**5. Swimming speeds prescription through a 400 m front** *crawl* **maximum effort (T400)**

Although many distances used in swimming competition does not exceed 2 min (50, 100 and 200 m), the zone related to VO2, commonly referred as aerobic power, is relevant in swimming (Di Prampero 2003), perhaps because T400 is performed in similar SS reach VO2max (Rodrigues 2000). The concept of aerobic power refers to the rate of oxidative energy synthesis (i.e., the maximum power at which the oxidative system can operate, also known as maximum aerobic speed, MAS), available to the muscle work, which can be measured by VO2max. Measuring VO2max in swimming is always a great challenge (PELAYO et al. 2007). This is due to the fact that conventional techniques interfere in swimming biomechanics (Keskinen et al. 2003; Barbosa et al. 2010), which performs the side breathing impossible, changes can occur in hydrodynamics, and most of the times the turns are not performed (Montpetit et al. 1981). Training programs, in order to develop aerobic power in swimmers, are related to the increase in VO2max and the ability to use a high percentage of VO2max for a long time. Maximal aerobic power is widely used to assess aerobic fitness and training intensities prescription (Lavoie & Montpetit 1986).

In an attempt to find alternatives and make the evaluation of athletes swimming closer to reality applied in swimming pools, several studies have been conducted in order to verify the possibility to prescribe training intensities through a single test, but not so extensive such as T30 (Lavoie et al. 1981; Lavoie et al. 1983; Lavoie & Montpetit 1986; Rodrigues 2000; Takahashi et al. 2002; Takahashi et al. 2003, 2009;). The attainment of VO2max values from the

There are gaps in the literature regarding the prediction of Vmax by mathematical models. Billat et al. (2000) found that Vmax3par was not different from the maximum speed obtained in 20 m at maximal effort. However, Bosquet et al. (2006) suggest that Vmax3par is smaller than the real Vmax (obtained by the average speed of the last 10 m of a maximal 40 m effort). Zacca et al. (2010) found that Vmax was higher in sprint than endurance swimmers (2.53 ± 0.15 m·s-1 and 2.07 ± 0.19 m·s-1 respectively) independent of the mathematical model used (three or four parameters). In addition, Vmax4par was greater than Vmax3par (2.42 ± 0.29 m·s-1 and 2.18 ±

The two-parameter model given by the relation "SS-*tlim*" (or *"Dlim*-*tlim*") and three-parameter model given by the relation "SS-*tlim*" have an important limitation: they do not take into account the "aerobic inertia" (τ) (Wilkie 1980; Vandewalle et al. 1989). The "τ" is a temporary delay in VO2 response because of dissociation between O2 absorbed in the lungs and the mainly used by skeletal muscle, lasting approximately 15 to 20 s. "τ" is associated to vasodilatation, i.e, the time it takes for the body to increase heart rate and redirect blood flow. Studies regarding oxygen kinetics during exercise with children and adolescents is limited to few articles and until recently was based on data collected with adults (FAWKNER & ARMSTRONG 2003). Invernizzi et al. (2008) suggest that the time to reach steady state in VO2 after the beginning of the exercise depends on the characteristics of the subject: endurance swimmers reach this balance sooner than sprint swimmers, and children reach earlier than adults. Thus, "τ" could be a good tool for evaluating cardiovascular and pulmonary

