Creatine Timing on Resistance Training Adaptations in College Athletes
Condition: Healthy
Study type: Interventional

Summary: 
      While the use of creatine monohydrate supplementation and its associated benefits are well
      researched and supported, the impact of the timing of when creatine is ingested is a highly
      nuanced topic. The potential for the timing of administration to make an impact on observed
      outcomes is an established and appreciated factor and limited research to date has examined
      the impact of creatine timing. Of the literature that has been published, one study was very
      short in duration (4 weeks) that possessed a study design that undermined its practicality,
      two other studies used older individuals, and one study utilized a unilateral training model
      which may not be an adequate exercise protocol to allow for the ergogenic potential of
      creatine to mediate any enhancement of training adaptations. Therefore, based on the limited
      number of studies in young and previously trained populations, future studies examining the
      effects of pre vs post-training creatine monohydrate supplementation on resistance training
      adaptations are warranted.
    

Detailed description: 
      In a randomized, double-blind, placebo-controlled, parallel design, eligible study
      participants were provided a daily dose of creatine monohydrate (pre-or post-workout) or
      placebo (no creatine delivered) for an 8-week supplementation period. Based upon their
      baseline fat-free mass, participants were randomized into one of three groups: pre-workout
      creatine supplementation (PRE), post-workout creatine supplementation (POST), or placebo
      (PLA). Each group consumed their assigned dose or placebo within one hour before exercise and
      within one hour following exercise. Each assigned supplement was consumed with 12-16 ounces
      of fluid along with a 25-gram dose of whey protein isolate and a 25-gram dose of carbohydrate
      powder This additional supplementation was provided to aid in blinding and to help ensure
      adequate dietary protein intake was provided to promote increases in lean body mass and
      strength. Providing daily doses of carbohydrates and protein also helped with recruitment
      efforts as all study participants received some efficacious nutrients.

      All participants completed a twelve-week resistance training and conditioning program. The
      first four weeks of resistance training (12 workouts) occurred before supplementation began
      and were completed to acclimate participants to the program and to initiate early
      neuromuscular adaptations commonly seen with starting a new resistance training program. In
      addition, this initial 4-week period allowed for some study participants to wash out from
      ongoing supplementation prior to beginning the supplementation protocol. After completion of
      this run-in period, participants then completed baseline testing as described and began the
      supplementation protocol while continuing to follow the resistance training program for an
      additional eight weeks. Before and after the 8-week supplementation and resistance training
      period, body mass, body water, and body composition were assessed in addition to changes in
      muscular strength, muscular endurance, and lower-body power. All statistical analysis was
      completed on data collected starting at the beginning and end of the supplementation period.
      Participants were provided nutritional recommendations in order to ensure adequate energy and
      protein consumption to facilitate positive training adaptations and reduce the potential
      influence of differing dietary intakes.
    

Intervention name(s): Creatine; Maltodextrin
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Participants were matched according to fat-free mass to consume a placebo, or 5-g dose of creatine monohydrate within one hour before training, or within one hour after training for 8 weeks while completing a weekly resistance training program. At each time point (before and after training), all participants co-ingested a 25-gram dose whey isolate and a 25-gram dose of carbohydrate powder along with their assigned supplement. Body composition using a 3-compartment field (3CFIELD), muscular strength (one-repetition maximum [1RM]) and endurance (repetitions to fatigue [RTF] at 80% 1RM) using bench press (BP) and back squat (SQ) exercises along with isometric mid-thigh pull (IMTP) were assessed before and after the 8-week supplementation period.; Participants were matched according to fat-free mass to consume a placebo (maltodextrin) within one hour before training, or within one hour after training for 8 weeks while completing a weekly resistance training program. At each time point (before and after training), all participants co-ingested a 25-gram dose whey isolate and a 25-gram dose of carbohydrate powder along with their assigned supplement. Body composition using a 3-compartment field (3CFIELD), muscular strength (one-repetition maximum [1RM]) and endurance (repetitions to fatigue [RTF] at 80% 1RM) using bench press (BP) and back squat (SQ) exercises along with isometric mid-thigh pull (IMTP) were assessed before and after the 8-week supplementation period.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: randomized, double-blind, placebo-controlled, parallel design
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: supplementation; pre-workout; post-workout; peri-workout; strength; endurance; body composition; fat-free mass