A common misperception about topline is that it can be improved through exercise alone. Lack of exercise – or the wrong type of exercise is often blamed for a poor topline. While exercise alters existing muscles, building new muscles is a different story. The nutritional building blocks of muscle (essential amino acids) must be present in sufficient quantities and balanced with adequate calories to rebuild or augment muscle tissue. In fact, if a horse is worked hard but his diet lacks sufficient amino acids, existing muscle mass can shrink. This can be a slippery slope in some situations, and as muscle atrophy sets in, the belief is that the horse needs to work even harder when in fact the fuel is not present (in the form of nutrition) to help support and repair tissue that is broken down with exercise. Just like human athletes, athletic equine partners need more essential amino acids than maintenance horses to maximize the effects of training and allow the horse to look and feel its best.
Certain exercises are thought to improve topline include hill work, backing exercises, and those that encourage the horse to collect and arc the body. These exercises can help condition muscles, but only if the diet is supporting the muscles through proper nutrition.