delivra topical creatine for improving muscular power

Conditions: Muscle Weakness

Summary: creatine is a nutritional supplement that is often ingested to improve exercise performance. the advent of a new product that is applied to the skin overlying muscle offers potential benefit, if the creatine can be targeted to specific muscles. the investigators are testing a novel creatine cream to determine the effects on human muscular performance. the investigators are assessing the acute application of two different doses of the creatine cream on muscular power (determined by knee extension).

creatine monohydrate is a popular nutritional supplement with athletes involved in sports involving strength and power. when creatine is orally ingested it combines with inorganic phosphate to form phorylcreatine (pcr) in skeletal muscle . adenosine triphosphate (atp) is the immediate source of energy in muscle - during exercise atp is broken down to adenosine diphosphate (adp) and inorganic phosphate. duration of high-intensity exercise is limited to a few seconds based on limited atp stores in muscle. pcr acts to re-phosphorylate adp to form atp so that muscle contraction can continue at high intensities. after creatine monohydrate is ingested, high-intensity exercise capacity is increased because of the increased pcr stores in muscle. delivra inc. has developed a topical cream containing creatine that is designed to penetrate the skin. the study purpose is to determine whether the topical cream, at two different doses, is effective for improving muscular strength and power. the hypotheses are that the experimental topical creatine cream will be more effective than a placebo cream for improving muscular performance and that two consecutive applications of creatine cream is more effective than a single application for improving muscular performance. the study involves a involves a double-blind placebo-controlled parallel group design. participants (n=132) will be randomized to receive either a low dose (3.5 ml) or high dose (7 ml) of topical creatine. the baseline assessment involves measuring muscular power during 5 sets of 15 repetitions of knee extension on a dynamometer, with each set separated by 1 minute rest, with each leg tested separately. at least 72 hours after the baseline testing, participants will receive either a high or low dose of the topical creatine cream applied to the quadriceps of one leg. the high-dose group will receive 3.5 ml of creatine cream 30 minutes and 15 minutes to one leg (randomized) before exercise testing (i.e. the same testing as performed in visit 2). they will receive 3.5 ml of placebo cream 30 and 15 minutes to the opposite leg before testing. the low-dose group will receive placebo cream 30 minutes before testing and creatine cream 15 minutes before testing to one leg; they will receive placebo cream 30 and 15 minutes before testing on the opposite leg. testing on each leg will involve measuring muscular power during 5 sets of 15 repetitions of knee extension on the dynamometer, with each set separated by 1 minute rest. the primary outcomes are average and peak power output.

Eligibility criteria:
inclusion criteria: * physically active and able to pass physical activity readiness questionnaire exclusion criteria: * allergies to any ingredients in the cream * answering "yes" to physical activity readiness questionnaire * currently pregnant or breastfeeding, * presence of significant medical disorder that would compromise the participant's safety to take part in the trial (eg: cancer, immunosuppressed) * history of alcohol or drug abuse within the past year * anyone using recreational drugs * use of performance enhancing drugs or supplements within 2 months including caffeine and creatine in supplement form * currently using other topical agents for treatment of pain or inflammation