The phrase “long run” gets thrown about a lot: on our training plan as we hit marathon race-prep, when the algorithm tells us to join someone as they do their weekend SLR (Slow Long Run), and even when we simply try to build more stamina and endurance for hybrid events like Hyrox.
But here’s the thing: what actually counts as a long run? And what pace should you be doing them at?
For some runners, that long run is all about hitting double digits for the first time. For others, it’s a 30K training session before marathon taper week. It’s different for everyone.
Often slotted in at the end of a busy week, your long run can either feel like a test, or it can be the run you look forward to. Regardless of whether you love, or hate them, long runs are the training session that quietly do the heavy lifting for everything else you need: speed, stamina and mental grit.
But can we make them better? Let’s break it down together: how long should your long run be, when is actually the best time of week to run long distance, how fast should you go, and how can you stay motivated to keep putting in those miles…
First up… How Far Actually Is A Long Run?
The definition of a “long run” changes depending on your fitness level, training experience, and what you’re working toward. There isn’t a magic number that defines it for everyone, but there are some helpful ranges to guide you:
Beginner runners: A long run might be anywhere from 5km to 10km (3–6.2 miles). That’s far enough to build endurance without overdoing it.
Intermediate runners: If you’re already comfortable running a few times a week, your long runs might sit between 12 and 20km (7.5–12.4 miles). This helps you progress toward half-marathon distances and keeps improving your aerobic base.
Marathon training: The longest runs of your training typically range between 25 and 35km (15.5–21.7 miles). These sessions are designed to prepare your body and mind for race day.
As a general rule, your long run should make up 20–30% of your total weekly mileage. This ratio gives your body time to recover while still pushing your endurance limits. For example, if you generally run around 40km per week, your long run might sit around 8–12km.
Physiologically, long runs are where the magic happens. Running for longer periods strengthens your heart, increases capillary density (so more oxygen reaches your muscles), and trains your body to rely on fat as a more efficient fuel source instead of burning through glycogen too quickly. Over time, these adaptations make running at all speeds feel easier, and even your shorter runs will start to feel more effortless.
Why You Need Long Runs In Your Training Schedule
If you’re only ever doing short or high-intensity sessions, you might notice you can sprint fast but run out of puff quickly. Long runs balance that out by building your aerobic endurance — the cardiorespiratory foundation that supports all other types of training.
During a long run, your body learns how to sustain energy output for extended periods. Over time, this improves your running efficiency, meaning you learn to use less energy to maintain the same pace. You also train your mind to stay focused through discomfort, which is a huge advantage on race day.
Think of it this way: long runs aren’t just physical. They teach patience, pacing, and mental discipline. And the more consistently you do them, the more you’ll notice other runs, even intervals or tempo sessions, start to feel easier.
That endurance base doesn’t just help traditional runners either. If you’re training for hybrid or endurance events like HYROX or CrossFit competitions, longer runs help build the cardiovascular stamina needed to maintain performance across the multiple stations and extended time domains. In these settings, your aerobic fitness underpins your ability to recover between high-intensity efforts, allowing you to maintain a steady pace and consistent output from start to finish.
How Can I Pace My Long Runs?
Pacing your long run right is key. Go too fast, and you risk burning out early. Go too slow, and you might miss the training benefit and your goal time. The sweet spot? What running coaches call conversation pace - a speed where you should be able to comfortably talk, but not quite be able to sing along to your playlist.
This usually aligns with Zone 2 heart rate, or roughly 60–75% of your maximum heart rate. At this pace, your body primarily uses fat for energy instead of glycogen, which helps build long-term endurance. Think of this as your “cruise mode”, and don’t make the long run a hard interval by accident.
Here’s how to approach pacing during different phases of your long-run training (your training plan might also show your long runs in this style):
Base building: Keep your pace slower than race pace. The goal is time on your feet, not speed.
Progressive long runs: A practical rule: begin slower than you feel you need (easy pace) and gradually build up in the final few kilometres to finish slightly faster (negative splits). This teaches your body to run strong even when tired.
Tempo fragments. If you’re doing race-specific work, insert short tempo segments at marathon or half-marathon pace to mimic race conditions.
If you’re unsure what pace to aim for, a long run pace calculator can be useful, or simply use the “talk test.” If you can chat comfortably, you’re probably right where you need to be.
For half-marathon or marathon training, keep most long runs slower than your race pace. Use one session a month to include race-pace blocks so you practice the effort, but don’t tax your recovery every week
Best Days To Run Long Distance - Saturday or Sunday?
