The aim of this pilot study was to determine the pressure distribution, symmetry of load between operated (OP) and non-operated (NOP) leg, and pain level during alpine skiing in participants with unilateral total knee arthroplasty (TKA). The responses of the dependent variables were analyzed following a 10-week guided skiing intervention of 2-3 days of skiing per week. Ground reaction force (GRF) was recorded bilaterally and was determined for 13 participants with TKA (65 +/- 4 years) at pre- and post-test. Additionally, pain perception was determined using a numeric rating scale in the OP leg at both test sessions and after each skiing day. No statistical differences were observed between OP and NOP legs for peak and average GRF as well as the asymmetry indices at pre-test. Pain perception was low and was not increased as a consequence of the skiing intervention. In conclusion, alpine skiing did not lead to increased or decreased loading of the OP leg compared with the NOP leg. Therefore, alpine skiing may be allowed for patients with skiing experience and a good clinical outcome.

We investigated the effect of alpine skiing for 12 weeks on skeletal muscle characteristics and biomarkers of glucose homeostasis and cardiovascular risk factors. Twenty-three patients with a total knee arthroplasty (TKA) were studied 2.9 +/- 0.9 years (mean +/- SD) after the operation. Fourteen patients participated in the intervention group (IG) and nine in the control group (CG). Blood samples and muscle biopsies were obtained before (PRE) and 7.3 +/- 0.8 days after (POST) the intervention, and blood samples again after a retention (RET) phase of 8 weeks. With skiing, glucose homeostasis improved in IG (decrease in fasting insulin, increase in muscle glycogen) but not in CG. Fiber type distribution and size, as well as capillary density and number of capillaries around the fibers (CAF), were not different between the operated and the non-operated leg in either group. The relative number of type I fibers increased with skiing in IG with no change in CG. Inflammatory biomarkers, plasma lipids, and mitochondrial proteins and activity did not change. Alpine skiing is metabolically beneficial and can be used as a training modality by elderly people with TKA.

Downhill skiing in the elderly increases maximal oxygen uptake (VO2max) and carbohydrate handling, and produces muscle hypertrophy. We hypothesized that adjustments of the cellular components of aerobic glucose combustion in knee extensor muscle, and cardiovascular adjustments, would increase in proportion to VO2max. Nineteen healthy elderly subjects (age 67.5 +/- 2.9 years) who completed 28.5 days of guided downhill skiing over 3 months were assessed for anthropometric variables, cardiovascular parameters (heart rate, hematocrit), VO2max, and compared with controls (n=20). Biopsies of vastus lateralis muscle were analyzed for capillary density and expression of respiratory chain markers (NDUFA9, SDHA, UQCRC1, ATP5A1) and the glucose transporter GLUT4. Statistical significance was assessed with a repeated analysis of variance and Fisher's post-hoc test at a P value of 5%. VO2max increased selectively with ski training (+7 +/- 2%). Capillary density (+11 +/- 5%) and capillary-to-fiber ratio (12 +/- 5%), but not the concentration of metabolic proteins, in vastus lateralis were increased after skiing. Cardiovascular parameters did not change. Fold changes in VO2max and capillary-to-fiber ratio were correlated and were under genetic control by polymorphisms of the regulator of vascular tone, angiotensin converting enzyme. The observations indicate that increased VO2max after recreational downhill ski training is associated with improved capillarity in a mainly recruited muscle group.

The aim of this study was to monitor the long‐term effects of skiing on the health‐related parameters of older individuals. This paper describes the overall study design and the intervention phase. The study utilized a randomized control group design consisting of an intervention group ( n =27; age: 67.5 ± 2.8 years) and a control group ( n =20; age: 67.3 ± 4.4 years). Parameters of interest were measured during pre‐, post‐ and retention‐test sessions. The intervention phase lasted for 12 weeks, with an average of 28.5 days of guided skiing. Daily heart rate (HR) profiles and global positioning system data throughout the ski day were recorded. Perceived exertion levels as well as mood status of the subjects were recorded regularly. The intervention group completed an average of 4885 vertical meters of downhill skiing, with a total skiing distance of 40.5 km/day. In the skiing phase, the average physiological load was 72.4 ± 8.9% of HR max . The dimension “positive mood” referred to skiing (on scale of 0–10), with an average value of 7.6 ± 1.7 after skiing. The dimension of “negative mood” was much less pronounced, having a mean of 1.1 ± 1.5 after skiing. Two subjects suffered injuries while falling during skiing. The effects of the 12‐week skiing intervention on the tested parameters will be reported in the following papers of this supplementum.