**5. Swimming speeds prescription through a 400 m front** *crawl* **maximum** 

Although many distances used in swimming competition does not exceed 2 min (50, 100 and 200 m), the zone related to VO2, commonly referred as aerobic power, is relevant in swimming (Di Prampero 2003), perhaps because T400 is performed in similar SS reach VO2max (Rodrigues 2000). The concept of aerobic power refers to the rate of oxidative energy synthesis (i.e., the maximum power at which the oxidative system can operate, also known as maximum aerobic speed, MAS), available to the muscle work, which can be measured by VO2max. Measuring VO2max in swimming is always a great challenge (PELAYO et al. 2007). This is due to the fact that conventional techniques interfere in swimming biomechanics (Keskinen et al. 2003; Barbosa et al. 2010), which performs the side breathing impossible, changes can occur in hydrodynamics, and most of the times the turns are not performed (Montpetit et al. 1981). Training programs, in order to develop aerobic power in swimmers, are related to the increase in VO2max and the ability to use a high percentage of VO2max for a long time. Maximal aerobic power is widely used to assess aerobic fitness and training intensities prescription (Lavoie & Montpetit 1986). In an attempt to find alternatives and make the evaluation of athletes swimming closer to reality applied in swimming pools, several studies have been conducted in order to verify the possibility to prescribe training intensities through a single test, but not so extensive such as T30 (Lavoie et al. 1981; Lavoie et al. 1983; Lavoie & Montpetit 1986; Rodrigues 2000; Takahashi et al. 2002; Takahashi et al. 2003, 2009;). The attainment of VO2max values from the

0.34m·s-1 respectively), suggesting future studies to compare Vmax and real Vmax.

performance in athletes (Kilding et al. 2006; Duffield et al. 2007).

**4.3.3 Maximum instantaneous velocity**

**4.3.4 Aerobic inertia**

**effort (T400)** 

recovery curve of VO2 (the back extrapolation method proposed by Di Prampero et al. 1976) was first tested on swimmers by Lavoie et al. back in 1983. Lavoie et al. (1983) found a high correlation between VO2max and *tlim* of T400. The possibility to prescribe training intensities using a single test has renewed expectations of swimming coaches and researchers. The attainment of VO2max values trough the back extrapolation involves obtaining VO2 after swimming and applying a simple regression curve between the time and the values of consumption in order to predict the value of VO2 in time zero (Lavoie & Montpetit 1986).

It is believed that the high correlation between VO2max and *tlim* T400 m found by Lavoie et al. (1983) is probably the first indication of the T400 as a non-invasive alternative. Since then, T400 is a reference to verify the MAS and prescribe swimming training intensities (Montpetit et al. 1981; Lavoie et al. 1983; Rodrigues 2000; Pelayo et al. 2007). However, despite many studies reporting the use of T400 by swimming coaches (Wakayoshi et al. 1993b; Dekerle et al. 2005a; Alberty et al. 2006; Dekerle et al. 2006; Pelayo et al. 2007), we did not find a reliable protocol for prescribe more than one swimming training zone through the T400, i.e., a protocol not only able to predict aerobic power, but also another training zone.

By questioning some brazilian coaches, we find that some of them use a protocol (of unknown origin) based on the T400 to monitor and to prescribe three different SS for swimmers and triathletes. Table 2 presents a summary of the equations used to calculate the SS for "aerobic threshold", "anaerobic threshold" and "VO2max".


Table 2. Equations used to calculate the SS for "aerobic threshold", "anaerobic threshold" and "VO2max". K is a constant: K = 0.94 if *tlim* is between 3 min 50 s to 4 min 40 s, K = 0.95 if *tlim* is between 4 min 41 s to 5 min 40 s, K = 0.96 the tlim is between 5 min 41 s to 6 min 40 s, K = 0.97 if *tlim* is above 6 min 41 s, t = time prescribed for a given distance; IVO2 = intensity prescribed to increase VO2max, ILA = intensity for anaerobic threshold and ILAe = intensity prescribed for aerobic threshold.

In this protocol, the coach just needs that your athletes swim 400 m in front *crawl* under maximum intensity (in training situation, but preferably in competitive situation).

