Physiological characteristics and performance of the white-water paddler

Europ. J. appl. Physiol. 32, 55--70 (1973) �9 by Springer-Verlag t973

Physiological Characteristics and Performance of the White-Water Paddler

K. Sidney and R o y J . Shephard

Dept. of Environmental Health, School of Hygiene, University of Toronto

Received April 30, t973

Abstract. Tests have been completed on t0 men and 2 women, all aspirant members of the Canadian national white-water team. Objective scores account for some 75 % of the variation in ability noted by the team coach, and can provide (i) a useful counterweight to errors of judgement by the coach, and (ii) indications for an individualized training programme. The successful white-water paddler is characterized by many years of experience, a substantial standing height and lean body mass, good general mnscle development with particular emphasis on the leg muscles, a good but not outstanding aerobic power, an above-average vital capacity, and tolerance of a large oxygen debt; control of body fat does not seem particularly vital to success. The maximum heart rate and the parameters of the recovery curve seem as in the normal population; however, a single Astrand nomograr~ prediction does not provide adequate information on the aerobic power of the individnal athlete.

Key words: Canoeing -- Kayaks -- White-Water Paddling -- Aerobic Power -- 1V[aximum Oxygen Intake -- Oxygen Debt -- Performance Predictions.

Introduction The canoeing exploits of the v o y a g e u x occupy an impor tan t place

in Nor th American his tory; the I-Iowells [9] provide a fascinating glimpse of canoe races between the Indians and the early settlers of this continent. A s t rong intexest in recreational canoeing has persisted in Canada; Olympic medals were won by the Canadian canoe teams in t936 and t948, and an Ot tawa rega t ta in 1950 repor ted over 500 entrants . However, a poor performance in the t952 Olympics heralded a decline of formal sport, and in recent years serious racing has been infrequent. The white-water slalom, in particular, became an obscure regional event, and internat ional compet i t ion was a lmost unknown until interest was revived by its inclusion for the first t ime in the Munich Olympic contes~ (t972).

There are two principal classes of slalom race. I n the K or k a y a k class, a single compet i tor sits with his knees flexed by about 30 ~ and paddles with a double-ended blade. I n the C or canoeing class, one (CI) or two (CII) compet i tors kneel in the boat , paddl ing with single-ended blades. The boats for bo th classes of competi t ion are ~3 to ] 5 feet long,

56 K. Sidney and Roy J. Shephard

and are typically made of fibre glass, with the bow and stern sections completely enclosed. The rules require the competitor to paddle as rapidly as possible over a 400 to 800 m course that passes through some two dozen gates situated in rough and rapidly flowing water (the current on the local Credit river course commonly averages i2 to i4 miles/h). Changes in water speed and direction on an international course are so quick and unpredictable tha t one contestant likens the exercise to paddling in a giant washing machine. The paddler's score is computed from a combination of elapsed time and penalties (10 to i5 see each) awarded for hitting or missing gates.

Perhaps because white-water racing is an obscure sport, there has been no previous investigation of the characteristics of the successful paddler. The cumulative abstracts of the American Association for Physi- cal Health, Education and Recreation (1959 to i972) have listed but five papers on canoeing. Two deal with teaching techniques, one with the design of a film strip, one with the history of canoeing in Minnesota, and one with opportunities for white-water paddling in California. Ishiko [10] found the score of smooth-water canoeists on the Harvard Fitness test was equal to tha t of bicyclists, but inferior to tha t of mara- thon runners and pentathlon contestants. Saltin and Astrand [13] reported that four members of the Swedish National Canoe team had an average aerobic power of 70 ml/kg/min. Cumming [5] tested a less selected group of l0 male and 7 female canoeists, finding hand-grip strengths averaging 55.t and 37.6kg respectively, with an aerobic power of 51.8 ml/kg/min in two male contestants. An early report from Berlin [2i] set the caloric cost of eannoeing at the very low level of 3 to 7 kCal/min; however, speeds were recreational rather than compe- titive (2.5 to 4.0 m.p.h.). More recently, Seliger [t4] noted an average energy expenditure of 10 kCal/min in 16 young paddlers, with a peak heart rate of 149/rain, and an average of 136/min.

None of the reports cited refer specifically to white-water contestants, although it is recognized that some athletes participate in both smooth and white-water contests. Accordingly, we judge it worthwhile to report information on i0 male and 2 female white-water contestants, all aspirants to the Canadian national team. Structural and functional variables are described, and the features of the successful contestant are delineated.

