Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Award

Summer 2013

Document Type


Degree Name

Master of Science (MS)


Department of Kinesiology


Introduction: This study investigated the effects of carbohydrate and protein (CHO+Pro) supplementation during intensified training on cardiovascular adaptations and cycling performance. Methods: Five cyclists (VO2peak = 62.6 ± 10.7 ml/kg/min) performed two 27-day training protocols while receiving either CHO or CHO+Pro supplements. The exercise protocols consisted of 7 days of normal training (NT), 10 days of intensified cycle training (ICT; 100% increase in average training duration versus NT), and 10 days of reduced volume training (RVT; reduction in training duration to 60% of NT). Performance was assessed by a 30-km time trial following 120 min of constant-load cycling and VO2peak testing. Other physiological measures were assessed at rest (heart rate, hematocrit, hemoglobin, and albumin) and during exercise (heart rate, ventilation, RER, RPE, VO2, glucose, and lactate). Supplements were consumed during exercise (750 ml•hr-1; CHO = 6% concentration; CHO+PRO = 6% CHO, 2% Pro concentrations) and immediately following exercise (9.93 ml of fluid•kg BW- 1; CHO = 1.2 g CHO•kg BW-1; CHO+PRO = 1.2 g CHO•kg BW-1 + 0.3 g Pro•kg BW-1). Data was analyzed using magnitude-based inferences. Results: Time to complete the 30-km TT and average TT power were ‘likely’ impaired following ICT, with no differences between treatments. Following RVT, time to complete the 30-km TT and average TT power were ‘likely’ improved versus ICT, with no differences between treatments. Between NT and ICT constant-load HR significantly decreased (independent of treatment), with a ‘very likely’ larger reduction with CHO+Pro (135±13 bpm to 128±10 bpm) versus CHO (133±15 bpm to 132±13 bpm). Between NT and RVT, constant-load HR also ‘very likely’ declined to a greater extent with CHO+Pro (135±13 bpm to 132±14) than with CHO (133±15 to 138±16 bpm). Serum albumin was ‘likely’ increased following ICT and RVT (independent of treatment), but differences between treatments were ‘unclear’. Conclusion: These findings suggest exercising heart rates in well trained-cyclists are attenuated with carbohydrate and protein supplementation, although the cause of the reduced in HR is unclear. In addition, the implications of these findings require further study, as overall exercise tolerance and adaptations following intensified training were similar to those observed with carbohydrate supplementation.

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