Bioenergetics Applied to Swimming: An Ecological Method to Monitor and Prescribe Training 171

based on test performances reflect everything that an athlete recruited to travel any distance

The Cooper test (1968) was based on the linear relationship between running speed and VO2 when, while driving the subject until exhaustion, it was possible to determine VO2max. Billat & Koralsztein (1996) suggest that the accuracy of prediction of VO2max, or also its inaccuracy, depends on the energy cost inter-individual variation, i.e., the total energy expenditure

Daniels et al. (1984) introduced the term "velocity at VO2max" (vVO2max) suggesting that it is a useful variable that combines VO2max and movement economy (Conley & Krähenbühl 1980) on a single factor that identifies aerobic differences among various runners or group of runners. According to Daniels (2005), vVO2max explains individual differences in performance that VO2max or running economy alone could not identify, i.e. individuals with

Daniels et al. (1984) found in female runners who had various combinations of VO2max and running economy (submaximal VO2), that vVO2max was similar to the average speed required to run 3,000 m (maintained approximately for 9 min). In a study with sub-elite distance runners, Billat et al. (1994a) measured a *dlim* at vVO2max of 2,008.7 ± 496 m. However the authors suggest that there is a need to distinguish total run at vVO2max and time run at VO2max race only. Daniels et al. (1984) calculated vVO2max extrapolating through a regression curve relating running speed and VO2. When VO2max was reached, the running speed corresponding to VO2max was identified. Sub-maximal VO2 was calculated from efforts of 6 min at speeds of 230, 248 and 268 m.min-1 at intervals of 4 to 7 min between each effort. VO2max was measured separately in a test based on the incremental pace of 5,000 m, adding 1% for the treadmill speed every minute until the test is terminated, where subjects reported that they would not be able to run more than 30 s. The highest VO2 achieved

For several years, many studies have remained focusing on measuring vVO2max during swimming. However, few investigations in order to determine the tlim-vVO2max were carried out. This training tool which requires the swimmer to keep the exercise intensity corresponding to its vVO2max has been studied mainly by the Billat et al research group. Based on the pioneering work of Hill and Lupton (1923), Billat & Koralsztein (1996) defined this parameter as the maximum time that the vVO2max is maintained until exhaustion (tlim-

The difficulties of measuring VO2 in the aquatic environment hindered the swimming research and related modalities. The first studies were conducted in "swimming flume" (Faina et al. 1997; Demarie et al. 2001). To our knowledge, the first study in the pool, i.e., under normal swimming conditions, was performed by Renoux (2001). However, Renoux (2001) did not present results for cardio respiratory parameters such as VO2 and ventilation. The main results obtained in studies with "swimming flume" suggested that: a) the tlimvVO2max has low inter-individual variability in swimming, unlike other sports such as running (Billat et al. 1994b), and the values are between 4 min 45 s and 6 min 15 s; b) There is an inverse relationship between tlim-vVO2max and vVO2max, similar to running (Billat et al. 1994c); c) There was an inverse relationship between tlim-vVO2max and

in a competitive situation (Daniels, 2005).

required to move the body to a certain distance.

during the maximal test was considered as VO2max.

vVO2max).

anaerobic threshold.

the same VO2max for example, may have different performance times.

*7. tlim* **that swimmers are able to keep at vVO2max (tlim-vVO2max)** 

According to the protocol, the T400 is able to prescribe SS in three different intensities for training in swimming called (1) "aerobic threshold" (ILAE) (2) "anaerobic threshold" (ILA) and (3) "increased VO2max" (IVO2) (Olbrecht 2000; Maglischo 1999). For each intensity, the protocol suggests the time prescription for distances of 50, 100, 200, 400 and 800 m. SS prescribed by T400 for IVO2 is between 94 and 97% from the SS of 400 m (V400). SS prescribed for ILA is proposed as approximately 90% of the V400. SS prescribed for ILAe stands at approximately 84% of the V400.

It can be seen throughout this review that the literature presents a wide naming to explain the [La] response to exercise. However, despite being related to the same phenomenon, the physiological responses are often different, such as LT and MLSS mentioned above, and ILAE and ILA used in this protocol. This means that it cannot be used interchangeably.

