[caption id="attachment_25483" align="aligncenter" width="300"] I've had 65 in a lab a few years back, and sometimes Garmin gives me as low as 50—to be fair, generally on a new device when, maybe, the data is not all there.[/caption] Garmin VO2max Optimisation - how to use Garmin's tools to boost it and 5 reasons why you're doing it wrong VO2max is one of the key measures of cardio fitness. It's also a great indicator of health span and a metric that we should all do our best to maintain as high as possible. In less technical terms, it measures how much oxygen each Kg of your body can use during a maximal effort. To increase VO2max, you must get fitter and/or lose fat. Muscles process the oxygen; fat doesn't. The only caveat I would add about VO2max is that it fails to consider how efficient you are at the exercise. Thus, a more efficient runner could beat a friend with a higher VO2max if their running technique was more efficient. Supershoes would make a difference, too, but hopefully, you get the point. https://the5krunner.com/2025/08/27/garmin-vo2max-scientific-study-roasts-it-and-loves-it-when-a-it-dpends/ Reason #1: why you might be failing to improve VO2max - lack of high-intensity efforts High-intensity workouts are the most effective at improving VO2 max; interval training is usually recommended. Garmin Coach might offer AMRAP exercises for the HIIT activity profile or Tempo runs/rides at 90% VO2 max for 40 minutes for cyclists and runners. High-intensity efforts are the stimuli that force aerobic adaptations. You have recovery periods between VO2max intervals, and this recovery means you can spend more time at high intensities than you could from a single continuous workout. Reason #2: Why you might be failing to improve VO2max - Lack of recovery Hard exercise is bad for your body in the short term; it destroys and depletes muscle. Recovery time is when your body repairs, rebuilds, and makes you stronger. That's when the adaptation happens. You want adaptation. You need to recover. Single-minded, dedicated people can very often overlook adequate recovery. It feels counterintuitive. Check the recovery time on your Garmin watch. It's the recovery time until the next hard workout. Garmin's recommendations for recovery time will only be correct if you have your power/HR zones and other personal parameters set correctly. Go easy or rest on recovery days. Go hard...very hard, on interval days. Reason #3: Why you might be failing to improve VO2max - Training Monotony You might like specific workouts, maybe because you are good at them. But you wouldn't train for a 5K by only running 5K in training. The best training has variety. Consider high and low aerobic efforts plus anaerobic efforts, strength training and plyometrics, improving technique with drills, and understanding race psychology. Garmin's running plans have improved in recent years, adding adaptive capabilities and strength components. Even pretty good runners will benefit from them. Garmin Training Load Balance is one of my favourite Garmin tools on my Forerunner 970 and shows how your cumulative recent efforts stack up against the ideal efforts across different intensities. Garmin's plans (the Run and Cycling Coaches) specifically adapt workouts to target VO2max improvements. Reason #4: Why you might be failing to improve VO2max - Diminishing Returns With over five years of solid training, you will likely plateau. Sometimes, you will have to go through periods when you reduce (periodise) training, and this may well see VO2max fall before rising again later. Garmin lets you look at these longer-term VO2max movements in chart format to understand the dips and climbs. https://the5krunner.com/2025/09/03/garmin-fenix-8-pro-microled-review-first-look/ Reason #5: Why you might be failing to improve VO2max - Genetic Potential Not everyone improves at the same rate, and we all have different VO2max ceilings. Sadly, these ceilings drop progressively every year for adults. I once calculated that my maximum possible 5K PB time would fall by 6 seconds yearly. Understand VO2max in more general terms and be realistic in your expectations. Continue to challenge yourself and recover through consistent sleep patterns. 99.99% of people will be able to improve their current VO2max - the challenge is on. You know what to do. Garmin's Forerunner 970 is the best running and triathlon watch with every Garmin feature, including VO2max. Garmin Fenix 8 Pro has the same training features but in a more rugged and premium shell. Optimising VO2max For Runners The classic VO2max booster for runners is three one-mile or one-kilometre runs at a maximal pace with about three minutes of rest between efforts. You could do five reps, but it gets hard for almost everyone to execute more than five maximal efforts like this. A rule of thumb would be to have two easy days before your next similarly hard effort—but you have Garmin's plans and your on-watch tech, so you don't need my advice. You have to run fast to get fast. However, you only have to run fast to boost your VO2max more quickly; most exercises (running) will increase VO2max to some degree. [sc name="scgarminforerunner970" ][/sc] [sc name="scgarminfenix8pro" ][/sc]
