FAREWELL BONKING?
Why hitting the wall could be a thing of the past
“I didn’t eat anywhere near enough and it was like someone pressed an o -switch in my body. I became lightheaded and experienced tunnel vision; still pedalling but barely moving.”
These are the words of committed recreational endurance athlete Martyn Brunt whose plummeting sugar, power and cognitive levels on a Lanzarote training ride ended with him in the frenzied state that all endurance sports people dread: the bonk. Otherwise known as hitting the wall, it’s characterised by a sudden and overwhelming fatigue because of an acute shortage of fuel.
How could it happen to this well-prepared cyclist with a deep understanding of his body and conditioning? Brunt knew his wattage through his power meter, his beats per minute were leaping out of his handlebar-mounted unit, but his fuelling status was left to feel. In this
empirical, data-driven world of modern cycling, it was akin to taping over the petrol gauge and hoping for the best. If only he’d had access to his blood-sugar levels, he could have steered away from the brink well before he got there.
Metabolic value?
Should you follow professional cycling, you may have come across Supersapiens already. Ineos Grenadiers, the world’s most lavishly backed and arguably best team, use Supersapiens’ glucose monitoring product. Team principal Dave Brailsford is also an advisor to the company and has a long track record of taking an interest in nascent scientific developments that promise to add layers to his push for ‘marginal gains’.
The product also recently hit the news when the UCI banned it – and other devices that measure metabolic values – from competition, just in time for the 2021 Tour de France. For cyclists who like to combine their cycling with some swimming and a run, Supersapiens has become the new title sponsors of the Ironman World Championship in Hawaii. This brand awareness and reach is no accident, either, because it recently brought in $13.5m of funding, with new investment from Wahoo founder Chip Hawkins and Eric Min, founder and CEO of Zwift. With a lot of fuss from some of the sport’s biggest hitters, we were keen to put it to the test.
Core to the system are biosensors, built, refined and supplied by American multinational healthcare firm Abbott Laboratories, who were one of the first companies to create continuous glucose monitors, or CGMs, for diabetics back in 1999. More recently, Abbott launched the first CGM device, the FreeStyle Libre Pro, that didn’t need a fingerprick test. Now, the technology’s made the leap into sport. More specifically, into my arm…
For sports people, there’s still a prick for blood involved with Supersapiens’ biosensor but it’s on your upper arm, rather than your finger. An applicator akin to an inflated passport stamp was pressed against my skin, depositing an ultra-thin filament that’s stuck into place by an adhesive sticker. This then measured glucose levels in the interstitial fluid (the fluid between blood vessels and cells). It’s completely painless.
I had been o!cially biohacked and would remain that way for the test period. “Each biosensor lasts for 14 days and nights,” founder Phil Southerland informed me just prior to insertion. “When inserted, you don’t notice it,” he added. “It’s very rare that you’ll hit a nerve – less than 1 per cent do.”
But forget comfort, it’s the data and lifting the empirical lid on blood glucose that we’re interested in. Beyond an intriguing premise, what practical a"ect can it have in the real world? Have I already had my final bonk?
The sensor passes data to the Supersapiens phone app that displays a mass of glucose measurements, designed to arm you with the knowledge to fine-tune your fuelling strategy. The sensor also reaches out to a range of Garmin watches, including the Fenix 6 and Forerunner 945, albeit you still need your phone, with the app acting as a conduit.
Not surprisingly, Wahoo computers, with the links to its founder, is also mooted to display glucose data in the near future. Zwift, too, will surely have an extra widget down the line. Supersapiens is also close to launching its own watch, the Reader Version Zero.
The app relays a lot of glucose-related information to identify trends that either need tweaking or a complete overhaul. These include: ‘glucose variability’, which is an indicator of relative stability of your blood glucose over a 24hour period, with a lower mg/dL (milligrammes per decilitre) signifying better stability; ‘average glucose’, again for the previous 24 hours that you can compare against a pre-set target; and ‘glucose zones’. These are a breakdown of the percentage of the day you spend between anything from lower than 60mg/dL to over 140mg/dL, and are separated into inflammation (over 140), glucose loading (91-140), adaptive state (70-90) and impaired recovery (below 70). Too high is bad, too low is bad, in the middle is good but better if below the middle.
Sensor experience
Knowledge is power and, when it comes to Supersapiens, that power comes at a cost. More precisely, €65 (£55) for the trial pack including one two-week biosensor; €450 (£380) for three months; €780 (£666) for six months; or a monthly subscription of €129 (£110). To maximise its purported benefits requires trends, which requires data, so you will need more than the trial pack.
“You should spend the first week living your life the way you would normally,” says Southerland. “If you eat a bagel, what happens? If you eat an egg, what happens? At the end of week one, look back at your glucose average. If it’s 110mg/dL and you’re looking to cut weight, set your target to 100mg/dL. Over 24 hours, this would be 2400mg/ dL. Once you set your exposure, you can plan more e!ciently, over time and in the short-term.
“Take one of the key metrics for cyclists, which is power-to-weight. You’re looking into what to have for dinner. You look at the app and it shows that you’re under-exposed to glucose that day. You’re not looking to lose weight at the moment, so you can have that burger and fries you were planning. Then again, you look and you’re over-exposed to glucose. You’ve had too much throughout the day, so you know it’s salad time with a protein hit, like lean chicken. You might go to bed a little hungry but that’s fine because you’ve reached your exposure for the day.”