As Maglischo (1999) and Olbrecht (2000) suggest, sets on LAE are swum in SS ranging from an intensity which is observed in the first rise in [La] above the resting level to the SS that sits comfortably below the ILA of the swimmer. The total distance can vary between 2,000 and 10,000 m for adult swimmers or 20 to 120 min for young swimmers. Any distance can be used in the interval sets. Regarding the rest intervals between each repetition, it is suggested 5 to 30 s (Olbrecht 2000). Still, in ILA sets, the total distance of the set can range from 2,000 to 4,000 m for adults, or approximately 30 min for younger athletes (Maglischo 1999; Olbrecht 2000). Distances between 25 and 4,000 m can be used in the interval sets (Maglischo 1999; Olbrecht 2000), with rest intervals between 10 to 30 s (Olbrecht 2000). Series aimed to increase VO2max, Maglischo (1999) suggests SS slightly above the ILA until 95% of best performance (Maglischo 1999) (Severe intensity domain). It is suggested distances between 25 to 2.000 m, with intervals of rest of 30 s to 120 s between each repetition (Maglischo 1999). However, the SS percentage suggested for training zones prescription have not been observed in constant speed tests until exhaustion. However, similarities were observed in *tlim* and percentage of training zones prescription between the T400 and the 1 mile running applied by Daniels (2005). Daniels's concepts (Daniels 2005) were based on "velocity at VO2max" (vVO2max).

#### **6. Velocity at VO2max (vVO2max)**

Although VO2max is accepted as the physiological variable that best describes cardiovascular and respiratory capacities (Hill & Lupton 1923; Billat & Koralsztein 1996), vVO2max was measured only five decades later in order to provide a practical method to measure aerobic fitness in runners (Billat & Koralsztein 1996). In the 80's there was a growth interest in the physiological assessments in order to monitor athletic training (Billat & Koralsztein 1996). However, it is known that protocols for VO2max measurement, for example, require trained professionals, special equipment and need to be conducted in a controlled environment.

The first field test used to measure vVO2max was intended to replace the 12 min test Cooper (Cooper 1968) as an alternative to predict VO2max in a unique effort to simplify procedures and reduce costs. Cooper (1968) reported a correlation of 0.9 between VO2max and the distance covered in a 12 min test running or walking. However, the motivation and rhythm was mentioned as critical to achieve good reliability in a 12 min test (Cooper 1968). Importantly, when prescribing training intensities based on the performance test, is also considered the psychological characteristic of the race, because instead of applying laboratory tests to monitor training status of the athlete, we use the performance obtained in competitive events, which is directly affected by the willingness to deal as discomfort. Tests

According to the protocol, the T400 is able to prescribe SS in three different intensities for training in swimming called (1) "aerobic threshold" (ILAE) (2) "anaerobic threshold" (ILA) and (3) "increased VO2max" (IVO2) (Olbrecht 2000; Maglischo 1999). For each intensity, the protocol suggests the time prescription for distances of 50, 100, 200, 400 and 800 m. SS prescribed by T400 for IVO2 is between 94 and 97% from the SS of 400 m (V400). SS prescribed for ILA is proposed as approximately 90% of the V400. SS prescribed for ILAe stands at

It can be seen throughout this review that the literature presents a wide naming to explain the [La] response to exercise. However, despite being related to the same phenomenon, the physiological responses are often different, such as LT and MLSS mentioned above, and ILAE

