Fitness tracker: how it helps with interval running

“My fitness tracker helped me learn to love interval running”

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When writer Miranda Larbi was looking for motivation for her running routine, she found an unlikely source in her fitness watch.

Despite having run umpteen marathons, I’m still the kind of runner who puts very little effort into their training plans. I regularly head out for a 90 minute jog and then wonder why I’ve got tendonitis in my Achilles heel, a sore right hip or a rolled ankle (again). With Covid-19 shutting the gyms for large periods over the year, cross-training and speed sessions were neglected in favour of running long distances. That is, until I got a fitness tracker.

I’ve always used trackers to count steps, but this is the first time that I’ve used a watch to inform my running. It’s become both my coach and my training buddy. The watch face provides all the vital stats on my speed, recovery, mileage – all useful things to know whether you’re going out for an easy run or a tempo session.

Many people think that running is just about putting one foot in front of the other – that all you have to do is get out and go. They’re not wrong, per se, but there’s more to running strong and injury-free. The deeper I’ve gotten into running, the more technical I’ve found myself getting. 

My goals have evolved from simply wanting to be able to run a 5k to shaving minutes off my time, or expanding my endurance capacity to get through a marathon course. I’ve learned that to achieve speed and distance, your best bet is to vary the types of runs that you do (as well as incorporate cross-training into your routine, of course).

Generally, there are four main types of runs: the long run (heading out for 60 minutes or more), the ‘easier’ run (a 30-50 minute jog during which you could talk somewhat effortlessly), the tempo run (slightly slower than your average 5k pace or a slightly uncomfortable speed which you can maintain for about 20 minutes), and intervals (going between periods of active rest and a 3-5k pace running). 

If you’re super motivated, you may already have all of these factored into your weekly workouts. But if you’re like me – somewhat lazy – then you’re probably just going out for that easy or long run. However, I’ve learned that tempo runs, while sometimes unpleasant, are brilliant for developing your anaerobic threshold (i.e. your fatigue limit), which gets you running faster. Intervals are great for teaching the body to utilise energy efficiently. Variety helps to strengthen your cardiovascular system – boosting endurance, anaerobic strength and aerobic capacity. This combined leaves you better equipped to move your body at the speed you choose.

How to track a run: "My fitness tracker has become both my coach and my training buddy."

Of course, you can run without changing up your pace or your distance. My first marathon (in which I had never even run over a 10K previously) was completed without ever visiting a track or knowing what a tempo run was. My training had just consisted of a ton of long runs and easy runs – and by the time I finished the race, I could barely walk to the bag collection point. When I attempted my second marathon, I switched up my training cycle to include one long run per week, plus two interval sessions in the form of treadmill-weight classes – with sprints and squats that left my legs feeling like jelly. I was surprised and pleased to find that I ran that marathon 40 minutes faster than the first, and even had the energy to head to the pub for the afternoon.

The point here is that – at least when it comes to distance – getting used to covering miles will get you around the course, but having speed and power in your arsenal may get you around that course easier and quicker. Gyms are so useful for helping us to get quicker and stronger; treadmill classes are brilliant at forcing you to do hill sprints when you otherwise wouldn’t bother. But in the absence of gyms this year, I found that my fitness tracker helped me replicate treadmill work while on the pavement.

My first attempt at a technical run with my tracker was an interval session at my local park. My Garmin watch suggested a ten-minute warm up, followed by a 6 x 400m at a 5k pace, with a 200m active recovery in between, and finishing with a ten-minute cool down. Again, if you’re not used to tracking runs or having a training plan, you might not necessarily know what your 5k pace is or what it feels like. 

When I set my tracker up, I set a 5k goal time and logged a baseline run so that it would set tasks against my basic fitness. My tracker has the capacity to let you know when you’re running slower or faster than your target time, which is so useful – particularly if you’re only used to doing intervals on a treadmill which sets the speed for you. 

Normally, I find nothing more tedious than the idea of running rings around a track, but as my watch buzzed at the start of each 400m, I found myself feeling surprisingly motivated to run as powerfully as possible. Wherever I felt like I needed the recovery sooner, I glanced down at my watch to see the metres falling away until I was meant to do so – a brilliant motivation that extended my stride, tightened my core and helped me to reach that promised recovery sooner.

