By Orla Walsh, Registered Dietitian & Exercise Physiologist
Key Takeaways
- Carbohydrate timing is essential for performance not just total intake
- Injury risk is driven more by training load and previous injuries than other things
- Poor sleep can increase injury risk by up to 1.8 times
- Most of your running should feel easy if you want to improve
- Sudden increases in training load significantly raise injury risk
- Cross-training can help maintain fitness while reducing impact
- Elite runners follow an 80/20 split of easy to hard training
- Hard sessions should only be done when you’re well-recovered
Introduction
Running is often seen as one of the simplest sports, you just lace up and go. But in reality, there’s a big difference between starting running and progressing in a way that keeps you injury-free and actually improves your fitness. This isn’t something I worried about when I was younger because I didn’t have to. But now that I’m 40y, I need to get things right.
As a registered dietitian and exercise physiologist, I often see people focus on the wrong things early on like pace, distance, or even trying to perfect their running form while overlooking the foundations that truly matter. Now some of this I have learnt through reading papers, other bits from following Premier Physiotherapy on social media and through attending my physio Mike Murphy (rapie.ie).
If you get a few key things right from the beginning, or at least from now, you’ll not only reduce your risk of injury but also make running feel far more enjoyable and sustainable.
Here are eight things I encourage everyone to get right before they start running, or when they’re failing to progress.
1. Get Your Carbohydrate Timing Right
When it comes to running performance, it’s not just about how many carbohydrates you eat across the day it’s about when you eat them.
A brilliant researcher called Louise Burke has done great research highlighting the importance of carbohydrate availability and how it plays a key role in determining the quality of training sessions and long-run performance. In other words, even if your overall intake is adequate, poorly timed carbohydrates can still leave you under-fuelled when it matters most.
This is particularly important for:
- Long runs
- Interval or higher intensity sessions
- Races or events
If your carbohydrate stores are low going into these sessions, you’re more likely to:
- Fatigue quicker
- Struggle to hit target paces
- Get less training adaptation from the session
- Therefore impacting precevied effort, progression and performance!
In practice, this means:
- Eating a carbohydrate-containing meal 2–4 hours before key sessions
- Including a small snack closer to the run (30g of carbs in the hour before)
- Refuelling with carbs quickly afterwards to support recovery and the performance of your next run.
The key takeaway here is simple:
Carbohydrate timing isn’t just optimal it’s essential if you want to train well and feel good doing it.
2. Don’t Over-Fixate on Running Form
It’s very easy to fall into the trap of thinking you need to “fix” your running form before you even get started. Social media doesn’t help here, there’s no shortage of advice on cadence, foot strike, and posture. I fell into this trap!
But the evidence tells a different story. And, my phsio Mike was really clear about this. Orla – be patient.
A 2024 paper found that biomechanical factors have weak and inconsistent associations with injury risk. What actually matters more?
- Your training load (how much youre doing, so think heart rate and time spent running)
- Your previous injury history
That’s not to say form doesn’t matter at all but it’s often overemphasised, especially for beginners.
What I recommend instead:
- Focus on gradual progression in training
- Avoid sudden spikes in how long you run for or the pace at which you run
- Pay attention to how your body feels rather than chasing “perfect” technique
The takeaway:
You’re far more likely to get injured from doing too much too soon than from having imperfect running form.
3. Sleep Is a Performance Tool (Not a Luxury)
Sleep is one of the most underrated factors in both performance and injury prevention.
Research shows that runners with poor or inconsistent sleep patterns have up to a 1.8 times higher risk of injury. That’s a significant increase and one that’s often overlooked. It also makes sense as I’ve had more injuries since having kids, which is in part down to night time wakings.
Sleep impacts:
- Recovery between sessions
- Hormonal balance
- Muscle repair
- Energy levels and motivation
- What we eat
- Our concentration when running (hello pothole!)
And importantly, it’s not just about total hours it’s also about consistency (waking at the same ish time every day, and going to bed at the same ish time every evening).
If your sleep is irregular or disrupted, your body is less able to cope with training stress, even if your programme looks “reasonable” on paper.
Simple ways to improve sleep:
- Keep a consistent bedtime and wake time
- Limit screen exposure before bed
- Avoid late caffeine (bed time minus 13 hours).
- Prioritise wind-down time in the evening (avoid phone use after dinner).
The takeaway:
If your sleep is poor, your injury risk increases even if everything else looks right.
4. Most of Your Running Should Feel Easy
One of the biggest mistakes I see especially in beginners is running every session at a moderate or hard effort. It feels productive in the moment, but it’s not how you build long-term fitness. I’ve worked with elite athletes and they’re so good at moniroting this. Those that train like athletes but work 9 to 5, not so much.
Research consistently shows that a polarised training approach where most training is done at a low intensity, with a smaller proportion at higher intensity leads to the greatest improvements in VO₂ max and overall performance. This is in part through with the fact that you’ll be more consistent with training because you’ll be sick and injured less often.
In simple terms:
- Most runs should feel comfortable and somewhat conversational
- A smaller number of sessions should be challenging and structured.
When you run too hard, too often:
- You accumulate fatigue quickly
- Recovery is compromised
- Injury risk increases
Easy running might feel “too easy”, but it plays a critical role in:
- Building your aerobic base
- Supporting recovery
- Allowing consistency week to week
The takeaway:
You can’t maximise performance by running hard all the time. Most of your running should feel easy.