As Maglischo (1999) and Olbrecht (2000) suggest, sets on LAE are swum in SS ranging from an intensity which is observed in the first rise in [La] above the resting level to the SS that sits comfortably below the ILA of the swimmer. The total distance can vary between 2,000 and 10,000 m for adult swimmers or 20 to 120 min for young swimmers. Any distance can be used in the interval sets. Regarding the rest intervals between each repetition, it is suggested 5 to 30 s (Olbrecht 2000). Still, in ILA sets, the total distance of the set can range from 2,000 to 4,000 m for adults, or approximately 30 min for younger athletes (Maglischo 1999; Olbrecht 2000). Distances between 25 and 4,000 m can be used in the interval sets (Maglischo 1999; Olbrecht 2000), with rest intervals between 10 to 30 s (Olbrecht 2000). Series aimed to increase VO2max, Maglischo (1999) suggests SS slightly above the ILA until 95% of best performance (Maglischo 1999) (Severe intensity domain). It is suggested distances between 25 to 2.000 m, with intervals of rest of 30 s to 120 s between each repetition (Maglischo 1999). However, the SS percentage suggested for training zones prescription have not been observed in constant speed tests until exhaustion. However, similarities were observed in *tlim* and percentage of training zones prescription between the T400 and the 1 mile running applied by Daniels (2005). Daniels's concepts (Daniels 2005)

Although VO2max is accepted as the physiological variable that best describes cardiovascular and respiratory capacities (Hill & Lupton 1923; Billat & Koralsztein 1996), vVO2max was measured only five decades later in order to provide a practical method to measure aerobic fitness in runners (Billat & Koralsztein 1996). In the 80's there was a growth interest in the physiological assessments in order to monitor athletic training (Billat & Koralsztein 1996). However, it is known that protocols for VO2max measurement, for example, require trained professionals, special equipment and need to be conducted in a controlled environment. The first field test used to measure vVO2max was intended to replace the 12 min test Cooper (Cooper 1968) as an alternative to predict VO2max in a unique effort to simplify procedures and reduce costs. Cooper (1968) reported a correlation of 0.9 between VO2max and the distance covered in a 12 min test running or walking. However, the motivation and rhythm was mentioned as critical to achieve good reliability in a 12 min test (Cooper 1968). Importantly, when prescribing training intensities based on the performance test, is also considered the psychological characteristic of the race, because instead of applying laboratory tests to monitor training status of the athlete, we use the performance obtained in competitive events, which is directly affected by the willingness to deal as discomfort. Tests

and ILA used in this protocol. This means that it cannot be used interchangeably.

approximately 84% of the V400.

were based on "velocity at VO2max" (vVO2max).

**6. Velocity at VO2max (vVO2max)** 

based on test performances reflect everything that an athlete recruited to travel any distance in a competitive situation (Daniels, 2005).

The Cooper test (1968) was based on the linear relationship between running speed and VO2 when, while driving the subject until exhaustion, it was possible to determine VO2max. Billat & Koralsztein (1996) suggest that the accuracy of prediction of VO2max, or also its inaccuracy, depends on the energy cost inter-individual variation, i.e., the total energy expenditure required to move the body to a certain distance.

Daniels et al. (1984) introduced the term "velocity at VO2max" (vVO2max) suggesting that it is a useful variable that combines VO2max and movement economy (Conley & Krähenbühl 1980) on a single factor that identifies aerobic differences among various runners or group of runners. According to Daniels (2005), vVO2max explains individual differences in performance that VO2max or running economy alone could not identify, i.e. individuals with the same VO2max for example, may have different performance times.

Daniels et al. (1984) found in female runners who had various combinations of VO2max and running economy (submaximal VO2), that vVO2max was similar to the average speed required to run 3,000 m (maintained approximately for 9 min). In a study with sub-elite distance runners, Billat et al. (1994a) measured a *dlim* at vVO2max of 2,008.7 ± 496 m. However the authors suggest that there is a need to distinguish total run at vVO2max and time run at VO2max race only. Daniels et al. (1984) calculated vVO2max extrapolating through a regression curve relating running speed and VO2. When VO2max was reached, the running speed corresponding to VO2max was identified. Sub-maximal VO2 was calculated from efforts of 6 min at speeds of 230, 248 and 268 m.min-1 at intervals of 4 to 7 min between each effort. VO2max was measured separately in a test based on the incremental pace of 5,000 m, adding 1% for the treadmill speed every minute until the test is terminated, where subjects reported that they would not be able to run more than 30 s. The highest VO2 achieved during the maximal test was considered as VO2max.
