REVIEW ARTICLE Sports 0112-1642/96/00040262/$07.50/0Med. 1996 Apr; 21 262-276 O Adjs International Limited. All rights reserved. Applied Physiology of Water-Skiing Scott H. Leggett, l Kevin Kenneyl and Terry Eberhardt2 1 UCSD Orthomed, La Jolla, California, USA 2 Eberhardt Physical Therapy, Shreveport, Louisiana, USA Contents Summary 262 1 . Musculature Requirements 263 1 . 1 Slalom 263 1 .2 The Jump 265 2. Descriptive Characteristics of Water-Skiers 266 2. 1 Body Composition 266 2.2 Aerobic and Anaerobic Power 267 2.3 Strength 268 3. Strength and Conditioning for Water-Skiing 269 3. 1 Training Principles 269 3.2 Periodisatjon 270 4. Training Session Components 2n 4. 1 Warm-Up 271 4.2 Cardiovascular Training (Aerobic and Anaerobic) 272 4.3 Resistance Training 273 4.4 Cool-Down 274 4.5 Other Resistance Training Considerations 274 5, Conclusions 275 Summary Water-skiing is a physically demanding sport involving highly coordinated movements, extreme upper body torques, sustained isometric contractions and near maximal stresses on the anaerobic system. Due to the physical demands of the sport, elite skiers have developed physiological characteristics similar to other elite athletes. However, until recently little research has focused on the kinesiology, physiology and physical conditioning of water-skiing. Competitive water-skiing requires significant ski (fig. 3) involves factors of which many people physiological attributes specific to the sport. The are unaware of. process of turning a slalom ski (fig. 1), taking off In short, a slalom ski course consists of 6 buoys from a 1.83mjump (fig. 2), or manoeuvering a trick and 2 end-gates. A successful pass consists of skiing Applied Physiology of Water-Skiing 263 through both gates and around each buoy in approximately 18 seconds without falling. A tow boat will stop briefly at the end of each pass and shorten the tow line, until the skier misses a buoy or falls in the course. The anaerobic power, muscular strength and skill required for this event are remarkable. Isometric torques in excess of 950 N • m and speeds over 80 krn/h have been observed in the slalom course at the professional level (American Water Ski Association, personal communication). The rope length at this level of competition literally does not Fig. 1. The process of turning a slalom ski. match the perpendicular distance between the tow boat and the buoy. Thus, skiers must use the length @ of their body to extend around the buoy. The trick event is similar to the slalom event except the rope length is held constant while the skier performs in a straight path. Two consecutive trials are allowed to perform as many tricks as posSible in 20 seconds. Boat speed may vary depending on the sex and skill of the skier. In similar fashion, the jump competition allows 3 consecutive passes (jumps) with brief rest periods between each pass. Jump lengths will vary and the world record is set at over 61m (220 feet). To date, there is a paucity of data in the scientific community on the sport of water-skiing. Therefore, Fig. 2. A skier taking off from a 1.83m jump. the purpose of this article is 3-fold: first, to describe the muscular demands of the sport; secondly, to review the physiological profiles of water-skiers; individualised, we have chosen not to critique the and thirdly, to review the rationale of current exact muscular requirements of this event. The recommended training regimens for waterskiers. muscles used in the 3 phases of slalom and jump turns are summarised in table I. 1. Musculature Requirements 1 .1 Slalom There are 3 events for traditional water-skiing: There are 3 phases in the slalom turn. slalom, jump and tricks. In the sections which follow, the anatomical components required for the 7.7.1 The Deceleration Phase slalom and jump events are analysed for muscular The deceleration phase is when the skier begins conditioning implications. Since the trick event to slow their ski down to initiate the turn. Normally requires so many variations of movements and is so it begins as soon as the skier has crossed the second wake behind the boat, however at slower boat speeds she/he may have to wait until 2 to 3m after the second wake. In other words, deceleration and the changing of the edge of the ski to help facilitate deceleration varies according to boat speeds and Adis International Limited. All rights reserved. Sports Med 1996 Apr; 21 (4) 264 Leggett et al. rope lengths. The faster the skier travels, the sooner The knees are pushed forward while keeping the they must start. upper body in the same position. This requires Anatomical position of the shoulders should be coordinated contraction