Epigenetics
Nova. "Epigenetics." July 24, 2007.
Cloud, John. "Why Your DNA Isn't Your Destiny." Time, January 6, 2010.
Hersh, Aaron. "Natural Born Athlete." Triathlete, March 2011.
Fitzgerald, Matt. "Will Genetic Doping Be the End of Sports?" Triathlete, April 2009.
Koubova, Jana, and Leonard Guarente. 
"How Does Calorie Restriction Work?" Genes & Development 17 (2003): 313–21.
Colman, Ricki J., et. al. "Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys." Science 325, no. 5937 (2009): 201–4.
Huffman, Derek M., et. al. "Effect of Exercise and Calorie Restriction on Biomarkers of Aging in Mice." American Journal of Physiology 294, (2008): R1618–27.
Dubé, J. J., et al. "Exercise-induced Alterations in Intramyocellular Lipids and Insulin Resistance: The Athlete's Paradox Revisited." American Journal of Physiology Endocrinology and Metabolism 294 (2008): E882–8.
Triathlon Tapering
Mujika, Inigo, Sabino Padilla, et al. "Physiological Changes Associated with Pre-event Taper in Athletes." Sports Medicine 34, no. 13 (2004): 891–927.
Hooper, Sue L., Laurel Traeger Mackinnon, et al. "Effects of Three Tapering Techniques on the Performance Forces and Psychometric Measure of Competitive Swimmers." European Journal of Applied Physiology and Occupational Physiology 78, no. 3 (1998): 258–63.
Hue, O., S. Antoine-Jonville, et al. "The Effect of 8 Days of Training in Tropical Environment on Performance in Neutral Climate in Swimmers." International Journal of Sports Medicine 28, no. 1 (2007): 48–52.
Morton, R. Hugh, John R. Fitz-Clarke, et al. "Modeling Human Performance in Running." Journal of Applied Physiology 69, no. 3 (1990): 1171–7. (This is an interesting article that develops a mathematical model of a runner.)
Triathlon Preparation
Jeukendrup, A., R. Jentjens, et al. "Nutritional Considerations in Triathlon." Sports Medicine 35, no. 2 (2005): 163–81.
Van Schuylenbergh, R., B. Vanden Eynde, et al. "Prediction of Sprint Triathlon Performance from Laboratory Tests." European Journal of Applied Physiology 91, no. 1 (2004): 94–9.
Peeling, P. D., D. J. Bishop, et al. "Effect of Swimming Intensity on Subsequent Cycling and Overall Triathlon Performance." British Journal of Sports Medicine 39, no. 12 (2005): 960–4.
Millet, G. P., and V. E. Vleck. "Physiological and Biomedical Adaptations to the New Cycle to Run Transition in Olympic Triathlon: Review and Practical Recommendations for Training." British Journal of Sports Medicine 34, no. 5 (2000): 384–90.
Energy Metabolism
Fitzgerald, Matt. "Lactic Acid Myths Debunked." Triathlete, Februrary 2009, 94–6.
Bacon, L., and M. Kern. "Evaluating a Test Protocol for Predicting Maximum Lactate Steady State." The Journal of Sports Medicine and Physical Fitness 39, no. 4 (1999): 300–8.
Vobejda, C., K. Fromme, et al. "Maximal Constant Heart Rate—A Heart Rate Based Method to Estimate Maximal Lactate Steady State in Running." International Journal of Sports Medicine 27, no. 5 (2006): 368–72.
Gladden, M. B. "Lactate Metabolism: A New Paradigm for the Third Millennium." Journal of Physiology 558, no. 1 (2004): 5–30. [Just read the first 8 pages.]
Pendergast, D., et al. "Energy Balance of Human Locomotion in Water." European Journal of Applied Physiology 90, no. 3–4 (2003): 377–86.
Alexander, R. M. "Models and the Scaling of Energy Costs for Locomotion." Journal of Experimental Biology 208 (2005): 1645–52.
Brooks, G. A. "Lactate Shuttles in Nature." Biochemical Society Transactions 30, no. 2 (2002): 258–64.
Bergman, B. C., et al. "Active Muscle and Whole Body Lactate Kinetics after Endurance Training in Men." Journal of Applied Physiology 87, no. 5 (1999): 1684–96.
Dubouchaud, H., et al. "Endurance Training, Expression, and Physiology of LDH, MCT1, and MCT4 in Human Skeletal Muscle." American Journal of Physiology Endocrinology and Metabolism 278, no. 4 (2000): E571–9.
Marathon Physiology
Almond, C. S. D., et al. "Hyponatremia among Runners in the Boston Marathon." New England Journal of Medicine 352 (2005): 1550–6.