Strength training has 'strong' anti-depressive effect, even in healthy individuals

Strength training has a strong anti-depressive effect, even in individuals with a 'healthy' brain, a new study has shown. This article from Women’s Health, written by Kate Cheng, delves into the results from this study, which shows promising results.

The research investigated the effects of an eight-week strength-training program to reduce symptoms in young adults (55, to be precise, between the ages of 21 and 31) with and without generalised anxiety disorder and depression, and found a 'significant, clinically-meaningful, large-magnitude reduction in depressive symptoms' in all participants, including, notably, even those without anxiety disorder or depression.

This makes a promising case for the efficacy of resistance training as a potential treatment for mild depression.

What did the strength-training program involve?

The study's training program was designed following The World Health Organisation's (WHO's) and American College of Sports Medicine's (ACSM's) guidelines, where WHO recommends muscle-strengthening activities involving major muscle groups on two or more days per week, and NASM suggests progressive overload (gradually increasing the weight and/or number of reps of an exercise) on two to three days per week, with two to three sets of eight to 12 repetitions.

After a three-week introduction period to ensure safety and correct lifting technique, participants completed one-on-one strength-training sessions twice a week over eight weeks.

They engaged in progressive overload of usually about 5%, ensuring they could complete two sets of eight to 12 reps before their form suffered. If they failed, the load decreased by 5% in the following session.

The eight exercises used were: barbell back squat, barbell bench press, hex bar deadlifts, seated dumbbell shoulder lateral raise, barbell bent-over rows, dumbbell lunges, seated dumbbell curls, and ab crunches. Sessions lasted about 25 minutes and were fully supervised.

What were the results?

Depressive symptoms - which include low mood, loss of interest and or pleasure in activities, poor concentration, and disturbed sleep or appetite - were reduced among 39 participants (both with and without generalised anxiety disorder and depression) from baseline to week eight; increased among eight participants; and did not change among eight. If there were changes in strength, these weren't related to changes in signs of depression.

The antidepressant effect of resistance training is larger than previously reported for aerobic and resistance exercise.

This is the latest study to add to a growing body of research detailing the antidepressant effect of strength training.

One paper published in JAMA Psychiatry analysed 33 studies involving 1877 participants and found that resistance exercise 'significantly reduced depressive symptoms'. In one of the studies, the 947 participants in the intervention group performed resistance training approximately three times per week over an average of 12 weeks. It was found that individuals with mild to moderate depressive symptoms benefitted particularly.

Another meta-analysis looked at four studies, where groups were monitored for eight to 16 weeks. Training frequency was twice or or three times per week, with the duration of sessions lasting between 30 and 90 minutes. Free weights, machines and small equipment were used. Two of these studies showed that depression symptoms were greatly alleviated.