What does longevity really mean? 

“Longevity isn’t just about adding years to your life,” says Jo Rowe. “It’s about how many of those years you spend feeling capable, strong and mentally sharp.” While life expectancy is rising – most men are now living into their late 70s and beyond – Jo warns that healthspan isn’t keeping pace. “We’re surviving more thanks to medicine, but around 80% of adults now have poor metabolic health. That’s why longevity is a growing conversation – it’s about protecting quality, not just quantity.” 

Isn’t longevity something to think about later? 

“Not even close,” says Jo. “Ageing doesn’t suddenly begin at 50. The foundations are laid in your 30s – and often earlier.” Muscle mass, insulin sensitivity, mitochondrial function and metabolic flexibility all start to decline quietly unless they’re actively supported. “You might not feel it immediately, but the body is always adapting – either in your favour or against you.” 

If you could focus on just one thing for longevity, what would it be? 

“Muscle,” Jo says. “Without question.” Muscle is metabolically active tissue, meaning it directly affects blood sugar control, hormone health, mobility, balance and bone density. “From the age of 30, men lose around 1% of muscle mass per year unless they’re strength training. Over decades, that adds up.” Her advice is straightforward: resistance training at least three times a week, paired with adequate protein intake – around one gram per kilo of bodyweight per day. “Strength training is one of the strongest predictors of how well you’ll age.” 

So, how should you be training? 

“This is where a lot of guys go wrong,” says Harrison Stevens. “Most men train for how they want to look now, not how they want to feel in ten or 20 years.” In your 20s, he explains, you can often get away with inconsistency, poor recovery and pushing hard without much consequence. “Your 30s are about building durability. Longevity means staying strong, mobile and injury-free as life gets busier – not constantly rehabbing something.” The biggest mistake? Treating intensity as the goal. “A lot of men chase maximum output every session – same lifts, same loads, same intensity – without thinking about sustainability. Looking good and feeling good do overlap, but longevity training requires a shift from maximum output to sustainable output.” For Harrison, training for longevity means covering three non-negotiables: strength, cardiovascular fitness and movement quality. “You still want to train hard – but intelligently. If one of those pillars is missing, something eventually breaks.” 

Where does cardio come in? 

Cardio is often either overdone or ignored entirely – neither of which supports longevity. Jo points to Zone 2 training as a foundation. “This is moderate-intensity movement at around 60-70% of your max heart rate – think brisk walking, steady cycling or swimming. It improves mitochondrial health, cardiovascular efficiency and metabolic flexibility, which are all key markers of long-term health.” Harrison adds that higher-intensity work still matters – but in controlled doses. “Short bursts of maximal effort – hill sprints, rowing, bike or ski erg – improve VO₂ max, which is strongly linked to longevity. The higher your VO₂ max, the healthier you tend to be.” The key is balance. “You don’t need to do everything every day,” he says. “But across the week, you should be touching both low-intensity aerobic work and one higher-intensity session. Longevity comes from variety, not punishment.” 

Is sitting really the new smoking? 

“Kind of,” says Jo. “You can train three times a week, but if you’re sedentary the rest of the time, you’re missing a huge piece of the puzzle.” She’s referring to NEAT – non-exercise activity thermogenesis – the calories burned through everyday, low-effort movement like walking, cooking, standing or tidying. “These small movements improve insulin sensitivity, circulation and overall metabolic function,” Jo explains. Harrison agrees: “Movement supports recovery. Staying active between sessions keeps joints mobile, boosts circulation and helps the body bounce back – so you can train consistently for years, not just grind through a season before something breaks.” 

What role does diet play? 

Jo points to the world’s longest-living populations – those in the Blue Zones – for clues. “Their diets are plant forward, low in ultra-processed foods, and built around legumes, veg, fruit, nuts, seeds and whole grains.” The result? Better gut health, reduced inflammation and improved detoxification. “One smart rule is to eat until you’re 80% full, then stop,” Jo says. “That, combined with cutting back on sugar, alcohol and processed foods, is a game-changer.” For nutrients, focus on antioxidants. Jo suggests vitamin C, vitamin E, selenium and zinc – all essential for reducing oxidative stress. “Tomatoes are great for lycopene, which supports prostate and heart health. Brazil nuts offer selenium for skin and cell repair. Zinc, from shellfish and seeds, supports immunity and testosterone.” 

Is intermittent fasting worth doing? 

“Yes – when done well,” Jo says. “Fasting supports autophagy – the body’s internal clean-up process. It removes damaged cells, reduces inflammation and improves insulin sensitivity.” But she’s quick to add it doesn’t need to be extreme. “Even a 12-hour overnight fast – say, 8pm to 8am – offers benefits without stressing the body.” 

What else matters beyond diet and training? 

“Sleep is the foundation,” says Jo. “It’s when your body repairs, detoxifies and regulates hormones. Without it, everything suffers – appetite control, blood sugar, mood, recovery and longevity.” And don’t overlook toxin exposure, she adds. “Plastics, pollution, cleaning products – they all place a load on the body.” Her practical swaps? “Use glass or stainless steel instead of plastic. Drink filtered water. Choose non-toxic cleaning products where possible.” She also suggests supporting detox pathways with fibre-rich food, proper hydration, and, if available, sauna use. 

The takeaway? 

Ultimately, longevity isn’t about perfection – it’s about consistency. Start here: 
 • Lift weights 2-3 times a week 
 • Walk daily & move often 
 • Do both low-intensity cardio & short bursts of intensity 
 • Eat protein at every meal & favour plant-rich food 
 • Finish eating 2-3 hours before bed 
 • Sleep well, and often 
 • Reduce plastic & toxin exposure where possible 
 • Manage stress through movement, connection & routine

For more, visit JR-Nutrition.co.uk & ThirdSpace.London

DISCLAIMER: Features published by SLMan are not intended to treat, diagnose, cure or prevent any disease. Always seek the advice of your GP or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, exercise or other health-related programme.