Buy now, pay later: the cost of fatigue at a Grand Tour

Even by Tadej Pogačar’s swashbuckling standards, his late attack on stage three of the Giro d’Italia was unexpected. On a stage set for the sprinters, race leader Pogačar took matters into his hands late on as he poked his head above the peloton with less than a kilometre to go. “He can’t help himself,” commented Dan Lloyd on Eurosport’s ‘The Breakaway’. Geraint Thomas latched onto him and, ultimately, they were both caught, with Soudal–Quick-Step’s Tim Merlier taking the bunch sprint into Fossano. “In the past we’ve seen Pogačar attacking at times when he didn’t need to, simply because he wants to, and then paying for it later in a Grand Tour,” commented co-host Orla Chennaoui.

As the race entered its third week, there seemed no evidence of a diminishing of the 25-year-old’s powers. But theoretically, could there be? Could over-exuberance early in a multi-stage race chafe somewhat further down the line? Rouleur investigates…

Chronic durability

James Spragg is a coach at Tudor Pro Cycling, the Swiss UCI ProTeam owned by Fabian Cancellara. Spragg is also an expert on durability in cycling as that was the subject of his PhD, studied at the University of Cape Town in South Africa. We’ve tapped into Spragg’s durable know-how before where he dug deep into how the top riders are more fatigue resistance than ‘lesser riders’, highlighted by their ability to maintain high levels of work after burning through 3,000kJ of effort.  

We caught up with Spragg once again, this time on the morning of stage 13 of the Giro d’Italia. Spragg’s on recon duty for the 179km pan-flat sojourn and then sprint between Riccione to Cento, which would see Lidl-Trek’s Jonathan Milan win his third stage of this year’s race. “That’s why you can hear sirens, car horns and the craziness of the caravan,” he says. “We’re up close to the caravan every day and it’s… memorable.”

The daily blaring of noise would certainly test the mental resolve of the most zen individual. But what about the physical resolve of digging deep in week one and digging even deeper in week three?

“There’s not actually a huge amount of research in this area, certainly not in pinpointing one effort’s impact early on and the repercussions later,” he says. “I’ve done a fair amount of work on durability but at an acute, rather than chronic, level. That means during a stage rather than over a multi-stage race. I do, however, suspect that’s where the research will head.”

Three-week deterioration

There is the occasional academic insight. We discovered a piece of research by Jose Rodriguez-Marroyo and his team that featured in the March 2017 edition of the ‘International Journal of Sports Physiology and Performance’. Entitled ‘Decrement in Professional Cyclists’ Performance After a Grand Tour’, it didn’t focus on the detrimental impact of a sole effort early on, but it did show just how much a rider’s metrics deteriorated as the three weeks rolled on.

Seven Continental riders – average height 1.76m, weight 67.3kg and annual workload of 30-35,000km a year – undertook two incremental exercise tests, one week before and one day after the Vuelta a España. (Clearly a rather sadistic septet for agreeing to self-flagellation straight after 21 days of racing.)

What did they show? “In summary, the data showed a decline in incremental exercise performance of around 10% after completing a Grand Tour,” read the paper. “The fatigue accumulated by cyclists over the race affected both their maximal and submaximal endurance performance capacity. As a consequence, the exercise intensity increased over the race. Overall, exercise intensity in zone 3 increased by around 8% (or around 20mins), while zone 2 and 1 time decreased by around 3% (7mins) and 5% (13mins), respectively.”

In short, the build-up of fatigue simply made everything harder. Obvious, perhaps, but we’ll reveal, hopefully in a more enlightening manner, what’s happening physiologically shortly. But on a performance level, we ask Spragg, what attribute seemingly suffers the most during a Grand Tour? 

“You definitely lose punchiness,” he says, “but each rider loses it, or maintains it, at different rates, which is influenced by your role in the team. Sprinters will retain their ability to sprint more than the climbers will retain their ability to sprint, for example. And climbers will maintain those long duration efforts more than sprinters. 

“In the same way we feel about daily durability, it matters what you can do after 200km deep into a race. By around today’s stage, fresh numbers are completely out the window. It’s how well you’ve got through the race so far. How do you feel?”

Not just about glycogen depletion

Returning to Rodriguez-Marroyo’s study, that drip-drip fatigue came about due to average stage lengths of 155.5km that ranged from sea level to 2,257m. He actually obtained the data over three editions where the races comprised an average 2% time trial, 46% on the flat and 52% mountain stages.

Each chipped away and contributed to a 10% drop in physiological parameters like power output and VO2max, while heart rate rose. But why? What was the root cause? “Although muscle glycogen can be considered a plausible cause of the depressed performance and is supported by the significant reduction in peak exercise lactate,” read the paper, “the small changes observed for RER at peak exercise argues that muscle glycogen depletion may not be the only cause for the reduction in performance.” So read the paper.

