The characteristics between skiers of the 4 different events seem to vary. According to the anthropometric skinfold thickness data evaluation of the last 10 years the successful skier is now taller and heavier than in the past.  Skiers have less bodyfat, nowadays, which indicates that the higher weight of the elite athletes is devoted to lean body mass. Slalom skiers are usually leaner than skiers of the other events, whereas downhill competitors are the heaviest.

Body composition appears to be an important factor in performance. Smaller, leaner males performed better in the Slalom (SL) events, while skiers with more bodyfat did better in downhill events.

Muscles have a mixture of two basic types of fibers, fast twitch and slow twitch. Fast-twitch fibers are capable of developing greater forces and contacting faster and have greater anaerobic capacity. In contrast, slow-twitch fibers develop force slowly, can maintain contractions longer and have higher aerobic capacity. The genes largely determine whether you have more of one kind of muscle fiber or another. It is not clear whether training can change the distribution of fiber types within an individual.  We may be geneticaly programmed with this respect.

Although some studies show that the percentage of slow twitch (ST) fibrers distribution is higher, others show that alpine skiers do not have a distinct fiber type composition but a tendency to a preponderance of slow twitch fibers. Nonetheless, both muscle fiber types are recruited during SL and GS runs.

The studies reported a FT/ST ratio in elite Alpine skiers is 1.14. In comparison the ratio for endurance athletes is 1.03 and for sprinters 1.52 on average.

The exercising muscle uses glycogen as both aerobic and anaerobic energy sources. Skilled skiers have the ability to reduce muscle glycogen more than recreational skiers.

Skilled skiers have greater glycogen depletion in the ST fibers compared with the unskilled. A possible explanation is that the experienced skier recruited more ST fibers because these fibers are more resistant to fatigue. GS has a greater glycogen utilization compared to SL.

Skiing is usually classified as an anaerobic event, considering the longest event, downhill, takes 3 minutes. However, it is difficult to differentiate between the contribution of the energy sources in the overall energy expenditure. Specially for this particular outdoor sport, laboratory conditions are difficult to reproduce, because the involved movements are not repetitive. Most studies investigating skiing, measured oxygen consumption in laboratory or in field settings. The results indicate that aerobic power is an important factor for successful skiing. High aerobic capacity increases the ability to recover from repeated bouts of anaerobic exercise, and allows the athlete to sustain aerobic work for a longer duration. Because most competitions occur at altitudes between 2500- 3500m adequate aerobic power is needed.

Elite alpine skiers have a high aerobic capacity compared to normal individuals. However the general aerobic power shown across elite alpine skiers is not very impressive. There is also high variation from one athlete to another.  Some exceptional results measured in an elite athlete, may reflect the training program of the athletes and not the actual demands of the sport. Some teams may emphasise more the aerobic work and their average VO_{2 max} may well reach 65-70 ml/kg/min.

Anaerobic power is important factor in skiing. The anaerobic contribution to the energy metabolism amounts 65% and anaerobic tests (repeated jump test, absolute power from vertical jump, 30 second Wingate test) appear to be better predictors of alpine skiing ability compared to aerobic power tests .

Skiers have very high leg strength compared to other athletes. Studies found that the most predicting performance factor in the US Ski Team men and women's is the leg strength.

Thigh muscles are important for balance as well as the initiation and completion of the turns. The hamstring muscles protect the knee by reducing the anterior shear that the quadriceps creates at the tibia. Furthermore very high leg strength is required to overcome the enormous external forces developed during skiing. Good developed muscles allows the skier to function at lower percentage of maximal strength which may result in less occlusion of blood flow and greater resistance to fatigue.

Since introduction of the shaped skis alpine skiing has changed significantly. Athletes are skiing smaller-radious turns, using more lateral movements and relatively little up-and-down movement. These changes relate to the construction of the ski, the binding and the boots result in an higher demand upon the absolute strength of the alpine skier.

Research shows that in SL and GS the energy sources are about 40 % aerobic, 20% alactic, and 40% lactic metabolism, hence conclusions drawn are that maximal aerobic power or aerobic capacity are unlikely determinants for success in high level skiing.

Alpine skiing always has been characterised as an explosive movement, perhaps because the high speed achieved, while performing lateral direction changes. However, research indicate that knee and hip angular velocities are quite slow even in SL. The knee joint angle velocity lies between 20-50 deg/s during concentric and eccentric action of a turning GS, and they are not much higher in a slalom race and marginally lower in SG.

No data are available for downhil but it could be assumed that the knee angular velocity is also low for both muscle actions. EMG measurements have shown that GS is dominated by eccentric muscle action. Although SG, GS and SL require slow knee angle movement using the knee extensor muscle in eccentric mode the studies failed to show that elite skiers have more eccentric strength than other power athletes.

Elite skiers can be differentiated from non-elite skiers on the basis of power, strength and motor characteristics. However, as skiing is a typical technique dependent sports, no special physiological variable is dominant that can definitely predict performance within high level performance athletes. Physiological tests however were found valid in talent identification. Furthermore tests can be used to monitor compliance and effectiveness of training and rehabilitation program following injury. Tests also have shown to be sports specific in terms of intensity and movement pattern, hence useful for the athlete's assessment to his or her readiness to return to on-snow training and competition.

Alpine Skiing - Fitness Testing Study (1998)