Methods Subjects and Experimental Plan. The subjects were aspirants to the

Canadian national white-water team drawn from the main white-water clubs in the Toronto region. Scores for an 800 m' national competition (Table i) show a fair range of ability. Three contestants (Pc, Ke and Mu) were selected to represent Canada at Munich. Of the ten men, seven

The White-Water Paddler 57

Table 1. Standing of constants in 1971 Canadian National Slalom championships (800m' course and Munich Olympics 600m' course)

t971 National championship

Class and course Contestant Score (sec)~

K-I Ke 325.4 Po 362.6 MeC 465.0 He 490.4

K-I Jr ~u 428.0

K-I W Pa 723.5 tto 850.0

C-I Tw 683.4

C-I Jr Ho 856.8 Ha 895.0 McK 901.7

C-II Jo 628.8 (two contestants)

t972 Olympic contest Time (see) Penalty (sec) Score (sec)~

Winner 258.6 l0 268.6 1/37 Mu 304.8 130 434A 34/37 Po 309.9 160 469.9

3i9.3 140 459.3 35/37

Ke 290.5 350 650.5 305.5 290 595.5 37/37

Including penalty points.

were relatively young, but three with accumulated experience and skills were much older. The two female contestants were quite young. Physical characteristics are summarized in Table 2.

Subjects reported to the test laboratory at 7:30 a.m., having last eaten at 9:00 p.m. the previous evening. They were iustructed to take at least 8 h sleep, and to avoid unnecessary activity en route to the laboratory. None of the group smoked or drank alcohol. Two laboratory attendances were scheduled. At the first visit, body weight, height, skinfold thicknesses, lung volumes, and muscle strength were measured, and a standard sub-maximal treadmill run was performed. No "habitua- t ion" was necessary, as all subjects were using the treadmill as part of their daily training circuit. At the second visit, two mornings later, a maximum treadmill test was carried out. Unless noted otherwise, the methodology standardized for the International Biological Programme [20] was used throughout.


Table 2. Physical characteristics of white-water paddlers. Mean + S.D,, range of data

Age Height Weight Body Racing (yr) (era) (kg) surface experience

areas (years) (m~)

Young t8.7 + 2.0 173 _~ 4 64.0 + 5.4 t.77 _+ 0.09 3--5 males ( 1 7 - - 2 2 ) (166--180) (55.8--71.3) (1.62-- 1.89) (n = 7) Older males 33.0 180 79.2 t.99 2--14 (n = 3) ( 28 - -37 ) (t75--t89) (72.6--86.4) (1.88--2.13) Females 18.0 166 57.3 t.63 4, 7 (n = 2) (i7, i9) (16t, t72) (51.7, 62.8) (t.52, t.74)

Calculated according to the DuBois nomogram.

Skinfold Thicknesses. Skinfold thicknesses were measured at eight standard sites (triceps, subscapular, suprailiac, chest, chin, waist, suprapubic, and knee) using Lange calipers (Cambridge Instrument Co., Cambridge, Md.). The percentage of body fat was estimated from the summed skinfold readings (E 2 [triceps] + subscapular + suprailiae), using the conversion table of DurnJn and Ramahan [7] 1.

Muscle Strength. Right and left grip were measured by Stoelting dynamometer, the reported result being the best of three definitive attempts with each hand. A cable tensiometer [4] was used to measure the maximum force of knee extension ( i i5 ~ extension), elbow flexion (90~ trunk flexion and trunk extension. Again, the highest ofthreedefin- itive readings was taken.

Lung Volumes. The forced vital capacity (F.V.C.) and I see forced expiratory volume (F.E.V.1.0) were determined in the standing position, using a Stead-Wells spirometer. Reported results are the average of at least two satisfactory definitive attempts. Predicted normal values were calculated according to the equations of Anderson et al. [i] and Miller et al. [ i i] .

Sub-Maximal Treadmill Test. In both sub-maximum and maximum tests, the electrocardiogram was monitored continuously, using C~ 5 leads. The heart rate was calculated from the e.c.g, record at i rain intervals. Oxygen consumption was measured by standard open- circuit techniques, using an Otis-McKerrow valve box, a short length of broad-bore tubing and meterological balloons. Gas samples were taken into well-oiled glass syringes and analysed by physical methods (an infra-red analyser for carbon dioxide and a paramagnetie analyser for

1 The original formulation is for Z triceps + biceps + subscapular + suprailiac.


oxygen). The expired volumes were determined by transferring the contents of the balloons to a Tissot spirometer.

Resting oxygen consumption and heart rate were determined over a i0 rain sitting period. Subjects then ran at a treadmill speed of 6 miles/h, with 3 min at each of three increasing slopes (2, 4, and 6 %)2, corresponding to approximately 65, 75 and 85 % of aerobic power. Oxygen consumption was measured in the final 1/~ min at each slope, and the maximum oxygen intake was predicted from the corresponding pulse rate, using a computer solution [f6] of the Astrand nomogram [3]. Ten further samples of expired gas were collected during the recovery period (0 to 1/2, 1/~toi, i t o 2 , 2 t o 3 , 3 t o 4 , 4 t o 6 , 6 t o 8 , 8 to i0, i0 to i2, and 12 to i5 rain).

