Greater Reliance on Carbohydrates during Single Leg Versus Double Leg Cycling
Main Article Content
Keywords
Exercise, Metabolism, Skeletal muscle.
Abstract
Introduction: Small muscle mass exercises, such as single leg cycling, allow for greater muscle specific workload which should result in greater reliance on carbohydrate oxidation (CarbOx). However, the metabolic consequences to smaller muscle mass exercise have not been fully elucidated.
Purpose: To determine differences in CarbOx and fat oxidation (FatOx) between single-leg (SL) and double-leg (DL) cycling when performed at similar VO2. Methods: Ten healthy college students completed two separate 30-minute bouts of SL and DL cycling at 45% of VO2peak. Oxygen consumption, respiratory exchange ratio (RER), CarbOx, FatOx, HR and power were recorded throughout the exercise. Paired samples t-tests were utilized to identify differences in all dependent variables between cycling conditions.
Results: Matching oxygen consumption required a slightly lower power output for the SL condition (86±25 W) compared to DL (94±30 W). Despite similar kcal expenditure between the two cycling modalities, participants had 7% greater RER (0.92±0.03 versus 0.86±0.05; p=0.001), 45% greater CarbOx (p<0.001) and 37% reduced FatOx (p<0.001) during SL compared to DL cycling.
Conclusion: Thus, inclusion of smaller muscle mass activities into exercise training may enhance skeletal muscle glucose uptake kinetics, which would benefit athletes, and help with blood glucose control for those with diabetes.
References
2. Abbiss CR, Karagounis LG, Laursen PB, et al. Single-leg cycle training is superior to double- leg cycling in improving the oxidative potential and metabolic profile of trained skeletal muscle. J Appl Physiol. 2011.
3. Bjorgen S, Hoff J, Husby VS, et al. Aerobic high intensity one and two legs interval cycling in chronic obstructive pulmonary disease: the sum of the parts is greater than the whole. Eur J Appl Physiol. 2009;106(4):501-507. doi:10.1007/s00421-009-1038-1
4. Dolmage TE, Goldstein RS. Response to one-legged cycling in patients with COPD. CHEST. 2006;129(2):325-332. doi:10.1378/ chest.129.2.325.
5. Duner H. Oxygen uptake and working capacity in man during work on the bicycle ergometer with one and both legs. 1959;46(1):55-61. doi:10.1111/j.1748-1716.1959.tb01736.x
6. Magnusson G, Sylven C, Karlberg KE, Isberg B, Saltin B. Peak skeletal muscle perfusion is maintained in patients with chronic heart failure when only a small muscle mass is exercised. J Eur Soc Cardiol. 1997;33(2):297-306.
7. Kristiansen S, Hargreaves M. Progressive increase in glucose transport and GLUT-4 in human sarcolemmal vesicles during moderate exercise. Am J Physiol. 1997;272(3).
8. Esposito, F., Reese, V., Shabetai, R., Wagner, P. D., & Richardson, R. S. (2011). Isolated quadriceps training increases maximal exercise capacity in chronic heart failure: the role of skeletal muscle convective and diffusive oxygen transport. J Am Coll Cardiol, 58(13), 1353-1362.