How to turn the tables on muscle ageing
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Read time: 3.5 minutes It seems inevitable. The older we get, the harder it'll be to do what we used to find easy. We’re talking daily tasks like:
Much of this comes down to how ageing (and inactivity) impacts our muscles. And these changes make aged muscles look - as well as function - very different to younger ones. But these effects aren’t set in stone. In fact, the muscles of some older people look (and work) very much the same as they did in their “prime”. How ageing impacts our musclesIt's no surprise ageing comes with muscle loss. And of course, the loss of aspects of muscle function, like strength and power, that come with it. But the idea that muscles just shrink with age is a simplistic view of things. You see, not only do aged muscles change in size, but their very composition does as well. To understand this, we need to consider how muscles are made up. Broadly speaking, there are two “types” of muscle fibres: We have type I fibres, also known as “slow twitch” fibres. These fibres are smaller, produce less force, and are more resistant to fatigue. Then we have type II or “fast twitch” fibres. These fibres are bigger, can produce more force, and grow more with resistance training. The larger and more powerful type II fibres are only called upon for tasks where extra force or power is needed. Problem is, these fibres suffer the most with ageing and inactivity. When type II fibres are seldom used, they become disconnected from our nervous system (what’s known as denervated). The motor nerves supplying these muscles literally die off. These denervated muscle fibres then either shrink in size - or are lost completely. And how our body responds to this has big implications for muscle function. The remodelling of muscle with ageingWhen faced with a prospect of losing muscle fibres, our muscles get desperate. To try and retain their capacity to produce force, that is. What happens is the nervous system tries to “rescue” the denervated type II fibres by sending out branches of nearby surviving motor nerves. Trouble is, this process isn’t perfect - with only 60-70% of our muscle fibres being retained by age 75. The result? Aged muscle now has less muscle fibres (particularly type II) and fewer motor units, which are now larger in size (more fibres per motor neuron). So compared to younger muscles, the thigh (quadriceps) muscles of a typical 75 year-old male:
Which ultimately means older muscles can produce:
So not only are we weaker, we move slower, and have less control of our movement. It's easy to see this has massive implications for our ability to perform daily tasks. Effects of lifelong resistance trainingThe good news is the effects of ageing on muscle are not set in stone. Perhaps the best examples of this come from those who’ve managed to remain active for most of their lives. Take masters athletes for instance. Some studies have found strength-trained masters athletes (aged 70-89) had similar muscle (lean) mass to younger control subjects (aged 20-39): Impressive stuff, right? And new data shows lifelong resistance training can preserve the organisation of muscle as well. Masters athletes (aged 73 on average) active in sports like weightlifing or powerlifting for most of their lives were (not surprisingly) stronger and more powerful than inactive or endurance-trained peers. But a deeper dive into their muscle structure revealed some interesting findings. When compared to their inactive and endurance-trained counterparts, the masters strength athletes had:
The muscles of these 73 year-old athletes very much resembled those of people younger than 30.
Is lifelong training needed to produce these effects?The truth is, we don’t know how much training is needed to preserve the size and organisation of muscle as seen in strength-trained masters athletes. It’s possible shorter training periods may have produced similar results. But there’s some indication that once muscle fibres are lost, there’s no getting them back. So it’s important to act as early as we can. What we do know is the benefits of resistance training are seen after a few weeks of very brief training. This 2023 study found older adults improved their strength with just 1 set of leg extensions done twice per week (for 10 weeks). And once these improvements occur, they tend to stick around for a while. A 2024 study found older adults who did 6 weeks of power-focused resistance training (and then stopped) still fared better than inactive controls 6 months later. So it’s ideal to get involved in resistance training as early, and for as long, as possible. But there’s considerable benefit to even brief periods of infrequent training. It's clear that ageing affects our muscles - inside and out. But there’s one thing we can do to counter this. And that’s taking a regular dose of resistance training - however small it may be. The only true miracle drug for ageing muscles. As always, thanks for being here! See you next Saturday, Jackson If you've got a moment, I'd love to hear your thoughts on this edition of The Weekly Exerciser. Send me a quick message or email - I'll reply to every one! PS: Did someone forward you this email? You can sign up to The Weekly Exerciser here. IMPORTANT:The information contained herein is of general nature only and does not constitute personal advice. You should not act on any information without considering your personal needs, circumstances, and objectives. Any exercise program may result in injury. We recommend you obtain advice specific to your circumstances from an appropriate health professional before starting any exercise program. |
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