1. Sigma Xi Brown-bag Lunch October 16, 2009 Dr. Wes Dudgeon

2. Background What is TRX ® /suspension training? What is TRX /suspension training? Body Weight resistance Unstable surfaces Requires “Core” muscle use for all exercises Emphasizes flexibility Interval-Type training

3. Where do we (I) come in? Many claims made by manufacturer, but……… No Data to Back it up!! Research questions we asked (this time): What is the “stress” placed on the body by a TRX ® workout? (HR, BP, RPE) What is the “metabolic effect” of a typical TRX ® workout? (caloric expenditure, substrate usage)

4. Study Design Descriptive study 9 college age males (21.4  0.9 years, 176.7  3.3 cm, 68.8  3.6 kg, 13.4  1.7% body fat) 2 Familiarization sessions Testing day included: BodPod for body fat %, Fitting of a HR monitor, attachment to Metabolic Cart ® (ParvoMedics), insertion of indwelling venous catheter 30 min resting energy expenditure 60 min training session 120 min cool down

5. Variables of Interest HR BP Respiratory Exchange Ratio (RER) Caloric Expenditure (kcals/min) Blood Lactate food + O 2  CO 2 + H 2 O + energy (ATP) RER = VCO 2 / VO 2 reflects ratio of CHO and fat metabolism 100% CHO metabolism, RER = 1.0 e.g. C 6 H 12 0 6 +6 O 2  6 CO 2 / 6 O 2 = 1.0 100% fat metabolism, RER = 0.7 e.g. C 16 H 32 +23 O 2  16 CO 2 / 23 O 2 = 0.7 1:1 CHO to fat ratio, RER = 0.83 assumes (incorrectly) no protein is used

6. Example Testing Session

12. # # = great than both RMR and EPOC

15. Conclusions Effective method of burning calories, while also providing additional caloric expenditure above baseline during a two-hour recovery Using 30 sec work intervals followed by 60 sec rest periods elicited lactate and heart rate responses indicative of moderate intensity exercise Carbohydrates were the primary fuel source during the TRX workout, while lipids were the predominant source during recovery