No effect of short-term amino acid supplementation on variables related to skeletal muscle damage in 100 km ultra-runners - a randomized controlled trial

Background: The purpose of this study was to investigate the effect of short-term supplementation of amino acids before and during a 100 km ultra-marathon on variables of skeletal muscle damage and muscle soreness. We hypothesized that the supplementation of amino acids before and during an ultra-marathon would lead to a reduction in the variables of skeletal muscle damage, a decrease in muscle soreness and an improved performance. Methods: Twenty-eight experienced male ultra-runners were divided into two groups, one with amino acid supplementation and the other as a control group. The amino acid group was supplemented a total of 52.5 g of an amino acid concentrate before and during the 100 km ultra-marathon. Pre- and post-race, creatine kinase, urea and myoglobin were determined. At the same time, the athletes were asked for subjective feelings of muscle soreness. Results: Race time was not different between the groups when controlled for personal best time in a 100 km ultra-marathon. The increases in creatine kinase, urea and myoglobin were not different in both groups. Subjective feelings of skeletal muscle soreness were not different between the groups. Conclusions: We concluded that short-term supplementation of amino acids before and during a 100 km ultra-marathon had no effect on variables of skeletal muscle damage and muscle soreness

Untersuchungen zum Doppelpeak-Phänomen von Talinolol

keine AngabenOral absorption of the fti-adrenoreceptor blocker talinolol (TAL) is known to be incompletely and erratically. To evaluate the variables in TAL absorption, 100 mg of the drug were given together with paracetamol (100 mg) and retinyl palmitate (100.000 IU) in fast-disintegrating hard capsules, enteric coated capsules and rectal soft capsules to 8 male healthy volunteers (age 21-29 years, body weight 68-86 kg) who fasted for 10 hours before and 5 hours after administration. Food effects on TAL disposition were assessed by eating a continental breakfast at the moment of the expected first TAL peak one hour prior to administration of a hard capsule. Validated HPLC-assays were used for quantitative determinations. Results: Bioavailability of talinolol in enteric-coated and rectal capsules was significantly reduced by about 50 % and 80 %, respectively despite unchanged bioavailability of paracetamol. After TAL in hard capsules, typical double peak phenomena with peaks after 2-3 and 4-6 hours, respectively, occurred in all subjects. Food increased the maximum concentrations significantly (223±76 µg/ml versus 315±122 µg/ml, p<0.05) and shifted the second peak of TAL to shorter tmax (3.8±1.2 h vs 2.1 ±0.6 h, p<0.05) which was in accordance with faster absorption of vitamin A. Pharmacokinetic simulations showed that about half of oral TAL is not directly drained from intestine, which leads to a late second absorption peak in fasting subjects and which reaches blood earlier after a heavy meal. In conclusion, since TAL disposition is under control of P-glycoprotein and MRP2, ABC-transporters of gut mucosa (enterocytes, capillaries) might be involved in splitting TAL absorption into a direct and a delayed part that might be associated with lymphatic flow

Ad libitum fluid intake leads to no leg swelling in male Ironman triathletes - an observational field study

BACKGROUND: An association between fluid intake and limb swelling has been described for 100-km ultra-marathoners. We investigated a potential development of peripheral oedemata in Ironman triathletes competing over 3.8 km swimming, 180 km cycling and 42.2 km running. METHODS: In 15 male Ironman triathletes, fluid intake, changes in body mass, fat mass, skeletal muscle mass, limb volumes and skinfold thickness were measured. Changes in renal function, parameters of skeletal muscle damage, hematologic parameters and osmolality in both serum and urine were determined. Skinfold thicknesses at hands and feet were measured using LIPOMETER(R) and changes of limb volumes were measured using plethysmography. RESULTS: The athletes consumed a total of 8.6 +/- 4.4 L of fluids, equal to 0.79 +/- 0.43 L/h. Body mass, skeletal muscle mass and the volume of the lower leg decreased (p 0.05). The decrease in skeletal muscle mass was associated with the decrease in body mass (p >0.05). The decrease in the lower leg volume was unrelated to fluid intake (p >0.05). Haemoglobin, haematocrit and serum sodium remained unchanged (p >0.05). Osmolality in serum and urine increased (p <0.05). The change in body mass was related to post-race serum sodium concentration ([Na+]) (r = -0.52, p <0.05) and post-race serum osmolality (r = -0.60, p <0.05). CONCLUSIONS: In these Ironman triathletes, ad libitum fluid intake maintained plasma [Na+] and plasma osmolality and led to no peripheral oedemata. The volume of the lower leg decreased and the decrease was unrelated to fluid intake. Future studies may investigate ultra-triathletes competing in a Triple Iron triathlon over 11.4 km swimming, 540 km cycling and 126.6 km running to find an association between fluid intake and the development of peripheral oedemata