Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Skeletal Muscle Strength and Endurance
PB Collins1, CP Earnest1, RL Dalton1, RJ Sowinski1, TJ Grubic1, BK Sanchez1, CJ Favot1, AG Reyes1, AM Coletta1, C Rasmussen1, M Greenwood1, PS Murano2, RB Kreider1*
1 Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, Texas, USA
2 Institute for Obesity and Program Evaluation, Texas A&M University, College Station, Texas, USA
3 Nutrabolt, Bryan, Texas, USA
Corresponding author: [email protected]
Background
This study examined the short-term effects of ingesting a ready-to-drink pre-workout supplement (RTD) on muscular performance.
Methods
Resistance-trained participants (n=25) ingested in a randomized, double-blind, crossover manner a dextrose placebo (PLA, 12g) and RTD containing caffeine (200mg), β-alanine (2.1g), niacin (65mg), folic acid (325mcg), Vitamin B12 (45-mcg), and arginine nitrate (1.3g) for 7d interspersed by a 7d washout. Participants performed a 1RM and 3 x 10 repetitions at 70% 1RM on the bench press (BP) and leg press (LP); ingested the assigned supplement, then had BP and LP 1RM’s determined followed by repetitions to failure (RtF) at 70% 1RM on days 1 and 6. A 4-km cycling time trial (TT) was performed on Days 2 and 7. Data were analyzed by MANOVA adjusted for sex and relative caffeine dose and are presented as mean change, 95% CI’s.
Results
Acute RTD ingestion increased BP lifting volume (70.4, CI 20, 120; PLA 1.96, CI -48, 52 kg). After 6d, both groups increased BP lifting volume (RTD: 108, CI, 59, 157; PLA: 102, CI 54, 152 kg) while LP lifting volume (900, CI 169, 1,632; PLA -968, CI -2,558, 623 kg) and combined lifting volume (1,008, CI 262, 1,755; PLA 383, CI -362, 1,130 kg) were increased in RTD but not PLA. Post-supplementation BP 1RM decreased in both groups at Day 1 (RTD: -2.6, CI, -4.0, -1.2; PLA: -4.4, CI -5.8, -3.0 kg) and Day 6 (RTD: -2.8, CI -4.1, -1.6; PLA: -1.8, CI -3.1, -0.57 kg). No change was observed in LP 1RM for RTD while PLA significantly decreased at Day 1 (RTD: 1.7, CI, -11.1, 14.6; PLA: -15.3, CI -28.2, -2.4 kg) and Day 6 (RTD: -7.4, CI -25.5, 13.8; PLA: -23.8, CI -45, -2.6 kg). RtF increased after acute RTD ingestion (RTD: 2.0, CI, 0.8, 3.3; PLA: -0.4, CI -1.6, 0.9) while both groups improved following 6-d (RTD: 2.8, CI, 1.7, 4.0; PLA: 2.1, CI 1.0, 3.3) TT performance from Day 2 to 7 improved with PLA with no differences between treatments (RTD: -5.72, CI -15.47, 4.0; PLA: -11.48, CI -21.23, -1.73 sec; RTD: 8.1, CI -4.4, 20.7; PLA: 18.2, CI, 5.7, 30.8 W).
Conclusions
Acute RTD use enhanced lifting volume while short-term RTD supplementation improved muscular endurance (RtF and lifting volume) and maintained LP 1RM strength but had no effects on 4km cycling time trial performance in resistance-trained college-aged participants.
Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Hematological Response to Postural Challenge
PB Collins1, RJ Sowinski1, CP Earnest1, RL Dalton1, TJ Grubic1, BK Sanchez1, CJ Favot1, AG Reyes1, AM Coletta1, C Rasmussen1, M Greenwood1, PS Murano2, RB Kreider1*
1 Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, Texas, USA
2 Institute for Obesity and Program Evaluation, Texas A&M University, College Station, Texas, USA
3 Nutrabolt, Bryan, Texas, USA
Corresponding author: [email protected]
Background
Nitrates have been claimed to cause perturbations in blood pressure response, specifically increasing the risk of orthostatic hypotension. The purpose of this study was to investigate the effects of short-term ingestion of a ready-to-drink pre-workout supplement (PWS) on hemodynamic response to changes in posture.
Methods
Resistance-trained participants (n=25) ingested in a randomized, double-blind, crossover manner a: (1) Dextrose placebo (PLA, 12g) and, (2) PWS containing caffeine (200mg), β-alanine (2.1g), niacin (65mg), folic acid (325mcg), Vitamin B12 (45mcg), and arginine nitrate (1.3g) in a randomized, crossover manner for 7d, interspersed by 7d washout. We employed a tilt table protocol as a postural challenge to assess hemodynamics. Hemodynamics were analyzed by MANOVA adjusted for sex and relative caffeine dose presented as mean change from baseline (95% CI).
