Strength training is gaining focus right now – but this is why cardio still deserves a place in your routine
Cardio – you either love it or hate it. If you’re not a seasoned runner who spends each Saturday clocking up PBs at your local Parkrun, then it probably makes you feel either bored or overwhelmed. The time-poor among us struggle to fit step counts into busy schedules, let alone go for runs, hikes or bike rides. But, while strength training and lifting weights are finally gaining the focus they deserve, cardio still deserves a place in your routine.
“Cardiovascular fitness is one of the strongest predictors of long-term health,” explains Luke Worthington, a strength and conditioning coach and sports scientist who specialises in training actors for film roles. “But it doesn’t have to be complicated or time-consuming. The key is consistency. The best form of cardio is one you’ll actually do, so find an activity – or activities – you enjoy, do it regularly, and find ways to challenge yourself just enough to keep progressing.”
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Everyone should do two and a half hours a week of cardio
The NHS recommends we aim for 150 minutes of moderate intensity exercise or 75 minutes of vigorous exercise per week.
That could be split into roughly 30 minutes a day, five days a week (moderate), or 25 minutes a day, three days a week (vigorous), points out Dr Christopher Broyd, consultant cardiologist at Nuffield Health Brighton Hospital. “People often ask how hard they should work when exercising,” he says. The simplest way to differentiate between the two effort levels is using the talk test. “If you can talk but not sing, you’re in the moderate range; if you can only say a few words, you’re working vigorously,” Broyd explains. “Alternatively, use the ‘rate of perceived exertion’ where zero feels like sitting on the sofa and 10 feels like a flat-out sprint. Moderate exercise should feel like a five-six and vigorous seven-eight.”
Men may need to do twice as much as women
Activity guidelines are just that, a suggestion for the general population – the ideal amount of cardio varies from individual to individual. New research published in the journal Natural Cardiovascular Research found men may need to exercise more than women to reap the same heart health benefits. In a large-scale analysis of data from over 80,000 middle-aged adults, researchers found that women who did 150 minutes of moderate to vigorous exercise per week had a 22 per cent lower risk of being diagnosed with heart disease, while this was associated with a 17 per cent lower risk for men. Meanwhile, to achieve a 30 per cent cut in risk of heart disease, women needed to do 250 minutes of exercise each week – half the amount men needed to engage in, which was equivalent to almost nine hours (or 530 minutes).
Women needed to do 250 minutes of exercise for a 30 per cent cut in risk of heart disease (Photo: Jose Carlos Cerdeno Martinez/Getty)
If you want to lose weight, aim for 30 minutes or more a day
Ultimately, how much exercise is enough for you depends on your goals. “For fat loss or improved fitness, you may need more frequent or intense sessions, with interval or HIIT training added occasionally for variety and efficiency,” says Broyd. “You’ll know you’re progressing when your stamina improves, your resting heart rate drops, and recovery between workouts feels easier.”
A 2024 review by Imperial College London scientists found aerobic training such as running or cycling did help overweight and obese adults lose weight – but concluded you need to do more than 30 minutes, five times a week, for significant results.
How to test your cardio fitness
The best indicator of whether you’re doing enough cardio is how well you recover from it, explains Worthington. “If your resting heart rate, sleep quality, and energy levels remain stable, you’re probably doing enough,” he says. “Heart rate recovery, meaning how quickly your pulse returns to normal after exercise, is one of the most reliable measures of cardiovascular fitness and overall health.”
Broyd agrees, adding: “The underlying principle is the same for everyone: the faster your heart rate returns to normal after exertion, the fitter your cardiovascular system is.” To calculate your heart rate recovery score, he advises exercising steadily for three to five minutes (go for a brisk walk, a jog or do step-ups). Measure your peak heart rate immediately after stopping. Rest completely for exactly one minute and measure your heart rate again. Subtract the second number from the first. You can do this the old-fashioned way by measuring your pulse with your fingers, though using a heart rate monitor will likely be more accurate.
