Training of rowers before world championships

Abstract

Training of rowers before world championships. Med. Sci. Sports Exerc., Vol. 30, No. 7, pp. 1158-1163, 1998. In rowing, static and dynamic work of approximately 70% of the body's muscle mass is involved for 5.5 to 8 min at an average power of 450 to 550 W. In high load training phases before World Championships, training volume reaches 190 min·d⁻¹, of which between 55 and 65% is performed as rowing, and the rest is nonspecific training like gymnastics and stretching and semispecific training like power training. Rowing training is mainly performed as endurance training, rowing 120 to 150 km or 12 h·wk⁻¹. Rowing at higher intensities is performed between 4 and 10% of the total rowed time. The increase in training volume during the last years of about 20% was mainly reached by increasing nonspecific and semispecific training. The critical borderline to long-term overtraining in adapted athletes seems to be 2 to 3 wk of intensified prolonged training of about 3 h·d⁻¹. Sufficient regeneration is required to avoid overtraining syndrome. The training principles of cross training, alternating hard and easy training days, and rest days reduce the risk of an overtraining syndrome in rowers.

Rowing is a sport in which about 70% of the whole body muscle mass is involved. The energy expenditure of rowing a race is very high. The power per stroke is between 800 and 1200 W at the start and 600 and 900 W during the race, which amounts to an average power of 450 to 550 W during the 5.5 to 8 min of a race ^(30,34). Therefore, anaerobic alactic and lactic as well as aerobic capacities are stressed to their maximum ⁽²⁸⁾. Rowing is therefore an ideal model to study training effects.

There is no common theory of training processes that describes the type, the quantity, or the pattern of a certain training stimulus or a particular training program, which is necessary to achieve a given performance response for an athlete. The main knowledge is basically empiric ^(1,2,17,31). However, there is consensus that training and performance are related by a dose-response relationship ^(2,29,34). Uncertainty about the trainability at a given level of performance will often lead to 1. inappropriate training response of the athlete and insufficient competition results or 2. overreaching and in the long term staleness, burnout syndrome, or overtraining syndrome ^(4,18,20).

Many published data are obtained from athletes of college or of lower athletic levels, and they might not be applicable to more capable athletes that are potential members of national teams. Therefore, this review deals with the training load that can be achieved, the published training schedules, and the responses in performance and metabolic parameters and hormones in high level rowers participating in World Championships.

ORGANIZING OF TRAINING SCHEDULES

Periodization of training, macrocycles and microcycles. A training stimulus, which is referred as a single training unit of exercise or other tasks, will generate a response of the trained system if the stimulus is high enough. Repetition of the same stimulus will result in a smaller response, and after repeated training stimuli, responses will reach asymptotically a limit. By increasing the intensity and duration of a training unit or by increasing the number of training units, further increases in performance can be reached. Increases in training load will increase the need for recovery and regeneration. Therefore, training has to be organized in phases of training with high load to induce a training response and phases of lower load to allow recovery. The structure of training is commonly organized in mesocycles of 1 wk duration. These mesocycles are part of a whole macrocycle, which is usually between 6 and 12 months. Such macrocycles are demonstrated in Figures 1 and 2 for the preparation of the Dutch Female National Team for the 1988 Olympic Games ^(38,39) and for the Norwegian and Danish Rowing Teams for World Championships ⁽³⁰⁾.

Figure 1: Seasonal Training volume (totmin) per day for the period preceding each test number, and the mean minutes of rowing (romin) and of land training (lamin) per day in six female members of the Dutch National Team (tests 1, December; 2, January; 3-5, February; 6-10, March to August in approximately 4 wk distance). Data are from Vermulst et al. ⁽³⁸⁾ with permission.

Figure 2: NOR) and Danish (DAN) oarsmen during a summer of training associated with their training protocol. The Norwegian group emphasized endurance training and showed improvement in both power and maximal uptake. A decrease of V˙O_2max was found in the Danish group when total training volume decreased between weeks 26 and 33. Data are from Secher ⁽³⁰⁾ with permission.