Maximal Exercise. The treadmill speed and slope needed to induce a maximum oxygen consumption was calculated from the predicted aerobic power as estimated in the sub-maximal test, using a simple nomogram [15]. As in the submaximumtest , the maximum test commenc- ed with 3 rain of effort at 65 % of aerobic power and proceeded through two further 3 rain stages at 75 and 85 % of aerobic power. The slope of the treadmill was then increased to the predicted maximum effort and was further increased by I to 2% at 2 rain intervals thereafter until signs of a centrally limited [i7] maximum oxygen intake were noted. Expired gas was collected in the final 1/u rain at each loading, and a further ten bags were collected in the recovery period, as in the sub- maximal test.

Arterialized capillary blood was collected from the heated finger tip 2 min after ceasing exercise. Blood lactate concentrations were determined by a micro-enzymatic method [12, i7].

Coach's Assessment. The team coach was asked to rate the athletes on skill, power, endurance, and overall ability prior to receiving the laboratory reports.

Results

Physical Characteristics. The height of the young males was not remarkable (Table 2); however, the three older males (presumably "self-selected" by their success in the sport) and the two girls were of above-average height. The coefficient of correlation between the coach's rating of overall ability and standing height for the men was -~ 0.57 + 0.29.

The young males were relatively light (on average, 3.8 kg less than the "ideal" weight predicted from the tables of the Society of Actuaries [i9]). On the other hand, the older men and the girls each carried a substantial excess weight (5.8, 9.5 kg respectively). This was attributable more to muscle than body fat (Table 3), and contributed substantially to

2 In the two female subjects, slopes of 0, 2 and 4 % and 2, 4 and 5 % were used.


Table 3. Thickness of skinfolds, relative to values for men and women of "ideal" body weight,. Mean + S.D., range

Young males Older males Ideal Females Ideal (n = 7) (n = 3) male s (n = 2) females

Triceps ~ 5.9 _+ 1.5 7.7 7.8 10.5 15.6 (5.0- 9.0) (4.0-- t0.0) (9.5, 11.5)

Subscapularb 7.4 + 1.5 12.2 t t .9 9.0 11.3 (5.5- t0.0) (10.0- t6.0) (7.0, 11.0)

Suprailiac b 6.4 +_ 1.4 9.7 t2.7 8.5 14.6 (4.5 - 9.0) (5.0- 15.0) (6.0, 11.0)

Chin 3.8 + 0.5) 9.0 5.8 6.5 7.1 (3.5 - 4.0) (4.5 - t2.0) (5.0, 8.0)

Chest 5.9 _+ t.4 10.8 12.0 6.5 8.6 (3,5 - 7.5) (9.0 - t2.0) (6.0, 7.0)

Waist 4.4 +_ 0.8 7.5 14.3 7.0 i5.3 (3.0 - 5 .0) (4.5 - 11.5) (5.5, 8.5)

Suprapubic 6.1 _+ t.3 10.8 11.0 9.8 20.5 (3.5 - 7.0) (9.5- 12.0) (9.0, 10.5)

Knee 6.9 + 2.0 7.3 8.6 16.5 1t.8 (5.0- 10.5) (6.0- 9.5) (13.5, 19.5)

Total, 3 folds b t9.7 29.6 32.4 28.0 41.5 8 folds 46.8 75.0 84.t 74.3 104.8

% Fat (Durnin) 11.6 _+ 1.7 15.7 17.0 23.8 29.4 (10 - 15) (11 - 20) (2t.8, 26.0)

Authors' data. b Three folds recommended to International Biological Programme.

performance. Comput ing lean b o d y mass (LBM), the correlation between overall abil i ty and L.B.M. was 0.72 + 0.24.

The thickness of sub-cutaneous fat m a y be related (i) to the readings obtained in subjects of " ideal" weight, and (ii) to norms proposed for the college-age popula t ion b y Yuhasz [22]. I n the young men, readings averaged 55 % of those found in a m a n of " ideal" weight, emphasizing t h a t the actuarial s tandard sets an upper l imit compatible with sedentary health. The two young girls also had much less subcutaneous fat than the " ideal" woman in every region except the knee; it is interesting to speculate whether the fat accumulat ion in this region m a y reflect the relative immobi l i ty of the knees during canoeing. One of the older men (Po) had a substant ial thickness of sub-cutaneous fat ; he also received the highest ra t ing f rom the coach.