To keep track of progress, he recommends performing this test every few weeks. “A rising heart rate recovery score means your cardio fitness is improving, but consistency is key so ensure you’re performing it at the same time of day and avoid altogether if you’re stressed or sick.”
In the fitness world, the gold standard measurement for cardiovascular fitness is VO2 max. “VO2 max is one of the strongest overall indicators of cardiovascular health and longevity,” according to Worthington. “It is the maximum amount of oxygen your body can use per minute, measured relative to your body weight and measured in millilitres of oxygen per kilogram per minute (ml/kg/min). VO2 max essentially reflects how efficiently your heart, lungs, and muscles work together to deliver and use oxygen during exercise.”
Things like your age, gender, genetics and training history all influence your VO2 max. “The key is to maintain your own trajectory rather than chase a single number,” Worthington continues. The most accurate way to test your VO2 max would be in a specialist fitness setting, though some wearables give estimations.
Dancing, dog walking, netball, bike rides – just make it brisk
As Worthington says, the best form of cardio is the one that you enjoy. Cycling, running, dance, martial arts, old school aerobics classes, cross training at the gym, your weekly netball match all count, as does walking your dog. Even better if you make it brisk.
What are the most efficient forms of cardio if you’re short on time? If you have the energy for it, but lack the hours in the day, HIIT (high-intensity interval training) sessions can be done in as little as 15 minutes, points out Broyd.
HIIT – which counts as vigorous exercise – raises your metabolic rate, keeps your muscles working and burns more calories in the hours after you finish. However, as HIIT is typically more taxing on the body and takes longer to recover from, “it is not recommended to do it more than two or three times per week,” he adds, “particularly when starting out, and it’s essential to have a solid baseline fitness to avoid injury”.
Why experts love skipping
While for some people, nothing compares to the buzz of a high-intensity group class, Broyd points out that effective HIIT can easily be done on your own. “Focus on a single exercise that uses compound movements to work multiple muscle groups at once, such as indoor rowing, air bikes, running sprints (on a treadmill or outside) or burpees – I often recommend good old-fashioned skipping. Whatever you choose, aim to alternate high intensity 30 seconds bursts with 90 seconds of low intensity for the entire session.” To mix things up, choose different exercises or machines with each session.
Skipping alone can make a good HIIT workout (Photo: Westend61/Getty)
If you can find the time, he also recommends aiming for lower-intensity ‘steady-state’ cardio – which can encompass things like walking, jogging, cycling, or swimming – on other days, a form of active recovery and building an aerobic base. For those who require lower-impact options, try incline walking or circuit-style training performed at moderate-to-high intensity.
“However you choose to do your cardio, remember the gains you are making go far beyond just ‘fitness,’ regardless of how much time you can put in,” Broyd says. “Regular exercise leads to a reduced risk of diabetes, lowers blood pressure and cholesterol, reduces the risk of some cancers and improves mental health and wellbeing – you won’t regret it!”
Find the cardio plan for you
Here, strength and conditioning coach Luke Worthington shares simple principles for incorporating cardio at varying fitness levels:
The retiree who is less active than they’d like
Start gradually with low-impact options such as brisk walking, swimming, or cycling. Short, frequent sessions are safer and more effective than occasional long ones. Focus on making movement part of your routine before worrying about intensity.
The desk worker
Focus on accumulating movement throughout the day and avoiding long periods of sitting. Aim for eight to ten thousand steps daily, and include two to three structured sessions each week that raise your heart rate for around 30 minutes. Consistency and variety matter more than intensity.
The marathon aspirer
Combine long, steady state sessions to build endurance with one tempo session and one interval session each week. The longer runs develop aerobic capacity, while the faster work improves efficiency and VO2 max.
Remember, recovery and strength work are just as important as the mileage and are essential for injury prevention. More people fail to make it to the start line than fail to make it to the finish!