Dumoulin placed second to Froome in the Giro in May and two months later, he raced three weeks in France, ending with a time trial stage win and a podium spot at 1-51 minutes behind Thomas. It took its toll.
"Actually, I only trained a bit after the Tour de France, for a week and a half," Dumoulin told De Telegraaf.
"I never came out of a Grand Tour as broken as now. I said two weeks after the Tour, to Thanee [his fianceé - ed.] that I did not know what was going on with me. I felt like a zombie walking around after the Tour."
Dumoulin had his best Tour, the first time he had aimed at the overall classification in France. In each of Thomas's two breakthrough Alpine stage wins – at La Rosière and Alpe d'Huez – the 27-year-old Dutchman placed second.
The three weeks came to an end with a time trial stage win in the world championship jersey ahead of Chris Froome (Sky), who moved from fourth to third overall on the day in Espelette.
"I really did not feel good on my first training rides. I then really wondered if it was still possible to build a form peak towards the World Championships," Dumoulin added.
"Fortunately, I think cycling will only become more fun. For me it is really no punishment to ride for five hours through the Ardennes. Last week we went on holiday for a few days near Siena in Tuscany. There, I trained for the first time where I noticed that my body could handle it again."
Dumoulin can't remember how many criteriums he rode after the Tour ended in Paris, but it was "a lot." He completed his first official race, the four-day Tour of Germany, last weekend finishing fourth overall. That should be it between now and the World Championships in Innsbruck, where he will try to defend his time trial title.
"For the time trials, you do not need race rhythm anyway, but for the road race that can be sensible. Anyway, I am always good after a training period. I'm not worrying about that," he continued. "For the time trials, you have to do long blocks, while you need the punch for the road."
Dumoulin won the time trial rainbow jersey last year in Bergen, Norway, ahead of Primož Roglič (LottoNL-Jumbo). The Innsbruck time trial, 52.5 kilometres, takes place on September 26.
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