Ask any runner when they do their long run, and more times than not, the response will be, Sunday. The “Sunday long run” or SLR (slow long run) has become almost sacred in running culture, a ritual that starts your week with purpose (or ends it, depending on how you look at it). Sundays work for most people because you can rest afterwards, and it fits around weekday training or work.
That said, some runners prefer Saturdays, especially if they want to use Sunday as a full recovery day or if Sundays are busy family days. Others might shift their long run midweek if their schedule allows.
What matters most isn’t necessarily when you do it, it’s that you will do it. Pick a day that fits into your week and that you won’t end up cancelling on last minute. It’s not necessary to do a long run every weekend (some Sundays might be an easy 5k), but if you choose a regular day every week that you’re going to run, your body will adapt to that routine, and it’ll start to feel like second nature.
How To Prep For A Long Run
Preparation is everything. A great long run often starts 24 hours before your shoes even hit the pavement. How you sleep, fuel, and plan the day before can make the difference between cruising through your miles and crashing halfway.
Sleep: Aim for at least 7–8 hours the night before. Rest and recovery are crucial because fatigue shows up fast on longer runs.
Fuel the night before: Eat a carbohydrate-rich balanced dinner with protein, and healthy fats; think rice, pasta, potatoes as your base. This helps top up your glycogen stores so you’ve got enough energy to last the distance.
Eat before you run: A small pre-run meal or snack 1–2 hours before sets you up with steady energy. Think oats, toast with nut butter, or a bagel with honey and banana. Avoid anything too high in fat or fibre right before your run, as it can slow digestion and cause discomfort.
Hydrate early: Don’t wait until you’re thirsty. Start hydrating the day before and sip water in the morning. For longer runs (over 90 minutes), consider carrying a hydration vest or planning a route that passes water stops.
Time it right: Avoid stacking your long run straight after a tough strength or interval session. Your legs need to feel fresh to handle the distance and to maintain good form as fatigue sets in.
Route planning: Map your route ahead of time. Knowing where you're going, how far you’re running and what terrain you’ll cover will help you stay focused. Share your route with a friend or family member for safety, or use a tracking app so someone knows where you are.
Gear up: Wear shoes that suit your gait and terrain. Dress for the conditions, functional layers for cooler temps,
moisture-wicking fabrics for heat, and test any new kit on shorter runs first to avoid mid-run surprises.
💡 Editor’s Tip: Treat your long run like a mini event. Lay your kit out the night before, prep your route, and double-check your playlist or podcast queue. It reduces decision fatigue in the morning, leaving more energy for the miles ahead.
How To Recover From A Long Run
Recovery starts the moment you stop running. Refuelling, rehydrating, and resting are all part of the process and just as important as the run itself.
Refuel: Within 30–60 minutes, eat a mix of carbs and protein to restock glycogen and kickstart muscle repair. Think oats with nut butter, a smoothie with banana and protein powder, or a hearty meal that balances both. This window is when your body’s most efficient at absorbing nutrients, so don’t skip it.
Hydrate: You’ll have lost more than just water - electrolytes like sodium and potassium are also depleted through sweat. Rehydrate gradually throughout the day, using electrolyte tablets or coconut water to restore balance and support muscle function.
Stretch and foam roll: Spend 10–15 minutes easing out tight areas like your calves, hamstrings, quads and glutes. Foam rolling helps improve circulation and reduce muscle stiffness, supporting faster recovery and better mobility for your next session.
Soothe sore spots: If your joints or muscles feel tender post-run, try icing them for 10–15 minutes to calm inflammation, especially around your knees, hips, or ankles.
Heat therapy/cold-water therapy: If you’ve got access to a sauna or cold-water therapy, alternating between heat and cold can do wonders. The temperature contrast triggers vasodilation and vasoconstriction, boosting circulation, flushing out metabolic waste, and reducing post-run soreness.
Active recovery: A light walk, slow recovery run, or short yoga session the next day helps stimulate blood flow without adding more stress to your body. It’s one of the best ways to shake off DOMS and keep your training momentum steady.
Rest: Never underestimate a good night’s sleep. It’s during deep sleep that your muscles rebuild, your nervous system resets, and your body adapts to handle longer distances next time. Think of it as the most powerful (and free) recovery tool you have.
💡 Editor’s Tip: Try to schedule your next long run at least 48 hours after a heavy strength session (especially leg-day). It gives your legs enough time to recover so you can go the distance without fatigue holding you back.
How Often Should You Be Doing A Long Run?
