The acute effects of thermogenic fitness drink formulas containing 140 mg and 100 mg of caffeine on energy expenditure and fat metabolism at rest and during exercise

Nicolas W Clark; Adam J Wells; Nicholas A Coker; Erica R Goldstein; Chad H Herring; Tristan M Starling-Smith; Alyssa N Varanoske; Valeria L G Panissa; Jeffrey R Stout; David H Fukuda

doi:10.1186/s12970-020-0341-4

The acute effects of thermogenic fitness drink formulas containing 140 mg and 100 mg of caffeine on energy expenditure and fat metabolism at rest and during exercise

J Int Soc Sports Nutr. 2020 Feb 13;17(1):10. doi: 10.1186/s12970-020-0341-4.

Affiliations

¹ School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA.
² Department of Sport, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
³ School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA. david.fukuda@ucf.edu.

Abstract

Background: Thermogenic fitness drink formulas (TFD) have been shown to increase energy expenditure and markers of lipid metabolism. The purpose of the current study was to compare TFD formulas containing different caffeine concentrations versus a placebo drink on energy expenditure and lipid metabolism at rest and during exercise.

Methods: Thirty-two recreationally active participants (22.9 ± 0.7 y, 167.1 ± 1.4 cm, 68.8 ± 2.0 kg, 24.0 ± 1.2% fat) who were regular caffeine consumers, participated in this randomized, double-blind, crossover design study. Participants reported to the laboratory on three occasions, each of which required consumption of either a TFD containing 140 mg or 100 mg of caffeine or a placebo. Baseline measurements of resting energy expenditure (REE) and resting fat oxidation (RFO) were assessed using indirect calorimetry as well as measurements of serum glycerol concentration. Measurements were repeated at 30, 60, 90 min post-ingestion. Following resting measures, participants completed a graded exercise test to determine maximal oxygen uptake (V̇O_2max), maximal fat oxidation (MFO) and the exercise intensity that elicits MFO (Fat_max), and total energy expenditure (EE).

Results: A significant interaction was shown for REE (p < 0.01) and RFO (p < 0.01). Area under the curve analysis showed an increased REE for the 140 mg compared to the 100 mg formula (p = 0.02) and placebo (p < 0.01) and an increased REE for the 100 mg formula compared to placebo (p = 0.02). RFO significantly decreased for caffeinated formulas at 30 min post ingestion compared to placebo and baseline (p < 0.01) and significantly increased for the 140 mg formula at 60 min post-ingestion (p = 0.03). A main effect was shown for serum glycerol concentrations over time (p < 0.01). No significant differences were shown for V̇O_2max (p = 0.12), Fat_max (p = 0.22), and MFO (p = 0.05), and EE (p = 0.08) across drinks.

Conclusions: Our results suggest that TFD formulas containing 100 and 140 mg of caffeine are effective in increasing REE and that a 40 mg of caffeine difference between the tested formulas may impact REE and RFO in healthy individuals within 60 min of ingestion.

Keywords: Caffeine; Caloric expenditure; Energy drinks; Exercise; Fat oxidation.

Publication types

Comparative Study
Randomized Controlled Trial

MeSH terms

Adolescent
Adult
Beverages
Caffeine / pharmacology*
Calorimetry, Indirect
Cross-Over Studies
Double-Blind Method
Energy Metabolism*
Exercise Test
Exercise*
Female
Glycerol / blood
Humans
Lipid Metabolism*
Male
Performance-Enhancing Substances / pharmacology*
Rest
Young Adult

Substances

Performance-Enhancing Substances
Caffeine
Glycerol

Grants and funding

1063638/Celsius Holdings Inc.