top speed (9 mph vs 7.5 mph), and 3 custom user profiles. Unless you specifically need to jog at 8–9 mph and the brushless motor’s noise advantage is critical, the Pegasus is the stronger buy at the same price. The wider belt and incline provide daily quality-of-life benefits that affect every single session, while the extra speed only matters during the subset of sessions where you push above 7.5 mph.
Against the Helius Lite at £399.99, the value proposition is equally strained. The Helius Lite has the same brushless motor, the same 42 cm belt width, the same lack of incline, and folds flat rather than upright. For £100 more, the Slim Interactive gives you 1.5 mph extra speed, 15 onboard programs (vs app-only), 3 custom profiles, a bottle holder, and a device holder. If those extras matter to you, the £100 premium has some justification. But if you primarily walk and the onboard programs are not important, the Helius Lite does essentially the same job for substantially less money.
Build Quality and Design
The Slim Interactive uses a steel frame with ABS plastic covers for the console masts, motor housing, and side rails. At 43 kg assembled, it is light enough to move on its transport wheels but heavy enough to feel reasonably stable during jogging sessions. At higher speeds, some lateral movement is expected — this is a compact machine, not a gym-floor treadmill — but it does not feel unsafe or unreliable.
The low-profile deck design keeps the stepping height close to ground level, making it easy to step on and off. The anti-slip running surface provides secure footing, and the emergency stop clip brings the belt to an immediate halt if triggered. The pulse sensors on the handlebars provide the usual approximate heart rate readings — useful for general awareness, not accurate enough for heart rate zone training.
The adjustable LED console is a practical touch. You can angle the display to suit your height and viewing preference, which is more flexibility than most compact treadmills offer. The bottle holder is positioned for easy reach during sessions — a small convenience that adds up over daily use.
Warranty
JLL offers a minimum 12 months warranty on all fitness equipment. The Slim Interactive, as a Sunny Health & Fitness product distributed through JLL’s UK operation, falls under JLL’s standard UK warranty terms. This is the weakest warranty in the comparison set, the Pegasus gets 24 months parts and labour, and Reebok treadmills at similar prices offer lifetime frame coverage.
The brushless motor’s longer theoretical lifespan provides some natural protection beyond the warranty period — fewer moving parts means fewer points of failure — but the formal warranty coverage is not a selling point. JLL’s Birmingham-based customer service remains a genuine positive, providing UK phone support rather than routing you through overseas call centres.
Final Verdict — 2.0 RunRank
The Sunny Health & Fitness Slim Interactive Smart Foldable Treadmill is not a bad machine. The brushless motor is genuinely quiet. The 9 mph top speed opens up light jogging that the Pegasus and Helius Lite cannot deliver. The SunnyFit app is free and provides real value. The 3 custom user profiles are a thoughtful inclusion for shared households. It does what it claims to do, and it does it competently.
It earns a 2.5 RunRank because of what surrounds it. At £499.99, it sits at the same price as the JLL Pegasus — a machine with a 51 cm wide belt, manual incline, flat-fold storage, and a longer warranty. The Pegasus is better for walkers. The Pegasus is better for people in small spaces. The Pegasus is arguably better for most joggers too, because the 51 cm belt provides more comfortable foot placement at moderate speeds than the Slim Interactive’s 42 cm belt does at higher speeds. The only scenario where the Slim Interactive clearly wins is sustained jogging at 8–9 mph by shorter users who prioritise motor noise above all other factors.
Below it, the Helius Lite at £399.99 delivers 90% of what the Slim Interactive offers for 80% of the price. Above it, the Slim Interactive Auto Incline at £599.99 adds 12-level powered incline that transforms the training possibilities. And just £90 above that, the JLL T350 renders the entire Sunny compact range somewhat academic.
Buy the Slim Interactive if you specifically want the quietest possible compact treadmill that can sustain genuine jogging speeds, and the Helius Lite’s 7.5 mph cap is not enough for your workouts. That is a real use case, and for that specific buyer, this machine delivers. For everyone else — walkers, brisk walkers, occasional joggers, space-constrained buyers, or anyone with £90 of budget flexibility — there is a better option in JLL’s own range at every point on the spectrum.
Frequently Asked Questions
Can you run on the Sunny Slim Interactive Smart Foldable Treadmill?
Yes, up to 9 mph. This is the fastest compact treadmill in JLL’s Sunny range. However, the 120 × 42 cm deck makes sustained running above 7 mph uncomfortable for users over 5’8″. The machine is better suited to walking with jogging intervals rather than sustained running at higher speeds.
What is the difference between the Slim Interactive and the JLL Pegasus?
Both cost £499.99. The Slim Interactive has a brushless motor (quieter), 9 mph top speed (vs 7.5 mph), and 3 custom user profiles. The Pegasus has a wider 51 cm belt (vs 42 cm), 3-level manual incline, flat-fold storage to 15 cm, and a 24-month warranty. For most buyers, the Pegasus offers better overall value — the wider belt and incline improve every session, while the extra speed only matters during higher-intensity workouts.
What is the difference between the Slim Interactive and the Helius Lite?
The Helius Lite costs £100 less at £399.99 and shares the same brushless motor, 42 cm belt width, and lack of incline. The Slim Interactive adds 1.5 mph more speed (9 mph vs 7.5 mph), 15 onboard programs, 3 custom user profiles, a bottle holder, and a device holder. The Helius Lite counters with flat-fold storage and lighter weight. If you primarily walk, the Helius Lite is the better value. If you want to jog and value onboard programs, the Slim Interactive justifies the £100 premium.
Does the Slim Interactive have incline?
No. The deck is fixed at a flat position with no manual or powered incline adjustment. For incline training or the 12-3-30 workout, look at the JLL Pegasus (3-level manual), the Reebok Jet 100z (powered incline), or the JLL T350 (20-level powered incline).
Is the Slim Interactive quiet?
Yes. The brushless motor is one of the quietest motor types available in home treadmills. It eliminates the carbon brush friction noise found in conventional DC motors, resulting in significantly reduced mechanical sound. At walking speeds, the Slim Interactive is nearly silent — your footfall on the belt will be louder than the motor. At higher jogging speeds, footfall impact becomes the dominant noise source regardless of motor type.
Does it need a subscription?
No. The SunnyFit app is completely free with no subscription required. The treadmill also works fully in standalone mode with 15 onboard programs and 3 custom user profiles, so you do not need the app or even a phone to use the machine effectively.
How does the Slim Interactive fold?
The handlebar assembly unscrews and folds down using the included tools. When folded, the length reduces from approximately 150 cm to 91 cm. The height remains at 119 cm. This is a less compact fold than the Pegasus or Helius Lite, which fold flat to approximately 15 cm and can slide under furniture. The Slim Interactive requires floor space when folded and cannot be stored under a sofa or bed. Transport wheels allow you to roll it against a wall or into a corner.
Is this the same as the Sunny Health & Fitness SF-T722021?
Yes. JLL Fitness is the exclusive UK distributor for Sunny Health & Fitness products. The hardware is identical — the Slim Interactive sold on JLL’s UK store is the Sunny SF-T722021 with JLL’s UK warranty and customer service. Do not confuse it with the SF-T722022, which is the Slim Interactive Auto Incline version at £599.99 — a different machine with 12-level powered incline.
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