For rowers, it has been demonstrated that the trained kilometers are positively related to the success in championships ^{(15,17,23,25,34)}, but the risk of overtraining increases with daily training time and particular monotonic training ^(4,7,9,18). This was particularly true in the late 70s, when some eastern teams trained more than 6 h·d⁻¹ on the water with very low intensities. Use of various training methods ^(1,2,17), cross training ⁽⁸⁾, concentration on certain training stimuli, variation of training load by short time overloading, and following regeneration, may further increase performance ^(1,34). This means two or three mesocycles are followed by one or two recovery mesocycles.

A microcycle in rowing will also be structured in days of high load and lower load. In high level athletes, there will be alternated 1 to 2 "hard" days with 1 "easy" day, which means that after 3 and 5 training units, the next training unit will be off.

Complexity of training goals. Another problem of studying training effects is the complexity of the goals of training because different capacities of the athlete have to be developed and improved. As a typical middle time power endurance sport, rowers need physical power to achieve a high power per stroke, endurance to sustain this power for 2000 m, which means 5.5 to 8 min depending on the type of boat, special motor skills, tactical skills, and, very importantly, motivation and drive for success ^{(11,12,25,27)}. This complexity causes timing problems because some training goals cannot be achieved together. For example, endurance and sprint training are not considered compatible in a training session. Therefore, sophisticated and often complex training schedules have to be used that take into account physical capacities of athletes and the time for training and regeneration ^(13,24,31).

Over the year, the percentage of specific rowing training on the water is 52 to 55% for the 18-yr-old, 55 to 60% for the 21-yr-old, and up to 65% for the older athlete. Power training is in the range from 20% at 18 yr and 16% at the adult athlete, and general athletic training is in the range from 26 to 23%, respectively ⁽¹⁾. This means more specific (rowing) training with increased training experience.

TRAINING BEFORE WORLD CHAMPIONSHIPS

Rowing training and cross training (Dutch, Norwegian, Danish, and German experiences). Training schedules have been documented only in few studies ^{(13,15,24,25,30,35)}. It is interesting that in the preparation for the 1988 Olympics, female rowers of the Dutch National Team seldom reached training volumes of 200 min·d⁻¹. Training volume averaged approximately 80 min ⁽³⁹⁾. This volume seems very low for successful rowers because there should be only a small difference between the training volumes of female and male rowers ^(17,24). However, in high level athletes, Serup et al. reported an average rowing volume of approximately 160 km·wk⁻¹, which corresponds to about 12 and 14 h of rowing per week or 115 min·d^−1(30,31).

In the 1995 German Junior National Team, training load reached 190 min·d⁻¹ in the high load phases, and was as high as 108 and 132 min in the tapering phases before and after the high load phase (Fig. 3). Why should Juniors be able to train more than Seniors? The real reasons are in the unpublished data. It is clearly depicted in Figure 3 that in the high load phases 1 and 2 training consisted of approximately 55% rowing at intensities below lactates of 4 mmol·L⁻¹, 4% of high intensity rowing but approximately 38% of land training. A rowing time of 59% equals to 112 min (or 23 km·d⁻¹), which now easily fits to the previously published data ^(30,31). This means that in 1995, Juniors trained as much as Seniors in 1990. This progress in training loads is more impressive comparing the load reported here with approximately 150 min total training time, which found 1989 in the same German National Junior Rowing Team ⁽³⁵⁾. In 1989, in the high load phase, 128 min·d⁻¹ were rowed ⁽³⁵⁾ plus approximately 22 min of unspecific regenerative training; in the low load phase, the numbers were 98 and 20 min, respectively. That means total rowing training volume has nearly not changed or was slightly decreased. The 22% increase in total work time comparing the high load phases of 1989 and 1995 is mainly the result of intensive semispecific training.

Figure 3

Maximum sustainable training load. Does training load mean improvement of performance? A decrease in performance was observed after 7 to 10 successive days of unaccustomed prolonged training in nonathletic subjects ^(7,9). In athletes, performance decreased after 10 d of intensified swimming training in elite swimmers ⁽⁵⁾ and after 14 d of intensive training in cyclists but was accompanied by supercompensation after 1 to 2 wk of recovery ⁽¹⁴⁾. Increases in training volume are generally considered to be more critical than increases in training intensity ^(9,10,20,21).