Results
Prior to acute supplementation, HR increased from supine to standing for both groups (PWS: 8.25, 95% CI, 4.7, 12; PLA: 8.9, 95% CI, 5.4, 12.5 bpm) and the same occurred at Day 6 (PWS: 7.1, 95% CI, 3.1, 11.1; PLA: 10.8, 95% CI, 6.9, 14.8 bpm). Only PLA increased HR post-ingestion at Day 1 (6.4, 95% CI, 2.9, 9.9 bpm) and Day 6 (9.3, 95% CI, 5.7, 13 bpm) while no changes were seen following PWS ingestion (Day 1: 2.4, 95% CI, -1.2, 6 bpm; Day 6: 3.2, 95% CI, -0.5, 6.9 bpm). SBP increased from supine to standing following PLA ingestion on Day 6 (2.1, 95% CI, 0.05, 4.1 mmHg) with no differences seen with PWS (0.5, 95% CI, -1.6, 2.6 mmHg). No other significant changes were seen with SBP. DBP also increased in the PLA treatment from supine to standing at Day 6 pre-ingestion (2.9, 95% CI, 1.1, 4.7 mmHg) with no change seen following 6d of PWS ingestion (0.8, 95% CI, -1, 2.7 mmHg). Mean arterial pressure was increased after ingestion of the PLA on Day 6 (14.3, 95% CI, 7.3, 21.2 mmHg) with no change following PWS ingestion (5.2, 95% CI, -1.8, 12.3 mmHg). No significant changes were seen in rate pressure product responses for either group at any time point.
Conclusions
Results indicate that use of this PWS prior to exercise for up to 7d does not affect heart rate or blood pressure responses to a hemodynamic challenge in resistance-trained males and females.
Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Blood Chemistry and Self-Reported Side Effects
PB Collins1, CJ Favot1, CP Earnest1, RL Dalton1, RJ Sowinski1, TJ Grubic1, BK Sanchez1, AG Reyes1, AM Coletta1, C Rasmussen1, M Greenwood1, PS Murano2, RB Kreider1*
1 Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, Texas, USA
2 Institute for Obesity and Program Evaluation, Texas A&M University, College Station, Texas, USA
3 Nutrabolt, Bryan, Texas, USA
Corresponding author: [email protected]
Background
This study examined the effects of short-term ingestion of a ready-to-drink pre-workout supplement (RTD) on blood chemistry responses and self-reported side effects.
Methods
Resistance-trained participants (n=25) ingested in a randomized, double-blind, crossover manner a: (1) Dextrose placebo (PLA, 12g) and, (2) RTD containing caffeine (200mg), β-alanine (2.1g), niacin (65mg), folic acid (325mcg), Vitamin B12 (45mcg), and arginine nitrate (1.3g) in a randomized, crossover manner for 7-d, interspersed by 7d washout. Fasting 8h blood samples were assessed for plasma nitrate, whole blood counts, liver, kidney, and muscle function, and a metabolic panel. A side effects questionnaire was obtained twice on each testing day (Days 1, 2, 6, and 7). Data were analyzed by MANOVA adjusted for sex and relative caffeine dose and presented as mean change from baseline (95% CI). The frequency of side effects and blood chemistry changes from baseline were analyzed using Pearson’s Chi Square analysis.
Results
Plasma nitrate concentration increased from Day 1 to Day 7 in the RTD treatment (0.06, 95% CI, 0.003, 0.124 µM) with no change in PLA (0.02, 95% CI, -0.05, 0.08 µM). No significant overall statistical effects were observed for remaining blood chemistry markers. Chi Square analysis of blood chemistry changes from Day 1 to Day 7 did not reveal any significant change from baseline with the exception of nitrates. No overall effects were observed in severity of side effect (p=0.42). As expected with β-alanine ingestion, participants consuming the RTD tended to report skin tingling or paresthesia (p=0.07).
Conclusions
Results indicate that use of this RTD prior to exercise for up to seven days does not have a negative impact on liver, kidney, or muscle blood chemistries or cause any unexpected side effects in college-aged, resistance-trained males and females.
Acknowledgements
This study was supported by Nutrabolt (Bryan, TX) through an unrestricted research grant provided to Texas A&M University. CP Earnest serves as a Director of Clinical Sciences for Nutrabolt. RB Kreider serves as a university approved scientific advisor for Nutrabolt. PS Murano serves as quality assurance supervisor.