Inside Eilish McColgan's Training for the Half Marathon

Eilish McColgan knows what it takes to perform at the highest level. As a Commonwealth champion and Olympian, she’s spent years refining her training with the long view in mind. Now preparing for the Great North Run, Eilish continues to build her fitness with the same patience and intent that have defined her career.

Her preparation for GNR doesn't add any dramatic changes, it’s a smart progression. After running the London Marathon in April, she’s using the summer as an abbreviated build back towards a peak. “Training doesn't really change too much as I'm building up my fitness after taking some time off after London Marathon,” she explains. “The only thing we will do is start to elongate my long runs, add in some longer tempo efforts, and essentially just increase my overall volume a little to try build some strength for the half distance.”

Eilish McColgan’s Approach to Sustainable Performance

Eilish’s training is built around balance. Each week includes two interval sessions on the track, one long run, several easy runs, and one full rest day. It’s a rhythm that allows her to build toward race day without sacrificing recovery or increasing injury risk.

She doesn't run as many miles as some other elite endurance athletes. Instead, she adds volume through low-impact cross-training sessions. “I cross train a few days a week in the evening instead of double running,” she says. “It's not something I periodise as I've found it a real useful key to staying injury free.”

Strength work is another non-negotiable. Eilish lifts twice a week year-round, only reducing weights slightly during taper periods. She keeps her hard efforts focused and limited: “I only ever have two hard intervals a week - regardless of what event I'm training for or what time of year it is.”

Tracking Progress with Data

Eilish uses the COROS Training Hub to track performance trends and monitor progress.

After a strong build to her debut marathon in April and a brief recovery period, Eilish has rebuilt her Base Fitness over the last few months, already matching her peak of 160 from April. Despite the time off and shortened training block, Eilish is still able to lean on years of training & aerobic base-building to reach peak performance.

During her most recent build, Eilish has spent time in all six heart rate zones, but has slightly stronger emphasis on Zone 2 (Aerobic Endurance) and Zone 4 (Threshold).

A Shortened Build

Because she raced the London Marathon in April, Eilish didn’t follow a traditional multi-phase training cycle for the GNR. “This year is a little different… I've just had to build back into my normal schedule and bring in some faster 10K type sessions because my speed hasn't been a priority.”

She describes the summer in three distinct blocks: “June has been just a 'get into running again' month, July a 'get fit camp' and August preparing to race.” That means the usual base and race-specific phases have been compressed, but the core training elements remain.

“One long run, two harder interval sessions on the track and the rest of my days are just easy runs. A few days a week, I'll cross-train in the evening for 40-60mins. The cross-train is very easy and within a low HR zone to ensure I'm recovering between the hard days.”

For her intense sessions on the track, Eilish says she likes to keep it simple. "Things like 10x1000m or 20x400m are staple sessions within my schedule."

Tapering to Peak

As the race approaches, Eilish stays disciplined. “Typically for a Half Marathon, I'll have my last hard session around a week out and then everything in the final week will be easy or super controlled.”

That final week includes a rest day two days before the race and only a short warm-up on the day before. “It's super light before racing,” she says. “You cannot get any fitter in the final week and can only take away from your performance!”

Her COROS recovery metrics help her validate those decisions, confirming that her body is ready to absorb training and peak on race day.

Eilish maintains strong recovery throughout all phases of her training. Her HRV rarely drops below the recommended zone, regardless of whether she is in an intense training block or tapering for a race. The spikes? Those often align with the day following her off-days, showing the results of her strong and consistent recovery habits.

Advice for All Runners

For those tackling the Great North Run for the first time, Eilish offers a reminder:

“Don't be afraid to taper down that final 7–10 days. You won't get any fitter, but you might detract from your performance on race day. It's better to feel fresh and give your legs the chance to perform!”

Once you've arrived at the start of your race, that's when it all comes together.

“All the hard work is done so believe in it. And more importantly, soak up all the atmosphere on race day. It's a fantastic event with people cheering from start to finish so use the energy towards your new PB!”