Most runners include one long run per week, but it’s not a strict rule. Some coaches recommend following a 10-day cycle, meaning long runs happen every 9–10 days instead of weekly. This can be a great option if you’re training at higher mileage or need more recovery between sessions.
Whatever your schedule, avoid increasing your long-run distance by more than 10% per week. This gradual build-up allows your muscles, joints, and connective tissue to adapt safely and reduces your risk of injury.
Your recovery time will depend on how far and how fast you’ve run. If your long runs are leaving you exhausted for days, scale back the distance or pace until your body adjusts.
The Downsides of Long Runs & How To Avoid Injury
While long runs are essential for endurance, there are some potential downsides if your body isn’t prepared. “Hip and knee pain are the most common issues I see in runners, which is usually linked to muscular weakness and joint instability”, our in-house Sports Therapist, Paddy Longden-Jefferson, tells us.
“Because running is essentially a series of single-leg movements, it puts a lot of stress on your joints. Incorporating targeted strength and conditioning work is key to maintaining stability, improving efficiency, and preventing overload injuries.”
Paddy also explains that he’s noticed an uptick in stress-related injuries, like stress fractures, especially among runners tackling ultra-marathons or multi-day events. These often happen when fueling isn’t enough to match the training load, or when recovery strategies are neglected.
”My advice: progress your training sensibly, follow a structured running program, and include strength and conditioning to build resilience. Prioritising recovery, through sleep, nutrition, and strategies like sports massages, will play a huge role in maintaining performance and keeping runners healthy for the long run”.
Tips to Stay Motivated On Your Long Runs
Let’s be real, some days, you won’t feel like heading out for a 90-minute run. That’s normal. So here are some ways to make it feel easier (and even enjoyable):
Break it up mentally: Instead of thinking “I have 15km to run,” split it into smaller sections; 3 x 5km chunks feels much more manageable.
Find your entertainment: Download podcasts, playlists, or audiobooks to help the miles fly by.
Choose your route wisely: Run somewhere scenic or familiar. A loop you love or a new trail can make all the difference, and even get you excited for your run.
Have a destination: Plan your route so you finish somewhere rewarding - like your favourite coffee shop, brunch spot or home for a hot bath.
Run with someone: Joining a friend or a running club can make your long run feel social and keep your pace steady.
Remember, motivation doesn’t always come before you start. Most of the time, it kicks in because you started.
Long Run FAQs
How should I fuel my long run?
Most people like to refuel with gels every 30-45 minutes on their long runs, meaning for a 15km run, you might take one gel at 5km and another at 10km. Fuelling early can keep your energy stable - for anything longer than 90 minutes, aim for 30–60g of carbs per hour from gels, chews, or sports drinks.
What shoes should I wear for a long run?
Choose a cushioned, supportive shoe that matches your gait and mileage. If you’re training for a race, use the same model you’ll wear on race day so your body can adapt to it.
Can you do a long run with a run club?
You can, but it depends on the club. Most run clubs tend to stick to 5K community runs or occasional track sessions, so a true long run (think anything over an hour) might not always be part of the plan. That said, some larger clubs or marathon training groups do organise longer routes on weekends.
If your local club doesn’t, you could always join their run for the first few miles, then keep going solo to finish your distance. It’s a nice way to get the best of both: the motivation of a group start, and the mental endurance that comes with finishing strong on your own.
Are 10km and 20km considered long distances?
Yes! But ultimately, it does depend on your experience.
If you’re new to running, or regularly run a 5K, 10KM is a major achievement and definitely counts as a long run. For more advanced runners who might be training for a marathon or ultra, 20KM+ is often seen as the average “long run” distance that you’ll complete on your training plan.
What’s the difference between long run pace and marathon pace?
Your marathon pace is typically faster than your long run pace - it’s the speed you aim to maintain or average for 42km. Long run pace, on the other hand, should be slower and more relaxed, usually 60–90 seconds per km slower than your race pace. Here’s how they line up:
Long-run pace: typically slower than marathon pace. It’s about building time-on-feet and aerobic efficiency, and usually falls into zone 2 heart rate zone where you’ll hear people talk about “conversational pace”.
Marathon-pace: this is the pace you want to keep up during race day to achieve your goal time, it can be practised in short blocks during dedicated marathon-pace sessions and will take you to HR zone 3 or 4.
Looking for running-specific training plans or workouts to build unilateral leg strength to improve your running speed, form and efficiency? You can find the workouts you need on our Gymshark Training App, just hit the button below to download!
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