Okay, brief explainer required. Glycogen is how you store carbohydrates, mainly in the liver and muscle, with lactate the byproduct of metabolising carbohydrate for energy. Then you have RER, which is Respiratory Exchange Ratio. This is the ratio between the metabolic production of carbon dioxide and the uptake of oxygen. It’s an indicator of which fuel (basically carbohydrates or fat) is being metabolised for energy. The fact that the RER values in the Vuelta study didn’t suddenly catapult toward 1.0 (the value whereby carbohydrates is the predominant fuel; it’s 0.7 for fat) is the case for muscle glycogen depletion not being the sole reason behind the 10% drop.

Other factors of fatigue could have included – in fact, surely included – hormonal values. The Spanish researchers didn’t measure the state of the endocrine system, but they do suggest that this could have been exhausted by the end of the Vuelta. “It’s safe to say that heart-rate change was due to either a decrease in catecholamine sensitivity or exhaustion of the neuroendocrine system. It’s been shown that cardiac output decreases [how much blood is pumped by the heart each minute] at maximal and submaximal intensities due to reduced adrenergic response in overreached triathletes. This may explain the performance decline (8%) of VO2max and maximal power output reported in cyclists during short-term overtraining.”

Again, a brief explainer warranted. Catecholamines are the principal neurotransmitters that mediate a variety of central nervous system functions, like motor control, cognition and endocrine (hormonal) modulation. These neurotransmitters include dopamine.

As for the neuroendocrine system, this comprises neuroendocrine cells that are spread throughout the body and act like nerve cells, but in this case receive messages from the nervous system and respond by making and releasing hormones. Repeated days of exhausting cycling impacts these systems, resulting in less physical output and a greater chance of illness. Oxidative and muscular damage also plays a part, especially when it comes to heavy legs. But seemingly not with Pogačar whose former coach Inigo San Millan often commented has the greatest powers of recovery – whether it’s between in-stage efforts or between stages – that he’s ever seen.

The Basque exercise physiologist based his observations on the anecdotal and the empirical with the UAE Team Emirates recording daily heart rate variability (HRV) scores to monitor stress and fatigue. 

Nature and nurture

These powers of recovery are like everything in cycling – there’s a genetic element but it’s also trainable. “It’s nature and nurture again,” he says. “The way we think about it at Tudor is that you start a Grand Tour with a barrel of water. After the stage you’ve emptied a little water. But you can add some water overnight. But how much you can put in depends on how well you sleep, how well you fuel, how well you recover and how much you actually used during the stage – what was your role and how hard did you work? No-one will recover fully every day and everyone’s capacity is different; riders recover at different rates. Different efforts hurt different riders differently. Ultimately, you need to do the basics very well and that includes fuelling, hydration, massage and sleep.”

That means trying to finish a race at a similar weight as the start; undertaking a urine test each day to ensure wee’s a nice yellow colour not a rather smelly brown; and daily massage to accelerate the removal of toxins and to ease aching muscles.

When it comes to sleep, Spragg’s Tudor team have snuggled up with the majority of top outfits by hooking up with a sleep partner, Blackroll. One staff member is charged with transporting the riders’ mattresses and pillows between hotels so the likes of Michael Storer (12th on GC at time of writing) can optimise snooze time.

“We also purify the air in the bedrooms,” says Spragg. “This ensures the riders can get as much sleep as possible, wake up the least number of times, and wake up feeling fresh and ready for the next day of racing."

The riders are also encouraged to wear Dagsmejan Recovery Pyjamas. (I know, who’d have thought.) According to the marketing, those pj’s feature “the revolutionary Nattrecover fabric that contains responsive energising minerals, which helps to oxygenate the muscles and to regulate body temperature”. The jury’s out on the impact of these, especially if you’re a rider who likes to kip au naturel. But we’re sure they’re very comfortable.

“We also taper into every main race,” explains Spragg. Tapering is where you look to reduce workload to replace fatigue for freshness for peak form. “Each of our riders has a standardised taper protocol over three to five days that is then individualised, so it’s slightly different for all eight riders I train. It’s typically guided by a combination of the data – for example, what their maximum power looks like – and how the rider feels.

“When you line up at a Grand Tour, it’s about having as little chronic fatigue as possible coming into a race. It’s important that they feel good from day one, and something you think about on a macro scale. When I draw up a rider’s plan, one of the key things is building in periods of recovery. Without recovery, the rest goes to shit and you’ll see a big drop-off in performance across a race and season. Getting it right is where science meets the art of coaching.”

So, there you have it. Will Pogačar come to rue this stage three sprint? At time of writing, there were few signs, his only regret probably that he didn’t win the sprint. He is a racer through and through. But it’s clear that even with his noted powers of recovery, he is human and will see a detriment in performance before the race reaches Rome on Sunday. Will the depleted glycogen, endocrine battering and muscle damage be enough to prevent Pogačar becoming only the eighth rider in history to win all three Grand Tours? Let’s just say we wouldn’t bet your appreciated subscription on it!