Yuhasz [22] quotes an average to ta l of 30.8 m m for the three I .B.P . skin folds in the college male, and suggests t h a t an op t imum appearance

The White-Water Paddler

Table 4. Isometric muscular force (kg). Mean _+ S.D., range. Norms from Asmussen et al. [2], Howell et al. [:19], and Yuhasz [20]

6t

Young males Older males Norm Females Norm ( n = 7 ) ( n = 3 ) A :K Y ( n = 2 ) A H Y

Handgrip 1% 52.0• 56.0 44 37 56 31.0 28 29 35

(30 - 61) (51 - 61) (30, 32) L 50.0_+ 6.6 54.7 -- 38 53 31.5 -- 27 33

(40 - 57) (49 - 63) (30, 33) Knee extension 57.3 _+ 25.0 85.4 -- 52 -- 55.5 -- 40

(31 - 108) (52 - 133) (46, 65) Elbow flexion 54.1 _+ 8.4 57.3 -- 35 -- 28.5 -- 22

(44 - 68) (42 - 68) (22, 35) Trunk flexion 44.5 _+ 15.0 45.1 53 20.0 37 --

(27 - 68) (42 - 47) (t5, 25) Trunk extension 37.7 _+ 5.6 45.1 74 22.0 50 --

(27 - 44) (42 - 50) (20, 24)

is rea l ized wi th a t o t a l of 28.6 m m in the college female. Es t ima te s of the percen tage b o d y fa t v a r y wi th t he convers ion scale t h a t is used; the fo rmula of D u r n i n and lCamahan [7] y ie lds h igh resul ts re la t ive to Yuhasz (who quotes t 0 . 6 % in t he " a v e r a g e " male and i 6 . 0 % in the "des i r ab l e" female).

Muscle Force. As m i g h t be an t i c ipa t ed f rom the b o d y weight and L.B.M. da ta , the o lder men were more muscu la r t h a n the younge r group, wi th p a r t i c u l a r l y m a r k e d d e v e l o p m e n t of knee ex tens ion force (Table 4). Pub l i shed d a t a on muscle s t r eng th is somewha t ske tchy , and resul t s are v e r y d e p e n d e n t upon the measur ing equ ipmen t used. However , our figures suggest t h a t t i le t r u n k s t reng ths of t he canoeis ts a re no t r emark- able. Grip s t r eng ths are high no rma l values , and knee and e lbow s t reng ths are well developed. I n keeping wi th th is assessment , the coefficients of cor re la t ion wi th ab i l i t y are for knee ex tens ion force 0.58 + 0.29, for summed h a n d g r i p force 0.29 + 0.34, for e lbow flexion force 0 . i t _+ 0.35, for s u m m e d back forces 0.13 + 0.35, and for the sum of al l six force read ings 0.45 _+ 0.32. I f force is expressed pe r ki lo of b o d y weight , corre la t ions d rop a lmos t to zero.

Lung Volumes. Lung vo lumes for the g roup as a whole were no t r e m a r k a b l e (Table 5). Values for the girls and o lder men were close to p r ed i c t ed levels, and in some of the younger men, resul t s were less t h a n would be p r ed i c t ed f rom age and height , w i th one F.V.C. on ly 83 % of n o r m a l according to the s t a n d a r d s of Mil ler et al. [ t t ] . Never theless , the re was a significant cor re la t ion be tween F.V.C. and abi l i ty , amoun t ing


Table 5. Lung volumes. Mean + S.D., range, compared with predicted values of Miller et al. [ i l l and Anderson et al. [i]

Forced vital capacity i see forced F.E.V.i.o (l. BTPS) expiratory F.V.C %

Observed Predicted (i. BTPS) Miller A~derson

Young males 4.77 _+ 0.5t 5.06 5.22 (n = 7) (3.89- 5.53) (4.70- 5.t0) (4.85- 5.59) Older males 5.t6 5.14 5.34 (n = 3) (4.85- 5.61) (4.83- 5.60) (5.02- 5.82) Females 3.70 3.82 3.76 (n = 2) (3.65, 3.74) (3.54,4A0) (3.44,4.08)

4.04 +_ 0.30 84.9 _+ 5.7 (3.55 - 4.33) (76.5 - 91.3) 4.54 88.0 (4.28 - 4.92) (87.7 - 88.2) 3.04 82.4

(2.98, 3A0) (79.8, 84.9)

to 0.64 +_ 0.27 for the absolute F.V.C., and 0.69 i 0.25 for the F.V.C. expressed as a percentage of the age and height predicted value, according to the standards of Miller et al. [ i i ] .

F.E.V.1. 0 readings were all within the normal range for healthy adults. Cardlorespiratory Variables. The predicted oxygen costs of running

[t5] for the sub-maximal tests were, respectively, 40, 45 and 49 ml/kg/min at a speed of 6 m.p.h, and slopes of 2, 4, and 6%; actual results were a little higher than this in the seven young athletes (40.3 _+ 1.3; 48.3 _+ 2.4; 52.9 • 2.5 ml/kg/min), but in the three older athletes (Po, He and Ke) figures were substantially below predictions (35.8 • 3.9; 41.6 • 2.5, 46.3 + 3.6 ml/kg/min). This may reflect in part the extensive treadmill training experience of two of the three older athletes.

Nine of the twelve athletes reached a clearly defined plateau of oxygen consumption (increment < 2 ml/kg/min with further increment of treadmill slope). Increments of oxygen consumption for the remaining three individuals were, respectively, 2.4, 2.5, and 5.6 ml/kg/min. Never- theless, the final pulse rates (194, 202, and 198/rain), gas exchange ratios (iA2, 1.07, IA0) and blood lactates (155, i i4 , i35 rag/100 ml) were such that we feel justified in accepting their final exercise data point as the directly measured maximal oxygen consumption.

