Get Fit for Life

How regular exercise affects cellular change

Doctors have known since the 1980s that exercise is possibly the most e ective thing we can do to stay healthy. “If exercise could be packed into a pill,” as Dr Robert Butler famously said, “it would be the single most widely prescribed and bene cial medicine in the nation.”

A regular training programme – embedded as part of your lifestyle – can keep heart disease at bay; help to prevent cancer; reduce the risk of diabetes; improve mental health; keep your mind sharp; and even extend your lifespan, full stop. But now, new research is showing that decades-long training also helps certain genes in our makeup ‘express’ or ‘turn on’, giving an enduring edge in the health stakes. Here’s how you can take advantage of that science…

THE LONG GAME

A 2020 study, published in Cell Reports, looked at the e ect that regular exercise, over a period of decades, has on our genes. It discovered that certain genes, which play a role in your metabolic pathways, were responsive to endurance training. is type of training signi cantly changed the activity of more than 1,000 genes in their study subjects, when compared to controls. “Although short bouts of exercise have been shown to in uence the gene activity in our muscles,” says study author and assistant professor Mark Chapman, “it is the dedication to habitual exercise over a lifetime that is associated with long-term health bene ts.” e net e ect of these changes is to increase the e ciency of those energy pathways, making you tter, while regulating your metabolism and guarding against diseases such as diabetes. In case you’re worrying that you’ve missed the boat, the good news is that you don’t need to have been exercising for decades to begin to bene t. In fact, after a single month, individuals with impaired metabolisms shifted their gene activity enough after committing to a regular endurancetraining programme to achieve similar physiological adaptations to the long-term training groups. “is suggests that even short training programmes of six to 12 months are enough to positively in uence the health of people su ering from metabolic disorders,” says author Carl Johan Sundberg, physiology professor at the Karolinska Institute.

If you needed another reason to start, or stick, with a new exercise routine, a permanently healthier metabolism – that will make your immune system more resilient to disease, improve your tness, and allow you to maintain consistent energy levels – is a pretty solid one.

“Decadeslong training can give you an enduring edge in the health stakes”

“HIIT can ‘activate’ your genes, which makes the energy in your cells more readily available during tough workouts”

HIIT THOSE HIGHS

While the Cell Reports study found that aerobic endurance training, such as running or cycling, changed the activity of 1,000 genes (compared to 26 for anaerobic training), the scientists said that this may be down to muscle gene activity being related to proteins, rather than the RNA

– the molecule that codes and decodes genes – that they studied.

is idea is involved in a 2018 study into high-intensity interval training (HIIT), which looked at how gene expression is important to muscle adaptation after supra-maximal HIIT sessions (which rely on the anaerobic energy system).

By taking a sample from the muscles themselves, the study discovered that HIIT ‘activated’ genes, which increased the weight of the energy units within the cells that make up these muscles (called mitochondria). is process also happens as a response to aerobic endurance training.

So, if you love anaerobic HIIT sessions, but aren’t so fond of steady-state cardio workouts, here’s another way to permanently increase the amount of glucose your muscles can store, making this energy immediately available to fuel tough workouts.

Another bonus of HIIT, resistance training and endurance training, according to the study authors, is that they all enhance the expression of genes that relate to the network of proteins in the extracellular matrix (ECM), which is a component of all your body’s tissues.

is sounds complicated, but the net e ect is that your muscle bres are cushioned from mechanical strain when you work out, and they are healthier because the ECM is remodelled by exercise. (An unhealthy or abnormal ECM can lead to serious conditions, including cancer.)

RESISTANCE RECODED

Strength training has also been shown to reprogramme certain genetic features – speci cally, leukocyte DNA – according to a 2016 study published in the European Journal of Applied Physiology.

Resistance training can increase mitochondrial capacity, which may prevent muscle loss

After looking at men doing eight weeks of three resistance workouts per week, the study team found that as well as the expected increase in muscular strength, various genes also had increased expression. ese included those involved in developmental protein and the release of human growth hormone.

Another bonus e ect of building stronger, leaner muscle is that doing these workouts consistently has been linked with not just stalling, but reversing the ageing process. Once you hit 30, you’re in the zone of naturally losing muscle as you age – as much as three to ve per cent per decade – unless you take additional steps, through resistance training, to maintain the muscles that you have.

Studies already show that resistance training in older adults can increase mitochondrial capacity (those cell energy units). More research is needed, but scientists believe that may prevent muscle loss. A 2007 study, from Simon Melov and Mark A. Tarnoplosky, compared older and younger people doing resistance exercise training. At the beginning of the study, the older people were 59 per cent weaker than the younger, but after six months of resistance exercise they were only 38 per cent weaker. What’s more, they found that 596 genes were expressed di erently according to age, but that following training most of these age signatures had been reset in the older cohort, back to the levels of the younger group.

LIFT YOUR SPIRITS

Whatever the science – and our rational minds – say about the bene ts of regular exercise, it can still be hard to get up for it, especially on a cold winter’s day.

But one route to a self-motivating training programme, according to science, is to combine a weekly HIIT session with twice-weekly strength training. is combo was shown, in 2019, to be e ective at expressing genes on the mood-boosting, kynurenine pathway (KAT), according to researchers at McMaster University’s Department of Kinesiology.

Tryptophan, found in foods such as turkey, is a precursor to the feel-good chemical serotonin. But to use it, you need to metabolise it, which is what happens on the kynurenine pathway. ankfully, the 12-week HIIT-and-weights combo was shown to increases KAT activity along its neuroprotective pathway, metabolising tryptophan among the men in the study.

Clearly, this e ect requires you to stick at a training plan for more than a couple of weeks, but the post-exercise endorphin hit should get you over any initial speed bumps, before the longer-term changes kick in.

NOW, GO GET IT

Whether you’re looking to kick-start your 2021 conditioning – perhaps with the fat-burning tips outlined in our new Ask the Expert feature – or you want to pack on muscle, this issue of Men’s Fitness has got you covered.

And the science says that if you stick with the training, you’ll not only get tter and stronger, but you’ll be rewiring your genes for permanent health.