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This study assessed the effect of combined jump training and collagen supplementation on bone mineral density (BMD) in elite road-race cyclists. In this open-label, randomized study with two parallel groups, 36 young (21 ± 3 years) male (n = 8) and female (n = 28) elite road-race cyclists were allocated to either an intervention (INT: n = 18) or a no-treatment control (CON: n = 18) group. The 18-week intervention period, conducted during the off-season, comprised five 5-min bouts of jumping exercise per week, with each bout preceded by the ingestion of 15 g hydrolyzed collagen. Before and after the intervention, BMD of various skeletal sites and trabecular bone score of the lumbar spine were assessed by dual-energy X-ray absorptiometry, along with serum bone turnover markers procollagen Type I N propeptide and carboxy-terminal cross-linking telopeptide of Type I collagen. BMD of the femoral neck decreased in CON (from 0.789 ± 0.104 to 0.774 ± 0.095 g/cm2), while being preserved in INT (from 0.803 ± 0.058 to 0.809 ± 0.066 g/cm2; Time × Treatment, p <.01). No differences between treatments were observed for changes in BMD at the total hip, lumbar spine, and whole body (Time × Treatment, p >.05 for all). Trabecular bone score increased from 1.38 ± 0.08 to 1.40 ± 0.09 in CON and from 1.46 ± 0.08 to 1.47 ± 0.08 in INT, respectively (time effect: p <.01), with no differences between treatments (Time × Treatment: p =.33). Serum procollagen Type I N propeptide concentrations decreased to a similar extent in CON (83.6 ± 24.8 to 71.4 ± 23.1 ng/ml) and INT (82.8 ± 30.7 to 66.3 ± 30.6; time effect, p <.001; Time × Treatment, p =.22). Serum carboxy-terminal cross-linking telopeptide of Type I collagen concentrations did not change over time, with no differences between treatments (time effect, p =.08; Time × Treatment, p =.58). In conclusion, frequent short bouts of jumping exercise combined with collagen supplementation beneficially affects femoral neck BMD in elite road-race cyclists. [ABSTRACT FROM AUTHOR]

Introduction: Protein ingestion during recovery from exercise has been reported to augment myofibrillar protein synthesis rates, without increasing muscle connective protein synthesis rates. It has been suggested that collagen protein may be effective in stimulating muscle connective protein synthesis. The present study assessed the capacity of both whey and collagen protein ingestion to stimulate postexercise myofibrillar and muscle connective protein synthesis rates. Methods: In a randomized, double-blind, parallel design, 45 youngmale (n = 30) and female (n = 15) recreational athletes (age, 25 ± 4 yr; bodymass index, 24.1 ± 2.0 kg·m-2) were selected to receive primed continuous intravenous infusions with L-[ring-13C6]-phenylalanine and L-[3,5-²H2]-tyrosine. After a single session of resistance type exercise, subjects were randomly allocated to one of three groups ingesting either 30 g whey protein (WHEY, n = 15), 30 g collagen protein (COLL, n = 15) or a noncaloric placebo (PLA, n = 15). Blood and muscle biopsy samples were collected over a subsequent 5-h recovery period to assess both myofibrillar and muscle connective protein synthesis rates. Results: Protein ingestion increased circulating plasma amino acid concentrations (P < 0.05). The postprandial rise in plasma leucine and essential amino acid concentrations was greater in WHEY compared with COLL, whereas plasma glycine and proline concentrations increased more in COLL compared with WHEY (P < 0.05). Myofibrillar protein synthesis rates averaged 0.041 ± 0.010, 0.036 ± 0.010, and 0.032 ± 0.007%·h-1 in WHEY, COLL and PLA, respectively, with onlyWHEY resulting in higher rates when compared with PLA (P < 0.05). Muscle connective protein synthesis rates averaged 0.072 ± 0.019, 0.068 ± 0.017, and 0.058 ± 0.018%·h-1 in WHEY, COLL, and PLA, respectively, with no significant differences between groups (P= 0.09). Conclusions: Ingestion of whey protein during recovery fromexercise increasesmyofibrillar protein synthesis rates. Neither collagen nor whey protein ingestion further increased muscle connective protein synthesis rates during the early stages of postexercise recovery in both male and female recreational athletes. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to assess the prevalence of low bone mineral density (BMD) in male and female elite cyclists at different stages of a professional cycling career and to identify potential risk factors of low BMD. Methods: In this cross-sectional study, 93 male and female early career, advanced career, and postcareer elite cyclists completed dual-energy x-ray absorptiometry at the hip, femoral neck, lumbar spine, and total body; blood sampling; assessment of training history and injuries; and the bone-specific physical activity questionnaire. Backward stepwise multiple regression analyses were conducted to explore associations between BMD and its potential predictors in early and advanced career (i.e., active career) cyclists. Results: With a mean Z -score of −0.3 ± 0.8, −1.5 ± 1.0, and −1.0 ± 0.9, low BMD (Z -score < −1) at the lumbar spine was present in 27%, 64%, and 50% of the early, advanced, and postcareer elite male cyclists, respectively. Lumbar spine Z -scores of −0.9 ± 1.0, −1.0 ± 1.0, and 0.2 ± 1.4 in early, advanced, and postcareer elite female cyclists, respectively, indicated low BMD in 45%, 45%, and 20% of these female subpopulations. Regression analyses identified body mass index, fracture incidence, bone-specific physical activity, and triiodothyronine as the main factors associated with BMD. Conclusions: Low BMD is highly prevalent in elite cyclists, especially in early career females and advanced career males and females. These low BMD values may not fully recover after the professional cycling career, given the substantial prevalence of low BMD in retired elite cyclists. Exploratory analyses indicated that low BMD is associated with low body mass index, fracture incidence, lack of bone-specific physical activity, and low energy availability in active career elite cyclists. [ABSTRACT FROM AUTHOR]

