Analysis of energy expenditure of skiers across the preparatory phase

Energy expenditure was calculated at rest and during physical activity by indirect calorimetry using the Oxyson Pro system in 55 highly elite skiers. The results showed that in 75% of athletes, the measured rest energy expenditure were higher than the calculated rest energy expenditure by 20% and was 2139±363 kcal/day. Daily energy expenditure was 5347±907 kcal. In the structure of rest energy expenditure the part of carbohydrates was 67 % and fats was 33%. Generally, energy expenditure was more 5000 kcal. In addition, in our study, it was observed a progressive increase of contribution of carbohydrate oxidation in energy expenditure during high-intensity exercise. Key words: energy expenditure, high-intensity exercise, carbohydrates, fats, skiers, indirect calorimetry.

Different disc characteristics between young elite skiers with diverse training histories revealed with a novel quantitative magnetic resonance imaging method

Purpose To evaluate if there are differences in thoraco-lumbar disc characteristics between elite skiers and non-athletic controls as well as between different types of elite skiers, with diverse training histories, using a novel quantitative MRI method. Methods The thoraco-lumbar spine of 58 elite skiers (age = 18.2 ± 1.1 years, 30 males) and 26 normally active controls (age = 16.4 ± 0.6 years, 9 males) was examined using T2w-MRI. Disc characteristics were compared quantitatively between groups using histogram and regional image analyses to determine delta peak and T2-values in five sub-regions. Results A statistical difference in the delta peak value was found between skiers and controls (p <0.001), reflecting higher degree of disc degeneration. The histogram analysis also revealed that the type of training determines where and to what extent the changes occur. Alpine skiers displayed lumbar changes, while mogul skiers displayed changes also in the thoracic spine. Alpine skiers with diverse training dose differed in delta peak value (p = 0.005), where skiers with highest training dose displayed less changes. Regional T2-value differences were found in skiers with divergent training histories (p <0.05), reflecting differences in disc degeneration patterns, foremost within the dorsal annulus. Conclusion Differences in quantitative disc characteristics were found not only between elite skiers and non-athletic controls but also between subgroups of elite skiers with diverse training histories. The differences in the disc measures, reflecting tissue degradation, are likely related to type and intensity of the physical training. Future studies are encouraged to explore the relation between disc functionality, training history and pain to establish adequate prevention and rehabilitation programs.

Hip pain and its correlation with cam morphology in young skiers—a minimum of 5 years follow-up

Background There is conflicting evidence regarding the association between cam morphological changes and hip pain, and it remains unclear who with cam morphology will develop hip pain and who will not. This study aimed to investigate the correlation between cam morphology, hip pain, and activity level at a 5-year follow-up in young Alpine and Mogul skiers. Method All students (n = 76) at Åre Ski National Sports High School were invited and accepted participation in this prospective study at baseline. Magnetic resonance imaging (MRI) of both hips was conducted to evaluate the presence of cam morphology (α-angle ≥ 55°) and its size alongside the reporting of hip pain, type, and frequency of training by the Back and hip questionnaire, at baseline. After 5 years, the skiers were invited to complete a shortened version of the same questionnaire. Results A total of 60 skiers (80%) completed the follow-up questionnaire, of which 53 had concomitant MRI data. Cam morphology was present in 25 skiers (47.2%, 39 hips). Hip pain at baseline and at follow-up was reported in 17 (28.3%) and 22 (36.7%) skiers, respectively. No correlations were found between the activity level, the frequency, and the size of cam morphology and hip pain, except for the right hip α-angle at 1 o’clock and hip pain in skiers with cam morphology at baseline (rs = 0.49; P = 0.03) and at follow-up (rs = 0.47; P = 0.04). A total of 73.3% skiers had retired, of which 48% reported this was due to injuries. Conclusion Hip pain was not shown to be correlated, or had a low correlation, with activity level and the presence and size of cam morphology in young skiers on a 5-year follow-up. Based on these results, cam morphology or activity level did not affect hip pain to develop during 5 years of follow-up in young skiers. Furthermore, this study highlights that almost 75% of young elite skiers had retired from their elite career with almost 50% reporting that this was due to injuries sustained from skiing.