Even though age results in decreased flexibility, the effect of resistance training (RT) frequency on functional flexibility in middle-aged women has not been well studied.
PURPOSE: This study evaluated the effects of a 3 versus 4 day RT program on changes in flexibility of the arms of the dominant and non-dominant hand as well as the lower body.
METHODS: Twenty-one untrained women (age 48±1.2 years; BMI 28.9±1.1) completed 8 weeks of RT. Self-selected groups enhanced adherence to training in group 3 (G3) or group 4 (G4). G3 trained total body 3 days a week and G4 trained 4 consecutive days alternating upper and lower body exercises. G4 completed 3 sets of 6 upper body exercises (chest press, latissimus pulldown, shoulder press, machine row, triceps pushdown, biceps curl) or 6 sets of 3 lower body exercises (leg press, leg extension, leg curl). G3 completed 3 sets of the same exercises (excluding machine row) used for split training by G4. Both groups completed 72 sets of 8-12 repetitions at 50-80% 1RM per week. A control group of 7 untrained women (age 50±6.5 years; BMI 31.9±7.2) completed no exercise but only pre-post flexibility testing. Flexibility was measured using a modified Apley's Scratch test. Participants reached over and behind the head with the dominant hand and behind the back and up with the non-dominant hand. This was repeated in reverse and scores where measured based on the centimeters their hands failed to touch by (- scores) or by an overlap of their fingers (+ scores). Lower body flexibility was measured using an electronic flexometer in centimeters.
RESULTS: Both RT protocols were well tolerated with 98% adherence that resulted in significant increases in upper and lower body strength (p <.01). There were no significant between group differences on the three measures of flexibility from pre to post testing. However, a small non-significant increase in flexibility in the non-dominant arm and lower body did occur in the exercise groups. Non-dominant arm flexibility increased.58 cm, and lower body flexibility increased 2.3 cm.
CONCLUSIONS: Strength training in middle-aged women 3 or 4 days a week following ACSM guidelines will not alter functional flexibility. It is safe for middle aged women to perform strength training programs and not fear the development of muscle bound physiques or losing functional flexibility.