When comparing the curves of the Conconi test and the lactate test it shows that the Vd, the running speed at the deflection point, and the AT, the running speed at the anaerobic threshold, correspond well. See curve below:

The lactic acid or lactate curve is determined by means of a progressively increasing maximal exercise test in the laboratory. Per time unit, depending on the protocol, the load is increased. During the test there blood is regularly taken for lactate level determination. Also, HR and / or speed and / or the delivered wattage are continuously registered.

Ergometer test
Treadmill test

It is interesting for cyclists to know which HR or Wattage is the best for a specific workout. With the Wattage and the HR, at a certain lactate level, individual training schedules can be created so that training is optimized.

The lactic acid curve shows a gradual rise in the lactate level as the intensity of the exercise increases gradually. The different colours* indicate the different training zones. Each training zone corresponds with certain HR values and / or wattages that can be determined separately for each rider.


Table of synonyms

OBLA = onset of blood lactate accumulation

Gray zone + Green zone + Orange zone = aerobic energy supply zone. Training in this range improves endurance. During the training there will be no accumulation of lactic acid. There is sufficient oxygen present. The production of lactic acid is in equilibrium with the breakdown of lactic acid.

Red zone = training in this area enhances the anaerobic capacity. The workouts are intensive up to maximal.  A high anaerobic capacity is decisive for performance. Lactate values can be extremely high. There is not enough oxygen present and lactate is formed. The production of lactic acid cannot be neutralized by the body.

Another example how individual training advice can be given using the lactate curve. It is more complicated than presented here, but the principle must be clear.

The lactate test as described here is still widely used. In order to provide a better training advice. There is nothing wrong with that. As part of the application procedure for new riders the test is also used. In that case the result of the test is often decisive if the rider gets a contract with his new team or not. Based on my experiences I have serious objections against this procedure.

I tested a rider 10 days before Paris Roubaix in 1990. He scored extremely moderate and did not exceed 410 Watts. Whether he had done his best was evidenced by his high lactate of 11 mmol / L. A better performance was not possible. He won Paris-Roubaix after a long solo with the smallest possible margin he passed the Canadian Steve Bauer, who shortly before the finish joined him. Paris-Roubaix is one of the toughest classics that exist. A hellish journey, 265 km long, along paths paved with cobblestones. Whoever wins knows that his cycling career was successful. That day Eddy Planckaert was de winner despite his poor test of 10 days before. That day he became a hero for the rest of his life who is still idolized and adored. He is held in higher esteem than the king of Belgium and famous football players, movie stars and popular singers stand in his shadow. And that all because of a difference of maybe 1 cm on the finish, Steve Bauer finished second but never before in his life he was so unhappy. That big is the difference between the celebrated hero for life and the disappointed loser whom no one remembers, only one centimeter. For professional cyclists, it is more preferable to be in the last place than be second. It cannot be worse.

Eddy Plancaert above and Steve Bauer below, Paris Roubaix 1990.
Finish Paris Roubaix 1990
Parijs Roubaix 1990, Eddy Plancaert second.

In 1988 I worked for PDM. I tested there late in the season, a new Norwegian rider who had taken part in the Olympic road race in Atlanta. A small boy who, to my surprise, scored 610 Watts on the ergometer. The best performance in Watts of all time. The second highest score was taken by Australian Phil Anderson a classic specialist. Based on the results we expected a lot of him. But the expectations we had, based on his monster score, he could never fulfill in his career. He was one of the many invisible and anonymous riders in the peloton with no more than one or two victories. Atle Pedersen was the name.

Atle Pedersen
Eddy Planckaert on the right
Peter Post

The lesson we can learn from the test results, of Eddy Planckaert and Atle Pedersen, is that the test results are important but there are other factors that determine whether a rider is a winner. The maximum power or the number of Watts per kilogram that riders score is not everything. Unfortunately, it is a common mistake.

The lactate test is widely used to test riders and provide them with targeted training advice. It is not easy to choose a good protocol for a lactate test. Moreover, it is extremely difficult to interpret the test results in the correct manner. That requires knowledge and experience which is harder than most people realize. Therefore, always perform a lactate test in a modern sports medical laboratory. The data that is gathered at a lactate test are rarely more precise than the data that can be obtained from simple field tests. Although lactate tests may be useful during the pre-season period and for adaptations of the training we usually prefer simple field tests which, with a power meter that can determine the FTP of a cyclist.

When Eddy Planckaert won Paris Roubaix I was team doctor of his team Panasonic. After the race I expected a jubilant mood at the team management but nothing of that.

I even heard from Planckaert that Peter Post, his team manager, did not congratulate him. Late at night I was called at home by Peter Post who tried to make it clear to me, in a very long conversation, that Eddy Planckaert was not the ideal winner for him. Planckaert had a performance contract. He only earned much money as he would win a big race like Paris-Roubaix. Post would have preferred that his highly paid celebrities of his team had won the contest. Which would not have cost him any extra money.