The average maximum heart rates were well up to the anticipated level for the sedentary population [6] with the possible exception of the younger of the two girls [age i7 years, /~ (max)= 188/mini. The directly measured aerobic power was higher than we and Cumming [5] have found in some Canadian athletes, particularly when expressed per unit of body weight, but was inferior to the figures reported for the Swedish smooth water team [i3]. Predictions of aerobic power by the Astrand nomogram were reasonably accurate on a group basis, but single measurements on individual athletes had a substantial error; for the


Table 6. Cardio-respiratory variables for rest and maximum effort. Mean • S.D., range of results for progressive treadmill exercise

Young men Older men Women n = 7 n = 3 n = 2

]~est Oxygen consumption 249 + 13 281 232 (ml STPD/min) (229 - 268) (267 - 303) (217, 246) Hears rate (/min) 71 + 13 60 67

(58 - 90) (56 - 65) (66, 67)

Exercise Max. oxygen consumption (1. STPD/min) (ml STPD/kg/min)

Max. heart rate (/rain)

Max. respiratory minute Volume (t. BTPS/min) Resp. exchange ratio

Blood lactate (rag/t00 ml)

3.83 +_ 0.32 4.45 2.80 3 A 4 - 4.t3 (4.32 - 4.69) (2.70, 2.90)

60.0 + 3.3 55A 49.2 (5OA - 65.5) (50.t - 59.6) (45.9, 52.4)

t98 + 4 184 t93 (185 - 203) (182 - 186) (188, t98)

t39.2 • 15.6 t44.0 t13.4 (112- 157) ( t 3 0 - t62) (1tl - 1t5) t.12 + 0.07 1.11 1.06

(1.07 - 1.28) (1.07 - t.14) (1.02, t.10) 146 + 22 t27 121

(1t4 - t72) (96 - 147) (t08, t35)

Recovery Oxygen dept 6.60 _+ 0.97 7.24 4.61 (1. STPD) (5.02 - 7.66) (6.70 - 7.88) (4.54~ 4.67)

final 1/2 min of each of t he t h r e e s u b - m a x i m u m tests , d iscrepancies re la t ive to the d i r ec t l y measu red m a x i m u m oxygen i n t ake were as follows :

Error of .~strand prediction (ml/kg/min)

Load 1

Load 2

Load 3

Young males Older males Females (n = 7) (n = 3) (n = 2)

-1 .5 + 3.6 -1 .6 -6 .6 ( - 5 . 4 to +3.7) ( - 5 . 4 t o +12A) (-15.8, +2.6)

+0.6 + 3.2 -0 .4 -1.8 ( -4 .8 to +4.2) ( -8 .5 to +7.t) ( - 9 . t , +5.6)

+1.3 _+ 3.5 -2 . t +0.4 ( -5 .6 to +5.5) ( - 9 . 9 So +3.4) ( -5 .6 , +6.4)

The abso lu te aerobic power ( i . ]min) was pos i t i ve ly cor re la ted wi th overa l l ab i l i t y (r = 0.67 + 0.26). However , as migh t be an t i c ipa t ed f rom the a d v a n t a g e of t he h e a v y contes tan t , t he re was a s t a t i s t i ca l l y insigni . f icant negative re la t ionsh ip be tween r e l a t ive aerobic power and abi l i ty .

L a c t a t e levels a t the end of m a x i m u m exercise were gene ra l ly high, and pe rhaps because of diff icult ies in pa r t i t i on ing the oxygen deb t ,

64

1-60 t

o 1,50[

~ 1.40

,~ 1.30 I - r -

1.20

~ 1.111

> -

~ 1.00 t - -

--. O.90 % ~ 0.110

0.70

K. Sidney and Roy 3. Shephard

4/ . . . . . . . . . .

. . . . . . .

. . . . . . . . . ' ' '0 ' ' '3 '4 ' 1 2 3 4 5 6 "/ 8 9 ! 11 12 1 1 " 15 TIME OF RECOVERY (MINUTES)

Fig. 1. The respiratory gas exchange ratio during the first t5 rain recovery from sub-maximum effort: �9 �9 three male competitors with greatest overall ability; �9 . . . . . . �9 three male competitors with intermediate ability; [ ] - - - - - - [ ] four male competitors with least ability; ~ - - - zx two female competitors. In maximum effort, curves had a simular form, with a peak R of ~.48 - - 1.58 one to

two rain after cessation of effort

showed a somewhat bet ter correlation with tota l oxygen debt (ml/kg, r = 0.73) t han with the es t imated lactate component os the oxygen debt (ml/kg, r = 0.58). The equat ion for predict ion of blood lactate (Y) was:

Y = 16.0 + 1.25 (X) where (X) is the to ta l oxygen debt (ml/kg).

