Nothing new in negative training

Eve Zibart’s “Negative Training” article speaks to an important workout principle: A muscle loaded when it is lengthening is a powerful way to achieve fitness [“Negative Training: A Positive Move for Your Muscles,” March 5].

However, the salutary effect of negative training is not new knowledge. I recall that President Kennedy’s White House physician, Janet Travell, M.D., championed this technique during the 1960s and 1970s.

One of her favorite negative exercises was the “sit-back” as an alternative to the “sit-up,” an exercise not mentioned in Ms. Zibart’s article.

WILLIAM K. SOLBERG, DDS

West Los Angeles