Return to running after a broken foot is slower than I expected. Three months on, I am running again, and I am grateful for that. My fitness is not where it was.

Today is Day 2083 of my daily running streak. I have covered 16,059.56km towards a lap of the world, which is 40,075km. That leaves 24,015.44km. I run in barefoot-style footwear and vlog every run. The aim is to raise £1M for children's causes, including Great Ormond Street and BBC Children in Need. The streak is the method, so I protect it.

What happened on the run

Before the injury, my standard run was about 16,059.56km. Now I am running 6 to 16,059.56km. My pace has come back close to where it used to be. My cardiovascular fitness has not.

Two things show it. Filming while running is harder on my lungs than it was before the break. And my heart rate sits up to 10 beats per minute higher than it did at the same effort before the injury. Same pace, same route, a harder body response.

Tonight I was four kilometres into a 6km run and grinding. I was tired and felt faint, so I slowed to a walk. I was also travelling, and it was around half past midnight, so I was running back to back with a long day behind me. Pushing through would have risked the streak more than walking did. I took the breather.

Why recovery from injury takes longer than the bone

I broke my foot about three months ago. Bone healing and fitness recovery run on different clocks. The foot can be cleared to run while the engine behind it has been detuned for weeks.

Through the injury I kept the streak alive with power walking and run-walk intervals. That kept me moving every day. It did not keep my cardiovascular fitness where it was. Walking is not a substitute for the load of running, and I should be honest about that.

How long does it take to get back to full fitness?

Nobody can give you a single number. It depends on your age, your starting fitness, how much you train and how much time you can give to recovery. I am not going to pretend to offer a formula.

What I can offer is a rule I am trying to apply to myself. Whatever time you think it will take, multiply it by three. I am three months post-injury, and my gut feel is that it will take the best part of another three months to get back to where I was. I may be wrong. I would be glad to be.

The marathon question

I had two marathons planned this spring. The first is about three months away and the second about four. Right now I do not think I could finish a marathon, let alone aim for a time.

I have not cancelled anything. I am using two checks instead of a hope:

1. I will track heart rate against pace. If the same pace costs fewer beats over the coming weeks, my fitness is returning. If it does not, I will have my answer. 2. I will add longer runs during the build-up, to find out whether my legs can still handle the distance.

If the data says no, I will not enter. A marathon I am not ready for is a bigger risk to a 16.5-year streak than a marathon I miss.

The lesson for me

Frustration is useful only if it changes what I do next. Looking at my heart rate and feeling a long way from full fitness was uncomfortable. The practical response is to measure it, not argue with it.

I also had to accept that consistency does not mean intensity. The streak does not need a 16,059.56km run every day. It needs a run, or a walk on the hard days, every day. Scaling back to 6km on a faint night is part of that.

The mission anchor

The target is 40,075km and £1M for children's causes. At roughly 10km a day, the mission runs for years, and an injury is one section of it, not the whole thing. The children I run for will still be here when my heart rate settles. Showing up at reduced distance is better than skipping to wait for a better version of me.

If you are recovering from an injury

If you exercise regularly and you are on the road back, here is what I would pass on:

1. Expect the fitness drop to be bigger than the physical injury suggests. 2. Use heart rate against pace to measure progress, not how the run feels. 3. Multiply your estimate of the recovery time by three. 4. Test your legs with longer runs before you commit to a race. 5. Walk when you need to. It is a decision, not a failure.

If this is useful, watch the full episode, and tell me in the comments how long your own recovery took. I reply to everyone. If you believe in the mission, subscribing, sharing and commenting helps more people see the vlog, and more people seeing it helps the fundraising.

I will be out again tomorrow.

Watch the full episode: https://youtu.be/RSJzP8K-B8U