The t ime course of lactate release f rom the muscles was indicated approximate ly by the respira tory gas exchange ratio. As in most normal adults, this reached a peak l to 2 rain after cessation of b o t h m a x i m u m and sub-maximum effort (Fig. l). The form of the recovery curve did no t v a r y marked ly with ability, a l though there was some suggestion t h a t the three best paddlers had a somewhat later peak and slower recovery than the remaining seven men; this m a y be due to their greater age ra ther t han their compet i t ive ability.

The to ta l oxgyen debt was at the level ant ic ipated for fit subjects. Using the same techniques, Godin and Shephard (in preparat ion) found values os 7.3i I . (98.1 ml/kg) in Un ive r s i ty class swimmers, and 6.26 i . (85.5 ml/kg) in sedentary young men. A two te rm exponential funct ion of the type

y = aze-~,j.t + a~e-~,~


was fitted to the oxygen consumption measurements for the recovery period. This showed "half-times" of the order generally attributed to the alactate and lactate components of the oxygen debt:

Rapid component (min)

Slow component (rain)

Young males Older males Females (n=7) (n=3) (n=2)

0.43 _+. 0.07 0.53 0.41 (0.34 - 0.54) (0.45 - 0.62) (0.41, 0.41) t3.3 +_ 2.3 13.7 75.3

(10.6- 17.7) (10.5 - 18.5) (13.4, 17.t)

Previous da ta (Godin and Shephard, in preparat ion) showed hal f t imes of 0.50 and i3.0 min in Univers i ty class swimmers, and 0.49 and i6.6 rain in sedentary young men. Al though the absolute magni tude of the oxygen debt is larger in physical ly fit subjects, the rate of r epayment apparerl t ly remains relat ively unchanged. The tradi t ional physiological method of analysing the oxygen dept uses the technique of "curve- stripping". I n order to reduce the subject ivi ty of this approach, we arbitrari ly divided the overall curve into two components, basing the " lac ta te" slope on measurements made between the second and 15th min of the recovery period. Our results were then as follows:

Young males ( ~ 7 ) Volume Time (rain) (1. STPD)

Rapid component 1.93 0.41 +_ 0.05 (1.45- 2.57) (0.33 - 0.46)

Slow component 4.66 4.71 _+ 0.49 (3.17- 6.02) (3.85- 5.29)

Total (t. STPD) 6.60 + 0.97 -- (5.02- 7.66)

Older males (n=3)

Volume (1. STPD) 2.62

(2.25- 2.82) 4.63

(4.37- 5.06) 7.24

(6.70- 7.88)

Older males (n = 3) Time (rain)

Rapid component 0.50 (0.42- 0.58)

Slow component 4.47 (3.70- 5.43)

Total (t. STPD)

Girls (n = 2) Volume Time (min) (1. STPD) 1.45 0.40

(IA8, 1.71) (0.39, 0.41)

3.16 4.80 (3.36, 2.96) (4.21, 5.38) 4.61

(4.54, 4.67)

There was a significant correlat ion between tota l oxygen debt (l.) aud overall abili ty ( r = 0.68 + 0.26), bu t the relationship disappeared if oxygen debt was related to b o d y weight (ml/kg).

Recovery pulse curves showed at least two distinct components (Fig. 2). The form of the curves did no t differ among male subjects when these were classified on the basis of competi t ive success. However,

5 Europ. J. appl. Physiol., Vol. 32

66 K. Sidney and Roy J, Shephard

~ 16o !~-~.

100

~ 3 4 5 6 7 8 9 10 1 12 13 14 ~15

Tl/~IE OF RECOVERY (&~INUTES)

Fig. 2. The heart rate during the first 15 rain of recovery from maximum effort: Q - - O three competitors with greatest overall ability; �9 . . . . . . �9 three competitors with intermediate ability; c~- - -rn four male competitors with least

ability; A . . . . A two female competitors

the pulse rate of the girls remained at a substantially higher level throughout the later stages of observationl this is probably attributable in part to a higher resting pulse rate and in part to the thickness of sub- cutaneous fat, and thus the relative difficulty of heat dissipation.

Ventilation (Fig. 3) had a less marked two component curve; however, even after i5 rain of recovery, values were still 8 to 10 l/rain in excess of the resting level, apparently remaining elevated for somewhat longer in the more successful competitors.

