By Clinton Grobbelaar, Physiotherapist. Published 13 October 2026.
Most Surrey Half Marathon injuries are overuse injuries, not accidents. Shin splints, Achilles and calf pain, runner's knee and outer-knee pain account for the bulk of what we treat in the build-up, and nearly all of them come from adding distance too quickly. Build your mileage by about 10% a week and most never start.
In short
- The next Surrey Half Marathon is on Sunday 21 March 2027, so a sensible build starts now rather than in January.
- Four injuries cause most of the damage: shin splints, Achilles pain, runner's knee and outer-knee pain.
- The 10% rule is the single best piece of prevention: add no more than 10% to your weekly distance.
- Strength work twice or three times a week does more for your race than extra junk miles.
What is the Surrey Half Marathon?
The Surrey Half Marathon is a closed-road race held each March, alongside a 5k and a junior race. The 2027 event is set for 21 March.
That makes it a winter training block. You will be building through dark evenings, cold calves and wet pavements, which is exactly when injuries cluster.
The useful news is that the main half marathon injuries are predictable, which makes them preventable.
Which injuries does Surrey Half Marathon training cause most?
Four problems account for most of the running injuries Brookwood Physio sees in a race build-up.
| Injury | Where it hurts | Usual trigger |
|---|---|---|
| Shin splints (medial tibial stress syndrome) | Along the inside edge of the shin bone | Jumping up in mileage, hard surfaces |
| Achilles pain (Achilles tendinopathy) | The cord above the heel, often stiff first thing | Hill reps, speed work, tight or weak calves |
| Runner's knee (patellofemoral pain) | Around or behind the kneecap | Long-run volume, weak hips and glutes |
| Outer-knee pain (iliotibial band syndrome) | Outside of the knee, comes on at a set distance | Sudden long runs, camber and downhill |
Shin splints are the one most runners meet first. The NHS describes them plainly: shin splints happen when you have put too much stress on your leg, and they usually get better within a few weeks.
Achilles pain is the one that costs the most time. Guy's and St Thomas' NHS Foundation Trust states that most people need six to nine months of rehabilitation before returning to full activities without pain.
That six to nine month figure is the reason not to run through Achilles pain in a 20-week training block.
When in a training block do runners break down?
Two points, in our experience, do the damage.
The first is the third or fourth week. That is when the early enthusiasm has you running more often, further, and faster all at once.
The second is the step up to double-digit long runs. The jump from eight miles to twelve is where shin and knee pain arrive.
Injuries follow changes in load, not total load. A runner comfortably covering 25 miles a week is usually safer than one who did 10 last week and 18 this week.
Newer runners carry the most risk. A 2015 systematic review in the journal Sports Medicine found 17.8 injuries per 1,000 hours of running among novice runners, against 7.7 among recreational runners.
Niggle or injury? What you can train through
Not every ache needs a rest week. The honest test is what the pain does, not how much it hurts.
| Probably a niggle | Probably an injury |
|---|---|
| Eases within the first ten minutes of a run | Gets worse the further you go |
| Gone the next morning | Still there, or worse, the next morning |
| Both legs, or moves around | One spot you can put a finger on |
| No limp, no swelling | Changes how you run, or swells |
Some symptoms are not a judgement call at all. The runners' guidance from Newcastle Hospitals NHS Foundation Trust says to seek medical advice after a fall or trauma, if pain is constant even at rest, if there is significant swelling or bruising, or if you cannot put weight through the leg.
Bone pain that worsens run by run and hurts when you press one small spot on the shin needs assessing before your next session, not after it.
How do you stop these injuries before they start?
Four habits prevent the great majority of what we treat.
- Follow the 10% rule. The same NHS trust advises increasing the distance you run by 10% each week, and notes that free running programmes often run over 12 weeks.
- Change one thing at a time. More distance, more speed, or more frequency. Pick one per week, not all three.
- Strength train two or three times a week. The same NHS guidance recommends three sets of 3 to 10 repetitions for most exercises.
- Keep an easy run easy. If every run is a bit hard, nothing recovers and the next hard session starts from a deficit.
Strength work is the part runners skip and the part that protects knees, shins and tendons most.
A short strength routine for half marathon training
This takes about 15 minutes and needs no equipment. Done two or three times a week, it covers the weaknesses behind most running injuries.
- Calf raises. Both legs first, then single leg as you improve. Slow down on the way back.
- Single-leg bridges. For glutes, which take the load off the knee.
- Step-downs. Control the descent off a low step. This is the one runner's knee hates.
- Side-lying hip raises. For the outer hip, which keeps the knee tracking straight.
- Forward plank. The Newcastle NHS guidance suggests holding 15 to 60 seconds, repeated two or three times.
Add repetitions before adding difficulty, and stop any exercise that hurts sharply.
Want it built around your own legs instead of a generic list? That is what exercise prescription at Brookwood Physio is for.
Clinton has worked with runners for over 30 years. What suits a first-timer is not what suits a club runner chasing 90 minutes.
What about taper week and race day?
The taper is not the time to fix anything. It is the time to arrive fresh.
Cut your distance in the final two weeks but keep some pace in your legs.
Resist the urge to book a deep sports massage two days before the race. New treatment that close is a gamble with nothing to win.
If you like a massage in a training block, have it in an easy week. The difference between sports massage and physiotherapy matters here: one maintains, the other fixes.
Nothing you do in the final ten days will make you fitter, but plenty of it can make you slower.
When should you see a physiotherapist?
Get assessed if pain has been there for more than a week of running, if it is changing your gait, or if it has stopped you completing a planned session twice.
Go earlier than that for Achilles pain. The Guy's and St Thomas' guidance notes that strengthening the tendon helps it heal, but that overloading it can make pain worse, so the dose matters.
Go to urgent care instead if you cannot weight-bear, or the leg is badly swollen.
The earlier a running injury is assessed, the more likely it is that you make the start line.
Where the evidence is mixed, we say so. Shockwave therapy has a real place in stubborn Achilles cases, but the Guy's and St Thomas' guidance puts it after six to nine months of a proper exercise programme, not instead of one.
Frequently asked questions
Twelve weeks is a common structure, and Newcastle Hospitals NHS Foundation Trust notes that free running programmes often run over 12 weeks. If you are starting from very little running, give yourself 16 to 20 weeks.
You might finish, but the injury risk is high and the recovery is long. The problem is not the distance on the day, it is the mismatch between what your tendons and bones are used to and what you ask of them.
Stop the exercise that caused them, which is the NHS advice, and switch to gentle alternatives such as swimming or cycling while they settle. Shin splints usually improve within a few weeks, then you rebuild slowly.
Three to four runs a week suits most people preparing for a half marathon, with strength work on two or three of the other days. Adding a fifth run is usually less useful than making the existing four better.
Yes, and you should. Strength work two or three times a week is recommended in the Newcastle Hospitals NHS runners' guidance, and it protects the joints and tendons that running loads hardest.
Three weeks out at the latest for anything that needs treating, which leaves room to adjust your training. Inside the final week, treatment should be light maintenance rather than anything new.
Make the start line
If something is nagging in your build-up to March, it is easier to deal with in October than in February. Brookwood Physio runs hour-long, fully hands-on sessions in Brookwood, Woking, and sees everyone from first-time half marathoners to club runners.
You can book an assessment whenever it suits you.
Contact us