They were two of the most striking breakthroughs in recent times: Stephanie Davis, a 30-year-old with a full-time job in finance, running a PR of 2:27:14 to win the British Olympic Marathon Trials in London in March; and Beth Potter, a 29-year-old Scottish triathlete, running 14:41 at the Podium 5K in Lancashire, U.K., two seconds quicker than the world record.
What made their performances so intriguing is that, unlike most of their world-class rivals, Davis and Potter are not high-mileage runners. Speaking to Runner's World, Potter said she runs just 30 miles a week, while Davis said she averaged 88K a week (54 miles) on the buildup to her PR.
It begs the question: Is high mileage really necessary? And could cross-training be an underused weapon in our search for faster times?
Both Potter and Davis had tried higher mileage in the past, with Potter logging 70 to 90 miles a week when she was focused on running the 2016 Olympics, where she competed in the 10,000 meters.
'I was working full-time as a teacher back then,' Potter tells Runner's World, 'so I didn't really have time to swim or run.' In 2018 she switched to triathlons, and these days she's a full-time professional athlete. But she was shocked by her 5K performance.
Davis, meanwhile, always found lower volume worked for her, but she experimented with an increase last summer and tried 70 to 75 miles a week. A subsequent bout of IT band syndrome sidelined her for three months. As a result, the routine that led to her breakthrough, much like Potter's, put heavy emphasis on cross-training.
Potter typically logs 25 to 30 hours a week in training, with just four of those hours spent running. She does one easy run, one long run and two workouts: intervals on a Tuesday and tempo work on a Saturday. But she also rides her bike five times a week, swims for 90 minutes five days a week, and does two strength sessions along with one yoga session.
Davis, meanwhile, makes every Monday a 'non-impact day,' swimming in the morning and going on the elliptical or riding her trainer in the evening. On Tuesdays she runs intervals on the track or road, and incorporates two other key sessions-tempo work on Thursdays and a long run on Sundays. She supplements her running with six to seven hours of cross-training each week, along with two strength and conditioning sessions and what she calls 'an abundance' of stretching.
'The cross-training approach has always worked for me,' Davis tells Runner's World. 'It helped me add quality to those run sessions because I'm not carrying as much fatigue.'
How can you make it work for you? These seven rules will help.
1. Find the right cross-training modality for you
Some activities, like swimming, require proper technique. For others, like cycling, you'll need the proper equipment and fit. But using an elliptical machine, on the other hand, has a lower barrier to entry, as long as you can access one at a gym.
'It depends on your history,' Jessica O'Connell, a 2016 Olympian in the 5,000 meters for Canada and a cofounder of Grit Athletic Coaching, tells Runner's World. 'If you grew up swimming or cycling, that's a no-brainer. But if you didn't, those activities can be really challenging.'
Her preference is for the elliptical and aqua jogging. 'The more weight-bearing and the more similar to running, the better,' she says, 'but it doesn't have to be.'
2. Start slowly
The advice for cross-training is to introduce it gradually, according to coaches and athletes. Potter said when she transitioned from running to triathlons she developed foot and hamstring issues due to her positioning on the bike.
'You have to be careful,' she says. 'You can't go and smash cross-training every day. The best way is to go for time, to go easy but spend time doing it and build up gradually because you will be a bit tired.'
3. Use it as a safer way to add volume
The amount and duration of cross-training depends on your current routine. Are you training for a marathon? Already maxing out your hard sessions? Or trying to increase general fitness?
For runners who want to increase their mileage but are injury-prone, adding some short cross-training sessions of moderate-intensity can make up for a lack of running mileage, O'Connell says.
Ben Rosario, head coach at Northern Arizona Elite, says his group uses cross-training to keep mileage high while reducing risk of injury.
'We typically used cross-training as a tool when an athlete was coming back from an injury, but a few years ago we began using the Alter-G (anti-gravity) treadmill for an athlete's training, because he had bone density issues,' Rosario told Runner's World. The athlete did 25 percent of his weekly mileage on it and had success.
Lately the group has been experimenting with using the ElliptiGO as part of some athletes' training, even when they're healthy, because they're able to get more aerobic work in without the pounding and stress that puts on muscles and tendons.