Physiology and Per]ormance. The physiological variables contribut- ing to the description of overall ability are largely size related {Table 7). A simple rank order table may be based on the coach's assessment of overall ability. There is substantial agreement ( r= 0.87) between this assessment and the cumulat ive score derived from the objective data. The principal exception (Ke, rated third by the coach) is of some interest, since the results of the t971 national competition (Table L) confirmed the physiological rather than the coaching impression of this subject. The Olympic results suggest that his main weakness was in the area of

The Whi te -Water Paddler 67

140

z_ ~E

120

.N ~ 1 0 0

4O

20

, | l | , , ! , i ! , i ,

1 2 3 4 5 6 7 8 9 I 0 11 12 13

TIME OF RECOVERY (MINUTES)

| i

14 15

Fig. 3. The respiratory minute volume during the first 15 min of recovery from maximum effort: �9 �9 three competitors with greatest overall abil i ty; �9 . . . . . . �9 three competitors with intermediate abi l i ty; [ : ] - - - D four male

competitors wi th least abil i ty; A . . . . A two female competitors

Table 7. Male contestants arranged according to the coach's ra t ing of overall abi l i ty in white-water contests. Other data on summed muscle force, s tanding height, vi ta l capacity, aerobic power (1./rain), oxygen debt (I.), lean body mass and

years of experience shown in rank order

Con- Force Height Vital Aerobic Oxygen Lean Experi- Cumu- t es tan t capacity power debt body ence lat ive

mass score

P�9 4 8 6 10 10 8 10 56 Mu 9 9 9 6 8 7 8 56 Ke 10 10 l0 9 5 10 9 63 Tw 7 8 8 7 7 6 8 51 He 8 8 7 9 6 9 I 48 It�9 2 5 3 4 9 4 5 32 J�9 5 5 4 4 2 3 8 31 l~cK I 1 I 1 ~ 1 5 11 McC 3 2 5 2 3 5 2 22 Ha 6 3 3 6 4 2 5 29

5*


either skill or tolerance of international competition. Table 7 serves to emphasize the strengths and weaknesses of individual contestants. The top competitor (Po) could profit from further muscle development, 1Via from a development of aerobic power, and Ke from the development of anaerobic mechanisms. The coach rated "power" in the order Po > Ke > Mu, but "endurance" (presumably a combination of muscular and eardio-respira~ory endurance) in the order Ke > Po > lgn.

Discussion

1. Technical Aspects o/Testing. The use of treadmill tests in assessing athletes who participate in an upper body sport deserves comment. Our philosophy in measuring maximum oxygen intake was to assess cardio- respiratory power as one i tem of a substantial test bat tery. Irrespective of the type of sport in which an athlete may be involved, we believe this information is best obtained by an exercise such as treadmill running tha t involves most of the body muscle mass [i7]. In the present instance, the test mode was particularly appropriate, since the subjects had been habituated to the treadmill during their training programme.

I t has been suggested [6] tha t the maximum heart rate of the athlete is lower than tha t of the sedentary individual; we, also, have encountered some athletes who reach a plateau at a relatively slow rate, but the average for the present group was well up to sedentary standards. Possibly, the low heart rate is associated with a peripherally limited test (bicycle ergometer) as opposed to one tha t is centrally limited (such as treadmill running).

The Astrand nomogram [3] gives ~ reasonably accurate picture of aerobic power in the athletes as a group. I t is thus useful from an epi- demiologieal standpoint, but unfortunately it has rather limited applica- tion to the rating of individual contestants, where discrepancies of t5 % and more may arise.

2. Physiological Characteristics o] White-Water Paddlers. The picture of the well-endowed white-water contestant tha t emerges from this study is generally compatible with direct observation of the sport. The good competitor is tall, as this gives him extra leverage in steering. He is required to work extremely hard for up to 5 rain, and thus needs a well~developed aerobic power; however, as the body weight is not lifted greatly during paddling, the absolute maximum oxygen intake (l/rain) is of more importance than the relative figure (ml/kg/min). The overall endurance-type task is supplemented by frantic bursts of anaerobic activity when approaching a gate - - hence the value of a large oxygen debt. The muscles of the t runk and upper extremity are engaged in rhythmic work, and thus depend more on cardio-respirutory power then on great Strength. The legs, on the other hand, play an important


isometric role in holding the contestant within his craft, providing an essential counter-force to permit effective arm movement, and this probably explains the value of quadrieeps extension force to the successful contestant.

The apparent value of vital capacity might be dismissed as merely an expression of the success of tall paddlers. However, there remains an equally significant effect when lung volumes are related to normal height and age standards. This may reflect development of the chest muscles by paddling.

A substantial lean body mass is of value not only because it reflects muscle power, but also because the low centre of gravity contributes to the maintenance of balance. As would be anticipated from the sitting posture, the percentage of body fat has little bearing upon success - - indeed, because the bet ter paddlers are also somewhat older, they tend to be the fat ter members of the group.

3. Contribution to Coaching Science. Some previous a t tempts to predict athletic success from objective scores have been most discouraging. However, the present analysis suggests tha t in a contest such as the white-water slalom (where physical demands are high), objective procedures can describe at least 75 % of the variance in ability reported by a perceptive coach. Further, par t of the residual variance undoubtedly reflects errors of judgement or even frank bias on the par t of the coach; physiological testing may thus provide a useful objective counterweight to coaching opinion (as in the ease of lie, discussed above). The objective measurements also highlight weaknesses of the individual, and may thus have value in the development of personalized training programmes.