of the hamstrings and erect, facing square to the shore with the knees and quadriceps, while the hip muscles (flexors and ankle bent as far forward as possible, and with the extensors) control the motion of shifting the ski to handle held close into the body with arms flexed. the inside edge. At the same time as the skier This action requires sustained isometric contraction changes edges and pushes with the knees, the of the quadriceps, gluteus maximus, latissimus outside hand comes off the handle and starts the dorsi, biceps and forearm flexors. Proper body second phase of the turn called the reach. position is maintained by strong continuous contraction of the rectus abdominis, trapezius, back 7. 7.2 The Reach Phase extensors, hip flexors, gluteus maximus and the calf The reach phase begins as the skier starts to (gastrocnemius and soleus). extend their inside arm towards the direction of the From this proper body position, the edge change pull of the boat. The skier does not put the handle is quite smooth and quick. The speed that is accu- All down towards the water nor above the shoulder, but reaches out to a natural position and allows room to get around the buoy. Strong contraction of the latissimus dorsi and pectoralis major is required for execution of this action, as well as a firm grip from the forearm flexors. The skier must stay in the correct position and force the head to stay up. Proper execution requires the rectus abdominis, neck extensors, gluteus maximus, quadriceps and calf to stabilise and maintain this correct position. During the reach, the ski rolls onto its inside edge even more, which in turn slows the skier down and sets her/him up for the turn, and the final phase of the turn — the acceleration phase. l. 1.3 The Acceleration Phase The acceleration phase is very important in finishing the slalom turn. One of the keys to achieving a great run is the pulling in of the handle quickly at the end of the turn. In order to bring in the handle (towards the skiers torso), the skier must have reached (maximally) Fig. 3. A skier manoeuvering a trick ski. toward the boat during the turn. At the finish of the turn, the handle needs to be pressed against the outside hip to ensure proper anatomical body mulated from the pull through the wakes keeps position for the pull. To get it there requires 2 momentum going away from the buoy as the motions, and they involve both arms and great waterskier begins the deceleration phase. This is strength. when the skier rolls the ski onto its inside edge. This Using the handle arm, the skier pulls the handle action puts weight on the front of the ski, thus straight in toward the outside hand utilising the unweighting the tail of the ski so it can begin to latissimus dorsi, biceps and forearm flexors. The decelerate for a smooth turn. O Adis International Limited. rights reserved. sports Med. 1996 Apr; 21 (4) Applied Physiology of Water-Skiing 265 skier must reach straight out, then pull straight in. The outside elbow is lifted up to shoulder height to keep the body up and balanced. The outside hand is kept about waist high to be ready to retrieve the handle quickly. At the same time, the outside arm reaches for the handle, meeting it about half way. The motion of the outside arm coming to meet the handle helps to turn the shoulders toward the wake, in the direction of the pull and increases acceleration. Positioning of the arms and pulling the handle to the hip primarily requires the latissimus dorsi, trapezius, deltoids, biceps and forearm flexors. The back extensors keep the back flexed, and the shoulders and chest are held up and erect by contraction of the trapezius and rhomboids. The arms are in at Adis International Limited. All rights reserved. Sports Med 1996 Apr; 21 (4) 266 Leggett et al. Table l. Muscles used in the 3 phases of slalom and jump manoeuvres the skis approximately 900 to the left while trying to maintain as much water speed as possible. This phase is very important because the Deceleration phase Rectus abdominus skiers must begin with good anatomical position in Biceps order to prevent the boat from pulling them out of Forearm flexors position when they begin the acceleration phase. Hip flexors The anatomical position begins with the shoulders Gluteus maximus erect, facing square across the boat wake, with the Quadriceps knees and ankles bent forward pushing 70 to 80% Gastrocnemius and soleus on the right ski and 20 to 30% on the left ski. The Latissimus dorsi handle is held down at the centre of gravity with the Back extensors right arm flexed at the elbow and the left arm Trapezius slightly extended and reaching across the body.