3athlon - #dnf is no option

Dienstag, 2. Juli 2013

Science: Direct and indirect lactate oxidation in trained and untrained men

Lactate has been shown to be an important oxidative fuel. We aimed to quantify total lactate oxidation rate (Rox) and its direct versus indirect (glucose that is gluconeogenically derived from lactate and subsequently oxidized) components (mg·kg(-1)·min(-1)) during rest and exercise in humans. We also investigated the effects of endurance training, exercise intensity, and blood lactate concentration ([lactate]b) on direct and indirect lactate oxidation. Six untrained (UT) and six trained (T) men completed 60 min of constant load exercise at power outputs (PO) corresponding to their lactate threshold (LT). Trained subjects completed two additional 60-min sessions of constant load exercise at 10% below the LT workload (LT-10%), one of which included a lactate clamp (LT-10%+LC). Rox was higher at LT in T (22.7 ± 2.9, 75% VO2peak) compared to UT (13.4 ± 2.5, 68% VO2peak, P < 0.05). Increasing [lactate]b (LT-10%+LC, 67% VO2peak) significantly increased lactate Rox (27.9 ± 3.0) compared to its corresponding LT-10% control (15.9 ± 2.2, P < 0.05). Direct and indirect lactate oxidation rates increased significantly from rest to exercise and their relative partitioning remained relatively constant in all trials, but differed between T and UT: direct oxidation comprised 75% of total lactate oxidation in UT and 90% in T suggesting the presence of training-induced adaptations. Partitioning of total carbohydrate (CHO) utilization showed that subjects derived one-third of CHO energy from blood lactate, and exogenous lactate infusion significantly increased lactate oxidation, causing a glycogen sparing effect in exercising muscle.

http://www.ncbi.nlm.nih.gov/m/pubmed/23788576/

Montag, 1. Juli 2013

Science: Update on stress fractures in female athletes: epidemiology, treatment, and prevention

Stress fractures are a common type of overuse injury in athletes. Females have unique risk factors such as the female athlete triad that contribute to stress fracture injuries. We review the current literature on risk factors for stress fractures, including the role of sports participation and nutrition factors. Discussion of the management of stress fractures is focused on radiographic criteria and anatomic location and how these contribute to return to play guidelines. We outline the current recommendations for evaluating and treatment of female athlete triad. Technologies that may aid in recovery from a stress fracture including use of anti-gravity treadmills are discussed. Prevention strategies may include early screening of female athlete triad, promoting early participation in activities that improve bone health, nutritional strategies, gait modification, and orthotics.

http://link.springer.com/article/10.1007%2Fs12178-013-9167-x

IRONMAN Copenhagen to take place on 18. August 2013

Recently acquired Danish races like former Challenge Copenhagen will take place as planned. IRONMAN Copenhagen will start at 18. August. A press conference will outline more details on 2. July. WTC's CEO Andrew Messick and YWC's Chairman of the board Jeppe Rindom, both will attend. Meanwile TEAMChallenge's CEO Felix Walchshöfer has terminated contracts with local Danish race organizers and pre-announced a new race. Details on 5. July.