The question of how long overreaching can be extended for maximum increase in performance in athletes can be addressed by the data presented here. In Figure 4, changes in performance at 4 mmol·L⁻¹ lactate and maximum performance are depicted for the German Junior Team in 1995 from phase 0 to the beginning of the tapering phase (phase 3). During overreaching periods, power at 4 mmol·L⁻¹ lactate often decreases, but maximum performance is maintained (Fig. 4, left and middle columns). The tapering phase results in a further increase in performance, which is demonstrated as an increased velocity of the boats (Fig. 4, right column). These data reveal that for these athletes overloading in training phases 1 and 2 was compensatory, and the training goals were achieved.

Figure 4: Changes in power at 4.0 mmol·L⁻¹ lactate (left column) and maximum performance (P_max, middle column) in an incremental rowing ergometer test for all boats of the German Junior National Team (test 1, phase 0; test 2, start of phase 3; see Fig. 3). The change in competition time is depicted in the right column together with the medals gained.

These increases in performance capacity can only be analyzed in "all-out" rowing or rowing ergometer tests. Therefore, we regularly perform incremental stage tests up to exhaustion. The maximum oxygen uptake (V˙O_2max) has the best predictive value for competitive results (at a given rowing efficiency) ^{(11, 30, 34)}. The V˙O_2max increases with training distance per year but levels off at training volumes of approximately 5000 to 6000 km·y^{−1(17,29,34)}. Seasonal changes have been described in V˙O_2max, which are between 5 and 20 mL·min⁻¹·kg⁻¹ during the competition season ^{(13,25,30,34)}. V˙O_2max decreases in highly trained athletes when the weekly rowed distance is reduced below approximately 100 km·wk^−1(25,34). Therefore, the decrease in V˙O_2max in the Danish rowers in weeks 26 and 33 of their training is explainable because the rowed kilometers decreased compared with the Norwegian group (Fig. 2). Despite the value of V˙O_2max, the measurement has considerable costs and needs laboratory and personal capacities and time. Therefore, often the maximum performance (P_max) in a standardized test is used for evaluation of the·exercise capacity ^{(11,12,23,27,33)}. However, P_max is subject to motivation of the rower tested (which is depicted by the sharp decrease in P_max in the JM 2× despite good race time in Fig. 4) and may not be sensitive enough for monitoring a complete rowing season ⁽³⁴⁾.

Endurance capacity is an important result of training. Higher performance at the lactic threshold (LAT, 4 mmol·L⁻¹ lactate) means higher maximum performance (Fig. 5a), but there is a wide scatter in the individual data. On average, LAT is 75 to 85% of P_max(Fig. 5a). With a higher percentage of ST fibers, rowers are able to perform with more power per stroke at a blood lactate concentration of 4 mmol·L^−1(13,28). Specific endurance training increases the work per stroke at the same lactate level; this may be caused by ST fiber content but also by increased oxidative capacities of FT fibers (type IIa fibers) ⁽²⁸⁾. The maximal blood lactate concentration after exhausting rowing decreases with higher LAT (and oxidative fiber content) owing to lower glycolytic capacities (Fig. 5b). Lower glycolytic capacities may be of negative effect at the start spurt and the final spurt in the rowing race ⁽²⁷⁾. In the rowers presented in Figure 4, maximum lactate concentrations were nearly unchanged in the second test. Training and conditions before the test should be standardized to avoid depletion of glycogen stores ^(5,22,32), which may influence interpretation of the lactate-performance curves. These curves are important for the analysis of sport-specific endurance ^(26,29,34).

Figure 5: a. Maximum performance versus lactic anaerobic threshold (LAT, power at 4 mmol·L⁻¹ lactate) (left panel) in the incremental rowing ergometer test (N = 59, P_max = 0.43 * LAT + 320, r = 0.64). b. Maximum lactate versus lactic anaerobic threshold (LAT, power at 4 mmol·L⁻¹ lactate) (right panel) in the incremental rowing ergometer test (N = 58, La_max = −0.06 LAT + 38.0, r = 0.69).

