Life Fitness

The intake of pre-workout supplements is more popular than ever before. About 70% of young adults take at least one nutritional supplement before working out. These pre-workout supplements are claimed to ramp up the body energy and improve muscle strength and endurance. Caffeine, one of the ingredients commonly available for pre-workouts, is proven to improve muscular endurance and delay fatigue. In this blog, I will introduce a research study about caffeine to demonstrate the effects that it has on body performance.

The study, The Effect of Acute Pre-Workout Supplementation On Power and Strength Performance, was conducted by a group of people from the University of South Florida. Their research specifically tested the effects of caffeine-containing pre-workout supplements on anaerobic power and upper and lower body strength.

Procedures

Thirteen male volunteers with age=24±6 yrs, height=180.3±5 cm; body mass=83.4±9 kg participated in the study. Throughout the study, the group had four weekly lab visits. Prior to each trial, no food, caloric beverage or caffeine consumption within 3 h was allowed, as well as no strenuous physical activity within 24 h. Throughout the four-week program, all participants performed their regular training programs outside of the lab.

• First Visit: Researchers introduced instructions of completing a 24h food log, standardized dynamic warm-up, and the four performance tests-MBP, VJ, 1-RM, and WAnT.
• Second Visit: Participants submitted the completed 24-hour food log for replicating the same food intake prior to each future trial. Then, they finished baseline assessments of the four performance tests, and researchers recorded participants’ height, weight, and blood pressure for future references.
• Third Visit: Participants were randomly provided with caffeine-containing pre-workout supplements (14.5 g of powder containing 10 calories, 3 g of carbohydrate, and 0 g of fat) or a placebo (a pseudo drink that doesn’t effect training performance), and performed all of the four tests 20 min after taking the supplements/placebos.
• Fourth Visit: Participants were provided with the opposite pre-workout treatments, and performed all of the four tests after 20 min.

For all of the performance assessments, a 5-minute warm up was done to prepare for more intensive physical activity. Following a 3-minute break, the tests were performed in the order of MBP, VJ, 1-RM, and WAnT, also separated by a 3-minute rest period in between.

Upper Body Power-Medicine Ball (MB)

After completing a warm-up, participants sat in front of a 45° incline bench and pushed a 9 kg medicine ball from their chest to make the ball roll up the incline. A chalk and measuring tape were used to find the traveling distance. Three attempts were allowed with a 2 min break after each trial.

Lower Body Power-Vertical Jump (VJ)

A jump and reach test was used to measure knee extension power, which reflects the lower body power. To measure out the jumping height, an overhead swivel vane was utilized. Participants were expected to hold their arms straight overhead to displace the vanes. The highest displaced vane would be recorded as the maximum jumping height. Two attempts were allowed with a 2 min break in between.

Upper Body Strength-One Repetition Maximum (1-RM) Bench Press

First, the participants performed a warm-up with a standard barbell for 12 repetitions. Then, participants started with a load of 75% of the anticipated maximum and added weights in three-four higher intensity trials to find their 1-RM bench press. A 2 min break was taken between each trial.

Anaerobic Power-Wingate Anaerobic Cycle Test

Participants first performed a 2 min pedaling warm-up at 60 rpm followed by an all-out sprint for the last two seconds of the first minute. Upon the completion of the two minutes, another 30-second-all-out sprint against a resistant force (7.5% of body weight in kg) was done to test the peak power, mean power, minimum power, and fatigue index.

Results

The computer software program SPPSS was used to analyze the data. Researchers concluded that the pre-workout supplement (SUP) caused a significant increase in anaerobic peak power and anaerobic mean power compared to the results given by placebo (PL) and baseline assessments (BA) (See the figure below). No significant effects were found for MB, VJ, 1-RM or fatigue index.

The research proved that the intake of a caffeine-containing pre-workout supplement can improve anaerobic strength performance. Therefore, to maximize your strength results, you can consider drinking a caffeine-containing pre-workout supplement 20 min prior to your workout.