To determine the retention of flexibility 25 days after 5 days of three 30-second stretches.
A 2 × 4 repeated-measures factorial. Treatment and time were independent variables. The dependent variable was flexibility as measured by a sit-and-reach box.
33 college students were tested before and after stretching for 5 consecutive days and without stretching on days 8 and 30. Control subjects were prone for 15 minutes; stretch subjects received 15 min of diathermy or sham diathermy and then performed three 30-second standing right-hamstring stretches.
Flexibility was greater on days 5, 8, and 30 than day 1, but days 5, 8, and 30 were not different from each other.
Gains in flexibility are retained for at least 3 weeks after a stretching program. It also appears that 2 sets of 3 repetitions of a sit-and-reach test is sufficient stimulus to induce long-term flexibility gains.