5. Build Gradually: Patience Beats Progression Hacks
If there’s one principle that underpins injury prevention in runners, it’s this: progress gradually.
A big review of the literature found that large increases in weekly training volume or intensity are associated with a higher risk of injury.
This is where many runners go wrong. Motivation is high at the start, and it’s tempting to:
- Increase distance too quickly
- Add extra sessions
- Push pace before your body is ready
But your muscles, tendons, and joints need time to adapt to the impact of running.
A more effective approach:
- Increase total weekly volume gradually
- Avoid big jumps in either distance or intensity
- Keep changes small and consistent week to week
A simple rule of thumb is to think in terms of steady progression rather than sudden leaps.
The takeaway:
Injury risk increases when you jump volume or intensity too quickly. Patience always wins.
6. Cross-Training Can Protect Your Progress
Running is a high-impact activity, and sometimes your body needs a break from that impact even if your fitness is improving. The good news is that reducing running doesn’t necessarily mean losing fitness.
One study found that runners who switched entirely to elliptical training for three weeks maintained almost all of their VO₂ max. That’s a powerful reminder that cardiovascular fitness can be preserved without constant pounding on the pavement. For me, that means bringing in more swimming and cycling.
Mixing up your training is particularly useful when:
- You’re feeling niggles or early signs of injury
- Your calves, knees, or joints are under strain
- You need to temporarily reduce running load
- You want to keep things interesting
Effective options include:
- Elliptical training
- Cycling
- Swimming
These allow you to:
- Maintain aerobic fitness
- Reduce impact stress
- Stay consistent while recovering
The takeaway:
Cross-training is not a step backwards. It’ can be a smart way to maintain fitness while managing load.
7. Follow the 80/20 Rule
If you look at how elite endurance athletes train, there’s a very clear pattern: they spend most of their time training at a low intensity.
This has been researched before in endurance sports and they found that athletes complete roughly:
- 80% of their sessions at low intensity
- 20% at moderate to high intensity
This aligns closely with the idea of polarised training, but it gives you a more practical framework to follow.
What does this look like in real life?
If you’re running 3-4 times per week:
- 2-3 runs should feel easy and controlled
- 1 session might be intervals, hills, or tempo work
Where people go wrong is drifting into the middle—running too hard for easy days, but not structured enough on harder days.
The takeaway:
The biggest gains in endurance come from a large volume of easy running, not constant high effort.
8. Be Strategic With Hard Sessions
Hard sessions like intervals, tempo runs, or hill work are incredibly effective, but only when used at the right time.
What matters just as much as the session itself is the condition you’re in when you do it.
If you go into a hard session:
- Underslept
- Underfuelled
- Dehydrated
- Or carrying fatigue
You’re more likely to:
- Perform poorly
- Get less training adaptation
- Increase your risk of injury
On the other hand, when you’re well-recovered:
- You can hit the right intensity
- You get a stronger fitness response (including improvements in VO₂ max)
- Your body is better able to tolerate the load
So rather than forcing hard sessions into your week, it’s better to earn them through good recovery habits.
Before a harder run, ask yourself:
- Did I sleep well?
- Am I properly fuelled?
- Do I feel recovered?
If the answer is no, it’s often smarter to adjust the session.
The takeaway:
Hard sessions are most effective—and safest—when your body is ready for them.
Putting It All Together
When you step back, these eight principles all connect.
Good running isn’t about pushing harder it’s about getting the fundamentals right consistently:
- Fuel properly, especially around key sessions
- Prioritise sleep and recovery
- Keep most runs easy
- Progress gradually
- Mix up your cardio when needed
- Be selective with intensity
Frequently Asked Questions
1. What should I eat before running in the morning?
If you’re running first thing, a small carbohydrate-based snack like toast with jam can help improve energy levels. If you’re waking up to head out the door, 300ml of fruit juice may be better as it’s digested quicker than food. For longer or harder sessions, having a more substantial meal beforehand (if time allows) will better support performance.
2. How much sleep do runners need?
Most adults need between 7–9 hours per night, but consistency is just as important as duration. Irregular sleep patterns can negatively impact recovery and increase injury risk.
3. Is running every day bad for beginners?
For most beginners, running every day isn’t necessary and can increase injury risk. Including rest days or cross-training allows your body to adapt more effectively.
4. How quickly should I increase my running distance?
Progress should be gradual. Sudden increases in distance or intensity are linked to higher injury risk, so aim for steady, manageable increases over time.
5. What is the 80/20 rule in running?
It refers to doing about 80% of your training at a low intensity and 20% at moderate to high intensity. This approach is commonly used by elite endurance athletes.
6. Can I improve fitness without running every session?
Yes. Cross-training methods like cycling or using an elliptical can maintain cardiovascular fitness while reducing impact on the body.
7. Do I need to fix my running form before I start?
Not necessarily. While form can play a role, research suggests that training load and previous injuries are more important factors in injury risk.
8. Why do I feel tired on every run?
You may be running too hard too often, under-fuelling, or not recovering properly. Slowing down and improving sleep and nutrition can make a big difference.
9. Are hard sessions necessary for beginners?
They can be beneficial, but only when introduced appropriately and when you’re well-recovered. Most of your training should still be easy.
10. How do I avoid injury when starting running?
Focus on gradual progression, prioritise sleep, fuel properly, keep most runs easy, and avoid sudden spikes in training load.
