Building muscle while training for a marathon involves two competing goals. It’s not impossible, but focusing on both inevitably compromises performance. So, in preparation for the TCS London Marathon, I put my weightlifting goals on hold at the start of 2026 to give the best account of my running self.

With ambitions of a PB, I still didn’t want to lose everything I’d built in the gym. That meant shifting into a muscle-maintenance phase. Gym time was swapped for more miles on the road, making the sessions I did keep even more important – here’s how I managed it.

During the peak weeks of marathon training, I was running close to 50 miles, with plenty more weeks above 40. That’s still below what faster marathoners might hit, but my priorities were different – above all, I wanted to reach the start line in Blackheath injury-free.

To make that happen, I reduced my weekly strength training volume while keeping intensity high. This isn’t new. As I’ve leaned further into running over the past few years, my lifting has gradually dropped from six days a week to five, then four, and eventually three during this marathon block.

Research shows that while higher volume is more effective for building muscle, intensity can be just as effective for maintaining it. Bodybuilding legend Dorian Yates is a well-known advocate of this approach – training to maximum effort in minimal time, often referred to as the minimum effective dose.

My week looked like this: a heavy legs session on Monday (low reps, heavy weights), an upper-body session on Tuesday following the same structure, and a full-body workout on Friday using lighter weights and higher reps to build muscular endurance. Each session lasted no more than an hour.

With less overall volume, compound movements became essential – both for efficiency and maintaining strength. Back squats, Romanian deadlifts, bench press, bent-over rows, and pull-ups formed the backbone of my training, with running-specific and core work added in.

It worked. Strength held steady across key lifts – including a 100kg back squat and 80kg bench press – and there were no noticeable changes in muscle size.

Maintaining muscle isn’t just about what happens in the gym – nutrition plays a huge role. Running five times a week places a significant demand on the body, requiring enough fuel to support both performance and recovery. Joints take a hit, muscles are constantly taxed, and cognitive function can dip with high mileage.

That’s where a high-protein, high-calorie diet proved essential.

Not only did it help prevent under-fuelling – and the risk of RED-S (Relative Energy Deficiency in Sport) – it also ensured my body didn’t become catabolic, where muscle is broken down to meet energy demands. ESN’s protein bars and powders helped me hit a daily target of around 160g of protein, roughly double my bodyweight in grams. Calorie intake was adjusted depending on the day’s training load.

By race day, the work was done. In the final weeks, I tapered off strength training to avoid placing unnecessary stress on my body. Research published in the Scandinavian Journal of Medicine & Science in Sports suggests that even a 10-week break from training doesn’t significantly impact long-term strength or muscle retention – so I knew anything lost would come back quickly.

Carbohydrates were key in the lead-up and on the day itself, helping fuel the effort alongside the New Balance FuelCell SuperComp Elite v5 on my feet.

I achieved what I set out to do: run a PB, enjoy the experience and maintain muscle mass.

As major sporting events go, the 2026 TCS London Marathon will likely go down as one of the most memorable. Not only did two men – Sebastian Sawe and Yomif Kejelcha – officially break the two-hour barrier, but Tigst Assefa set another women’s world record. Add in 37 Guinness World Records, a record number of finishers and millions raised for charity, and it was a landmark race.

Ryan is a Senior Writer at Men’s Health UK with a passion for storytelling, health and fitness. Having graduated from Cardiff University in 2020, and later obtaining his NCTJ qualification, Ryan started his career as a Trainee News Writer for sports titles Golf Monthly, Cycling Weekly and Rugby World before progressing to Staff Writer and subsequently Senior Writer with football magazine FourFourTwo.

During his two-and-a-half years there he wrote news stories for the website and features for the magazine, while he also interviewed names such as Les Ferdinand, Ally McCoist, Jamie Redknapp and Antonio Rudiger, among many others. His standout memory, though, came when getting the opportunity to speak to then-Plymouth Argyle manager Steven Schumacher as the club won League One in 2023.

Having grown up a keen footballer and playing for his boyhood side until the age of 16, Ryan got the opportunity to represent Northern Ireland national futsal team eight times, scoring three goals against England, Scotland and Gibraltar. Now past his peak, Ryan prefers to mix weightlifting with running – he achieved a marathon PB of 3:31:49 at Manchester in April 2025, but credits the heat for failing to get below the coveted 3:30 mark…

You can follow Ryan on Instagram @ryan.dabbs or on X @ryandabbs_