For recreational runners, O'Connell believes some of the training outside of workout days could be replaced with cross-training without sacrificing performance.
'To be good at running you need to run, but you don't need to run all of your sessions,' she says. 'As long as you're touching running and dealing with gravity a few times a week, it's okay if the other days are cross-training.'
If you're already doing two hard running workouts a week, she says you can replace an easy run with your cross-training activity of choice, starting at 30 minutes and working up to 60 minutes.
© Martin Rickett - PA Images - Getty ImagesBeth Potter competes in the 10,000 meters at the 2018 Commonwealth Games.
4. Or a safer way to add intensity
For runners doing just one hard workout a week and the rest of the week is easy running, O'Connell recommends adding a hard cross-training interval workout.
One of her favourites is 10 x 3 minutes with 30 seconds recovery, or a pyramid of intervals going from 1 minute hard up to 5 minutes, before going back down, taking 60 seconds recovery throughout.
With cross-training, she says, 'intervals can be quite a bit longer and your rest quite a bit shorter.' That is especially true for swimming or aqua-jogging, where your heart rate is typically lower than it is when running at a similar effort.
For those preparing for a marathon, O'Connell believes runners looking to experiment with cross-training should not tinker with their long run to ensure their legs are able to adapt to the distance.
'But you could use some easy cross-training to offload your midweek mileage if your legs are feeling tired,' she says. 'Or you could add it to the end of a running session to get a longer session.'
5. Bounce back faster from injury
Most runners only resort to cross-training when they're injured. Rosario has seen how beneficial it can be in that area, noting how Aliphine Tuliamuk used an ElliptiGO through the summer of 2019 when she had a femoral stress fracture. It helped her put down a great fitness base and a little more than two months after she started to run again, she finished 12th at the New York City Marathon. Three months later, she won the U.S. Olympic Marathon Trials.
'She really cranked on that thing,' Rosario says. 'The anecdotal evidence from our team is that if you can do some quality cross-training [while injured] it's pretty advantageous because from an aerobic perspective you'll be ready to go when you get back; it's just about letting the legs catch up.'
It's something O'Connell has also found.
'I've been [injured] for a month or two and been back to world championships standard levels within a few weeks, and that definitely wouldn't happen if you're sitting on your butt,' she says. 'I also think there's a mental-health component: Athletes like to sweat, they like to feel they're being productive, and you get that through cross-training.'
For those who find themselves unable to run, it's possible to cross-train at a higher intensity than you might be used to as a runner, as long as the activity doesn't aggravate your injury.
'If the injury allows for hard cross-training,' Rosario says, 'if the athlete takes advantage of that and hits the cross-training hard, when they come back and are ready for land, they can be pretty fit.'
For Davis, with gyms closed in England through the fall due to the pandemic and her IT band issue lingering, she used the turbo bike trainer she had at home and completed tough online training plans using Zwift.
'It was an absolute sweat-fest, but it kept me really fit,' she says. 'You can then bring a lot of that fitness into your running. I don't know if I'd run a 2:27 marathon off bike training [alone], but it helped me not to lose fitness.'
6. Keep an eye on your heart rate
O'Connell says monitoring heart rate is the best way to ensure you're getting the right training stimulus, and runners who are injured should not see it as a reason to simply hammer cross-training workouts every day.
'I polarise my cross-training and I have easy days and hard days, just like I would when running,' she says. 'Keep in mind your heart rate will be different on every modality. It's always going to be lower in the pool; it'll probably be lower on the bike because you're not working against gravity, so establish norms.'
Davis, too, says her top tip is to wear a heart rate monitor. 'When I'm marathon training, everything I do in cross-training is at an easy level,' she says.
7. When you have some experience, push the envelope from time to time
While there is no true replacement for running, Rosario believes more runners will add cross-training to their routine in the coming years, seeing it as a safer way to train harder.
'Let's say you do a hard running workout in the morning,' he says. 'Who's to say you couldn't do a hard swim in the afternoon? The lungs can handle it, the heart can handle it; it's the legs we have to worry about and a little bit of our overall energy pie.'
The key is being smart with your overall energy, Rosario says. 'As long as you're spacing it out and recovering, we can probably handle more aerobic work than we thought.'
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