When it comes to Supersapiens, glucose is king, queen and the Devil rolled into one. I soon discovered that a weekend at an ale festival sends results through the roof, as did drinking squash. Not surprisingly, porridge delivered a gentle, stable rise, as did grazing on nuts. When it came to riding, a two-hour journey fed back what I’d anticipated: that my glucose levels
The product also recently hit the news when the UCI banned it – and other devices that measure metabolic values - from competition, just in time for the 2021 TdF
slowly decreased before rebounding back when I consumed an energy gel before this sugary benchmark lowered over time.
Rides like these – in fact, any form of exercise – can then be filed under the ‘events’ tab for further scrutiny: what types of sugar should I be eating; is sucrose enough or should I add fructose? How many gels should I consume each hour? Carb drink and gels, or electrolyte drink and gels? And, of course, why did I bonk? Where did I go wrong?
“We had a female athlete who’d DNF’d her last two Ironman events, bonking epically in the runs,” says Southerland. “In advance of her third attempt, we put a sensor on her and saw that she was hypoglycaemic. Like most endurance athletes, she was busy – family, training, job – and she forgot to eat. We told her to double her carbohydrate intake, which stabilised her bloodglucose levels. Lo and behold she stormed it, breaking her personal best by a huge amount.”
Sugar, sugar
Hypoglycaemia is anything below 72mg/dL; hyperglycaemia is anything above 125mb/dL. Southerland has experience of these extremes. These outliers are clear signals of diabetes, of which Southerland is one – and one who defied doctor’s wisdom to forge a long, healthy and successful cycling career. He’s the founder of Team Type One, an organisation comprised of over 170 athletes with type-1 diabetes, and Novo Nordisk, the UCI ProTeam who made moves in the breakaway at Milan-San Remo this year. One of their disciples, Joonas Henttala, recently won Finland’s National Road Championships.
“For me, continuous glucose monitoring has proved a gamechanger,” Southerland says. “As a diabetic, I’ve switched from laboriously checking my glucose levels 20 times a day to constant feedback. It’s essential. I’ve seen in my world how a plate of pasta might have one diabetic needing six units of insulin, for another four units, another two… everyone’s di erent. It’s the same in the rest of the population; we all respond di erently to food.”
We all respond di erently to glucose; we all store di erent amounts of glycogen (the body’s storage form of glucose). Both are nectar to the active cyclist and, says Southerland, absorption and assimilation are a ected by over 40 variables including nerves, sleep and altitude.
This is bread-and-butter to exercise physiologist Bob Murray, whose academic background is in carbohydrate metabolism; professionally he was Gatorade’s sports laboratory director between 1985 and 2008. In short, he’s an authority on all things cycling- and sugar-related.
“I haven’t had a chance to use Supersapiens yet,” he confesses, “but, in theory, it certainly sounds more usable than our historic method of measuring blood glucose levels when exercising, which was via a catheter. Of course, having not used it, I can’t vouch for its accuracy.”
Nor can I, frankly. Without a more clinical comparison, it’s impossible for me to say how accurate my glucose numbers are. All I can say is that results were consistent, albeit with the occasional unexplained fluctuation, like glucose levels going through the roof 30 minutes into a game of five-a-side football. My daily average
came in at 103mg/dL, which seems to match my sugar intake. Still, hitting the recommended 90mg/dL became a goal with the idea of shedding a few performance-impairing pounds. As did keeping variability down as low as possible as peaks and troughs are a fast-track way to damaging your insulin system.
Another potential benefit of Supersapiens’ product, certainly for the high-performing riders out there, is in maximising the idea of fasted training – the popularised nutrition strategy of cutting out carbs before and during a ride, usually before breakfast and relying on fat burning as fuel. This trains the body over time to only use the sparse muscle glycogen stores for when it’s most needed, at the end of a tough ride.
“How much glycogen we can store in the muscle and liver is impacted by several factors including fitness, but we’re looking at around 400-700g,” explains Murray. “This then a ects your subsequent blood-glucose levels, which ultimately will help you track more accurately the performance parameter that you’re looking to improve.
“To take the idea of training low to compete high, the idea being that your glycogen levels are reduced so you become more reliant on fatburning to fuel your rides. If you can measure this, you can find a sweetspot that ultimately improves your aerobic capacity without feeling too dangerously drained like you often might feel when riding fasted.”
It’s a tactic of Ineos Grenadiers, who has used Supersapiens for the past year to measure how its riders adapt to low-carb sessions. Nevertheless, returning to what we stated at the beginning of this feature, the team won’t be using Supersapiens’ product, or other devices that measure metabolites, at races after the UCI banned its use in-competition in June.
EF Education-NIPPO Cycling team boss Jonathan Vaughters took to Twitter to denounce the decision: “On brand. If they can’t understand it, they ban it.” Then again, a product like Supersapiens does seem at odds with the UCI’s no-needle policy, albeit this applies to “artificially improving performance or recovery” like injecting vitamins or antioxidants. In the case of Supersapiens, it doesn’t directly impact your body in search of stronger riding, just delivers information with the aim of doing so.
And for us, that’s where cutting-edge technology like this becomes something of a tougher sell. While the app’s clean and attractive, this is a relatively new field to many, resulting in swathes of data that can be hard to interpret and act upon without educated input, the main takehome being that low variability and a constantly flattish curve are good. So working with a coach or nutritionist would potentially make this a useful tool and, in our pedalling paradise, it’s entirely possible that it could make the bonk a thing of the past.
Yes, all this comes at a cost, but for those who can a ord to tap into Supersapiens’ data, here lies prized information that can turn an unmitigated disaster into glory.
Another potential benefit of Supersapiens’ product, certainly for the highperforming riders out there, is in maximising the idea of fasted training