Naturally, there remains scope to improve the objective methods of assessment. While "years of experience" provides a very simple criterion, other measures of skill are needed. The relative merits of sports specific and more general tests must be resolved, and field methods devised tha t will carry the laboratory procedures from a few specialized eentres to a broad spectrum of athletes. Lastly, the statistical methods of combining information can probably be improved. To this point, we have assumed tha t the tests listed in Table 7 carry equal weighting. This simplifies data analysis, and is justified as a first assumption in view of the rather equal individual eoefficients of correlation between ability and test scores. However, a formal discriminant analysis would eliminate overlap between the various tests and allow a more precise weighting of individual results.

Aclcnowledgements. We much appreciate the cooperation of Mr. Eric Jones, Mr. Eric 3{unshaw, and the competitors from the white-water clubs in the Toronto Metropolitan region.


Re~erences I. Anderson, T. W., Brown, J. R., Hall, J. W., Shephard, 1~. J.: The limitations of

linear regressions for the prediction of vital capacity and forced expiratory volume. Respiration 25, 140--158 (1968)

2. Asmussen, E., I-Ieeboll-Nielsen, K., Molbech, S. : Muscle strength in children. In: International Research in Sport and Physical Education, Jokl, E., Simon, E., Eds. Springfield, Illinois: C. C. Thomas 1964

3. Astrand, I. : Aerobic work capacity in men and women with special reference to age. Acta physiol, scand. 49, Supp. 169 (1960)

4. Clarke, H. H.: Muscle strength and endurance in man. Englewood Cliffs, N.J. : Prentice I-]all 1966

5. Cumming, G. 1~. : Fitness testing athletes. Canad. Faro. Physician (August), 48--52 (1970)

6. Davies, C. T. ~ . : Commentary. Canad. reed. Ass. J. 96, 743 (t967) 7. Durnin, J. V. G. A., Ramahan, M. M. : The assessment of the amount of fat in

the human body from measurements of skinfold thickness. Brit. J. Nutr. 21, 681--689 (1967)

8. Howell, M. L., Loiselle, D. S., Lucas, W. G. : Strength of Edmonton School- children. Unpublished report, Fitness l~esearch Unit, University of Alberta, Edmonton, AlbeIta

9. Howell, N., Howell, M. L. : Sports and games in Canadian Life. 1700 to the present. Toronto : MacMillan 1969

10. Ishiko, T. : Aerobic capacity and external criteria of performance. Canad. reed. Ass. J. 96, 746--749 (t967)

t l . Miller, W. F., Johnson, R. L., Wu, ~N. : Relationships between fast vital capacity and various timed expiratory capacities. J. appl. Physiol. 14, 157--t63 (1959)

12. Mohme-Lundholm, E., Svedmyr, ~., Vamos, Iq. : Enzymatic micromethod for determining the lactic acid content of fingertip blood. Scand. J. clin. Lab. Invest. 17, 501--502 (1965)

13. Saltin, B., Astrand, P. 0. : Maximal oxygen uptake in athletes. J. appl. Physiol. 23, 353--358 (1967)

14. Seliger, V. : Circulatory responses to sports activities. In: Physical activity in health and disease, Evang, K., Andersen, K. L., Eds. Springfield, Illinois: C. C. Thomas 1966

15. Shephard, 1~. J. : A nomogram to calculate the oxygen cost of running at slow speeds. J. Sport ~ed. (Torino) 9, 10--16 (1969)

16. Shephard, R. J. : Computer programmes for solution of the Astrand nomogram. J. Sport Med. (Torino) 10, 206--2i0 (1970)

17. Shephard, 1~. J., Allen, C., Benade. A. J. S., Davies, C. T. M., di Prampero, P. E., Hedman, R., Merriman, J. E., Myhre, K., Simmons, R. : The maximum oxygen intake -- an international reference standard of cardio-respiratory fitness. Bull. Wld Hlth Org. 38, 757--764 (1968)

18. Ibid. Standardization of sub-maximal exercise tests. Bull. Wld Hlth Org. 38, 765--776 (1968)

19. Society of Actuaries: Build and Blood pressure study. Chicago, Illinois: 1959 20. Weiner, J. S., Lourie, J. A. : Human biology: A guide to field methods. Oxford:

Blaekwell 1969 21. Wohlfeil, T. : Uber den Energieverbrauch bei sportlieher KSrperarbeit (Kann-

fahren). Arch. Hyg. (Berl.) 100, 393--4tt (1928) 22. Yuhasz, M. : Physical Fitness and Sports Appraisal Laboratory Manual. London,

Ont. : Dept. of Physical Education, University of Western Ontario 1970

Profi R. J. Shephard, Dept. of Environmental Health, University of Toronto, School of Hygiene, ~150 College Street, Toronto 18i, Ontario, Canada

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Physiological characteristics and performance of the white-water paddler