Alpine skiing is a recreational sport with high demands on the cardiovascular and neuromuscular systems. It is assumed that skiing could have positive effects on the decline in aerobic capacity, strength, and balance ability of older individuals. In a 12-week intervention study, 47 elderly subjects (age 60-76 years) were randomized into an intervention group (IG) and a control group (CG). The IG averaged 28.5 days of guided skiing during 12 weeks. Aerobic capacity, leg power, and strength as well as postural stability were tested before, immediately after, and 10 weeks after the intervention phase. VO(2 max) improved by 7.2% from Pre to Post for the IG, without any change in the CG. Jump height increased on average by 6% over the 12 weeks for the IG, while jump height for the CG deteriorated by -11.7%. Dynamic maximal strength measured in both legs increased by 16% in the IG during the 12 weeks of skiing. In the CG, it increased by 7%, without being significant. In postural ability, no differences between groups or over time were noted. It appears that, in older individuals, 12 weeks of skiing leads to a significant increase in aerobic capacity, leg muscle power, and strength.

The aims of this applied field study were (1) to provide descriptive data on the biomechanical variables of parallel ski steering, carving in long radii and individual technique skiing modes of older recreational skiers and (2) to determine the relationships between biomechanical and physiological variables during these skiing modes. The mean knee angle (MKA), range of knee angle (RKA), ground reaction forces (GRF), co‐loading of the inner leg, mean heart rate (HRave), blood lactate (LA) and mean arterial pressure were determined for 14 older skiers (61.1 ± 5.4 years). The mean GRF did not differ between the skiing modes. Parallel ski steering resulted in a greater MKA, lower RKA and lower peak GRF compared with carving in long radii and individual technique. LA correlated positively to RKA during carving in long radii and individual technique, while HRave correlated negatively to MKA during parallel ski steering and carving in long radii. No significant relationships were found between the physiological and kinetic variables. In conclusion, dynamic skiing styles may result in increased muscle fiber recruitments, hence greater LA levels. Along with potentially greater loading of knee extensor muscles, lower MKAs may reduce perfusion and hinder substrate metabolism, consequently making ski turning more strenuous. Skiing with less knee flexion and a reduced RKAs could be recommended for older recreational skiers.

Alpine ski races are typically won by fractions of a second. It is therefore essential for ski racers to minimize air drag as well as ski–snow friction. In contrast to air drag, ski–snow friction during actual skiing has rarely been investigated so far. Two tasks, forward/backward leaning and edging of the skis, were selected, which (a) were expected to have an impact on ski–snow friction, and (b) could be executed while gliding in tucked position. Two hypotheses were tested: (H1) Run times are affected by forward or backward leaning. (H2) Run times are affected by edging of the skis. Four professional ski testers were recruited, who conducted a total of 68 runs of straight gliding. Execution of the tasks was documented by video recordings and by measuring the force application point on the skis of one tester. The findings of this study support (H2) but not (H1). There are indications that the increased run times for edging are caused by increased ski–snow friction. From a performance point of view, it seems beneficial for ski racers to minimize edging in the gliding sections of a race.

Since many years teaching concepts in alpine skiing are based on practice experiences and scientific research. Different tools are available to improve specific deficits. One of these tools is the so called “Alpine Basic Position” (ABP), which describes a particular body position. If one is trained in this, he is able to react on balance fluctuations, immediately. Furthermore it is possible to control movements in a harmonic and precise way, which is very important for steering skies exact and controlled. The determination of the force application point (FAP) is an important parameter to analyze body movements. In this study a fully qualified ski instructor (A) and an intermediate skier (B) were asked to fulfil five different exercises, which were developed for training the ABP. While A was skiing in a constant way, B was responding differently. Some exercises occurred a similar characteristic – in accordance to A -, some not.