The current double blind, randomized, placebo-controlled trial with two parallel groups aimed to assess the impact of whey protein supplementation on recovery of muscle function and muscle soreness following eccentric exercise. During a 9-day period, forty recreationally active males received twice daily supplementation with either whey protein (PRO; 60 g/day) or an iso-energetic amount of carbohydrate (CON). Muscle function and soreness were assessed before, and 0, 3, 24, 48, and 72 h after performing 100 drop jumps. Recovery of isometric maximal voluntary contraction (MVC) did not significantly differ between groups (timextreatment, P = 0.56). In contrast, the recovery of isokinetic MVC at 90°·s−1 was faster in CON as opposed to PRO (timextreatment interaction, P = 0.044). Recovery of isokinetic MVC at 180°·s−1 was also faster in CON as opposed to PRO (timextreatment interaction, P = 0.011). Recovery of countermovement jump performance did not differ between groups (timextreatment interaction, P = 0.52). Muscle soreness, CK and CRP showed a transient increase over time (P < 0.001), with no differences between groups. In conclusion, whey protein supplementation does not accelerate recovery of muscle function or attenuate muscle soreness and inflammation during 3 days of recovery from a single bout of eccentric exercise. [ABSTRACT FROM AUTHOR]

This study assessed the effect of combined jump training and collagen supplementation on bone mineral density (BMD) in elite road-race cyclists. In this open-label, randomized study with two parallel groups, 36 young (21 ± 3 years) male (n = 8) and female (n = 28) elite road-race cyclists were allocated to either an intervention (INT: n = 18) or a no-treatment control (CON: n = 18) group. The 18-week intervention period, conducted during the off-season, comprised five 5-min bouts of jumping exercise per week, with each bout preceded by the ingestion of 15 g hydrolyzed collagen. Before and after the intervention, BMD of various skeletal sites and trabecular bone score of the lumbar spine were assessed by dual-energy X-ray absorptiometry, along with serum bone turnover markers procollagen Type I N propeptide and carboxy-terminal cross-linking telopeptide of Type I collagen. BMD of the femoral neck decreased in CON (from 0.789 ± 0.104 to 0.774 ± 0.095 g/cm2), while being preserved in INT (from 0.803 ± 0.058 to 0.809 ± 0.066 g/cm2; Time × Treatment, p < .01). No differences between treatments were observed for changes in BMD at the total hip, lumbar spine, and whole body (Time × Treatment, p > .05 for all). Trabecular bone score increased from 1.38 ± 0.08 to 1.40 ± 0.09 in CON and from 1.46 ± 0.08 to 1.47 ± 0.08 in INT, respectively (time effect: p < .01), with no differences between treatments (Time × Treatment: p = .33). Serum procollagen Type I N propeptide concentrations decreased to a similar extent in CON (83.6 ± 24.8 to 71.4 ± 23.1 ng/ml) and INT (82.8 ± 30.7 to 66.3 ± 30.6; time effect, p < .001; Time × Treatment, p = .22). Serum carboxy-terminal cross-linking telopeptide of Type I collagen concentrations did not change over time, with no differences between treatments (time effect, p = .08; Time × Treatment, p = .58). In conclusion, frequent short bouts of jumping exercise combined with collagen supplementation beneficially affects femoral neck BMD in elite road-race cyclists.