A week later and I was back to doing an interval session again – this time at the track in Victoria Park. Since I was running with a friend from the local triathlon club this time, my watch hadn’t set the agenda – so I used the tracker to time laps (4 x 800m). Without a watch, there was no way I’d have wanted to run laps in the first place, let alone aim to do so in a particular time. 

Again, the aim was to run three of the 800m at a 5k pace, with the last one at a 3k pace. Having run intervals the week before, I knew what 5k splits I was aiming for and therefore could shave that time down for the final double lap. It was exhausting (that kind of workout should be), but having the agency over timings and being able to record the session made up for the discomfort.

The other addition to my training was a weekly tempo run, which is the run that feels the hardest but leaves me with that wonderful high of knowing that I’m getting used to pushing my body further. I mean, how often would you push yourself to run as close to your 5k target time as possible when you have no race lined up? 

Before I started using my watch, I’d have gone out for 35 minutes and left the speed up to guess work – which didn’t set me up for where I wanted to be when park runs and longer races resumed. For me, I wanted to turn up to a start line after a year out feeling confident in my abilities. Perhaps more importantly, however, I wanted to turn up injury-free.

My year has been plagued with ankle injuries from overrunning (and landing on my feet poorly). There have been no warm-ups, little cool downs and no attention paid to overloading – meaning that my muscles haven’t had a chance to recover or build back stronger before being piled on with another heavy load. But a found out that a fitness tracker can actually tell you how long you need to rest before your next session, in order to reach optimum recovery – whether you take that advice is up to you. 

Some people can run every day, but most of us can’t – or shouldn’t. Having run 19km by Tuesday night one week, my watch told me that I needed three days of recovery – and after a particularly bad night’s sleep, it pushed that to four days. It was incredible how it was able to assess my body’s vitals and provide personalised advice.  

On a deeper level, trackers can tell you quite a bit about your overall fitness. Mine has been tracking my VO2 max – an important statistic that represents how much oxygen the body uses during exercise at a maximum effort. This gives us an indication of how well our blood, lungs and heart, as well as skeletal muscles, are functioning. 

For running purposes, the higher the VO2 max, the longer you’re able to withstand moderate or high-intensity exercise, so it’s a crucial factor in marathon training. Lots of trackers have a VO2 max function, including Fitbit Ionic, Garmin Forerunner 935, Apple watch 4 and 5, and Jabra Sport Elite smart earbuds. If you’re just starting out on your running journey and you’re looking to improve your fitness more than anything else, that would be a good place to start.

No one wants to become the kind of runner who is obsessed with times – ultimately, running should be about having fun. For many of us, it’s a stress reliever, an act of self-care, or an adventure, but that’s not to say that we can’t also aim to run faster, longer and stronger when we want to – and that’s where tracking can help. 

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5 tips for running with a tracker

1. Decide what you want out of your run. Do you want to be faster, go longer or feel more comfortable? If you’re returning from an injury, bear in mind that although trackers can help, there’s no way of telling the tracker about your dodgy knee or hip – so it’s up to you to set your goals with that in mind, and to seek professional help from a doctor when needed.

2. Join a running programme like Garmin Coach (which I did) or Nike Run Club which can be accessed on your watch, as well as from an app on your phone. It’s like having a PT on your wrist and is the perfect motivation to get out on cold, wintery mornings.

3. Don’t get bogged down by the data. Trackers should be helpful add-ons, not another thing to stress about. Choose what you’re most interested in (whether that’s tracking your VO2 Max, recovery time, mileage or relative effort) and think of the other stuff as useful additions.

4. Join a virtual running club. Most trackers link to Strava or have their own running clubs that allows you to indulge in a little healthy competition - whether that’s against yourself or complete strangers.

5. If you can already run a 5k, challenge yourself to run three different types of runs. Using your tracker, you can try a short and sharp canter (20 minutes), an interval session or an easy run (40 minutes at a talking pace). 

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Images: Getty 

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Miranda Larbi

Miranda Larbi is the editor of Strong Women and Strong Women Training Club. A qualified personal trainer and vegan runner, she can usually be found training for the next marathon, seeking out vegan treats or cycling across London on a pond-green Tokyo bike.

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