How I rebuilt my muscle and strength in 6 weeks with weightlifting and a high protein diet

• Liam Cavanagh set himself the 2023 goal of rebuilding his strength after a training break.
• Consistency in the gym and tracking his nutrition helped him smash his targets in six weeks.
• Cavanagh aims to eat at least 3,500 calories and 200 grams of protein daily.

Liam Cavanagh is a qualified personal trainer, but he still makes new year fitness goals like the rest of us.

He lost strength last year after training for a marathon and traveling, and his resolution was to get back to and exceed the weight he was lifting at the end of summer 2022. 

Cavanagh shared his new year training journey with Insider. He said working out five times a week was a "non-negotiable" and that he'd be tracking his food intake.

As an experienced gym-goer, he knew progress might be slower and would require a certain level of discipline, so he vowed to push himself hard in the gym, sticking with the body-part split format (training a different body-part every day) that he enjoyed.

It paid off: After six weeks, Cavanagh had not only hit his previous levels of strength but surpassed them. 

Cavanagh started working out as a teen because he didn't want to be skinny

Cavanagh, 25, started working out aged 15 because he "didn't want to be the skinniest person" at house parties, he said.

He didn't make much progress at the gym for the first three years because he didn't know what he was doing, he said. But he learned the importance of eating for building muscle at college and fell in love with working out and the benefits he felt, such as having more energy and being more disciplined in other areas of his life.

He qualified as a personal trainer in September 2019 and stayed active during the UK's COVID lockdowns, but found working out five times a week challenging when life returned to normal.

After a good start to 2022, factors like being away, social events, and training for the London Marathon in October got in the way of Cavanagh's workout consistency and meant running replaced gym time.

Getting back to the gym felt good

Cavanagh's main strength goals in 2023 were centered around the three big lifts: squats, deadlifts, and bench presses.

In 2022, his personal bests were:

• Squats: 110 kilograms (243 pounds) for three sets of seven
• Deadlifts: 140 kilograms (287 pounds) for three sets of six
• Bench press: 90 kilograms (198 pounds) for three sets of six

In his first workouts of 2023, Cavanagh did: 

• Squats: 90 kg (198 pounds) for three sets of 10
• Deadlifts: 120 kilograms (265 pounds) for three sets of eight
• Bench press: 80 kilograms (176 pounds) for three sets of eight

Getting back to the gym felt surprisingly good, Cavanagh said, and he didn't feel like he'd regressed too much on most exercises.

He was hitting his five workouts a week every week, working out Monday to Friday so he had the weekends for socializing and relaxing, and consistency was easier when going to the gym was part of his morning routine.

Cavanagh also did Dry January, which he said definitely helped as he felt energized and was sleeping well.

Mid-way through January, he started eating more

Cavanagh didn't change his diet at first to see how his weight and strength might change while eating around his maintenance calories. Not only did Cavanagh not gain weight, he actually dropped a small amount.

After a couple of weeks, he started eating in a calorie surplus to aid muscle-growth, tracking his calories and protein to ensure he was eating enough. He aims for at least 3,500 calories and 200 grams of protein daily on average, spread across the week so he doesn't worry about each day being perfect.

As a numbers person, and someone who had experience tracking his food intake, Cavanagh said he enjoys the process and finds it satisfying to hit his targets.

And the combination of consistent, challenging strength-training and a high-protein diet with a calorie surplus was working — Cavanagh's weight started to slowly increase and he began to notice more muscle growth.

"I'm definitely a lot more vascular so maybe I've lost a bit of body fat," Cavanagh said.

As January went on, the numbers in the gym were creeping back up to where they had been too, and Cavanagh was feeling great.

Three weeks into the month, Cavanagh checked his workout tracking app and realized it was the first time he'd done five workouts a week for three consecutive weeks since November 2021. He felt extra motivated to continue his consistency, he said.

By mid-February, he had smashed his strength targets

Six weeks into 2023, Cavanagh's consistency with training and nutrition had paid off as he had surpassed his strength goals.

He felt both leaner and stronger and he was lifting more than he had done the previous summer and achieved:

• Squats: 110 kilograms (243 pounds) for three sets of eight
• Deadlifts: 140 kilograms (287 pounds) for three sets of eight
• Bench press: 95 kilograms (209 pounds) for three sets of eight

Cavanagh plans to continue eating in a small calorie surplus and training hard to keep up his strength and muscle-building progress, without gaining fat.

At the start of the year, he weighed 87.5 kilograms (193 pounds), and after six weeks he was 89.9 kilograms (198 pounds), he said.

Not only was Cavanagh stronger and leaner than he was at the start of 2023, he had fallen back in love with training consistently, he said.

"I've really enjoyed the process," he said. "It makes a massive difference having that goal in mind and being very conscious in the gym, pushing myself."

Cavanagh is enjoying nailing his nutrition and workouts, is "buzzing" to see his strength increase, and it feels sustainable so he very much plans to continue.

"It gives you such a good feeling," he said. "I come away from the gym so pumped."