Specific and unspecific training. What is the reason that the maximum rowed kilometers are averaging approximately 23 km or 115 min·d⁻¹? Mader and Hollmann pointed out that the reason may be mainly energetic because energy input has to equal energy consumption ⁽²³⁾. If a highly trained rower (V˙O_2max, 6.0 L·min⁻¹) trains at the LAT (75% of V˙O_2max), this means an actual V˙O₂ of 4.5 L·min⁻¹, which is 1350 kcal·h⁻¹. If the average calorie intake of a rower is assumed to be approximately 6000 kcal·d⁻¹, this means approximately 4200 kcal usable for training, or 3.1 h of training. Reducing intensity, the energy consumption increases the maximum tolerated training time. Increasing training intensity limits the sustainable training volume. In rowing, energy consumption increases with the third (3.2) power of boat speed ^(6,30), which means high boat speeds require high V˙O₂. However, the net efficiency of rowing is approximately 0.25, which is better than that of ergometer rowing (0.18-0.22), and there is lower lactate accumulation at a given V˙O₂ compared with ergometer rowing, which indicates lower contribution of fast anaerobic fibers to rowing in boat ^{(12,28,33,35)}.

If endurance training, which remains the most important part of the rower's training schedule ^{(1,14,15,30,31)}, seems to be limited by energy balance, why should unspecific and cross training increase training tolerance? A similar effect of training volume can be seen in an increased risk of overtraining by increasing training volume in other kinds of sports ^{(7,8,18,19,21)}. In cross training, different muscle groups are recruited, which may allow partial recovery of other muscle groups. Therefore, the advantages of cross training seem to be "peripheral" effects, enhancing or maintaining strength in power training, without depleting energy stores and local muscle glycogen, and "central" effects by decreasing the monotony of training ^(8,21,34). However, semispecific power training elicits high lactate concentrations that are in the range of intensive rowing (refs. ^{14 and 30}; Table 1). Nonspecific (and low intensity) training is "active regeneration" and enhances recovery from strenuous workouts ⁽¹⁾, mainly by increased peripheral blood flow. Gymnastics and stretching restore especially flexibility and decrease tension of the muscles ⁽³⁶⁾. Sufficient energy intake for restoration of energy stores, especially of muscle glycogen, is very important for the elite rower ^(17,23,31). Therefore, a high carbohydrate intake was correlated with better improvement of work capacity versus normal diets ⁽³²⁾.

TABLE 1

Biochemical and hormonal indices of overloading. Despite high training loads, in several studies of rowers, only a relatively small magnitude of changes in biochemical and hormonal variables was found ^{(34,35,37,39)}. In high load training phases, decreases of peripheral steroid hormones, e.g. free testosterone and cortisol, were consistently observed in rowing, as in other endurance sports ^{(7,19,21,35,37,40)}. Until now, there are no data demonstrating that the central endocrine hypothalamic-pituitary regulation is depressed in high load training phases in rowers ^(3,4,20).

In the tapering phase, peripheral steroid hormones increase again. These changes are physiological in part of the response to training ^{(10,18,21,38)}. The free testosterone to cortisol ratio has no practical value for the diagnosis of overloading and overtraining, as previously discussed ^(35,39).

Creatine kinase reflects training intensity and muscular strain only at the beginning of a training phase, decreasing CK levels and suggesting muscular adaptation to training ^(34-36). Urea has only minor value because it is influenced by hydration, nutrition, and protein catabolism ^(34,36,37). Hematocrite may be monitored as a simple measure of hydration of the rowers ⁽³⁶⁾. Psychological questionnaires may be of practical value in diagnosis of overload situations ⁽³⁶⁾.

CONCLUSION

This review confirms that the critical borderline to long-term overtraining in adapted endurance athletes seems to be 2 and 3 wk of intensified prolonged training of about 3 h·d⁻¹. Sufficient regeneration is required to avoid overtraining syndrome. The training principles of cross training, alternating hard and easy training days, and resting days reduce the risk of an overtraining syndrome in rowers.