Involuntary loss of urine can occur if a woman is unable to effectively activate her pelvic floor muscles to counteract an increase in intra-abdominal pressure. Lifting an external weight has been shown to increase intra-abdominal pressure. Consequently, women are sometimes advised against participating in resistance exercises, particularly exercises such as wide legged, deep squats, or deadlifts.

The aim of the study was to investigate the effect of twelve weeks progressive resistance training on the strength of pelvic floor muscles and the severity and frequency of urinary incontinence in healthy untrained women.

Eighteen nulliparous and mixed parity women, with no or mild-to-moderate urinary incontinence and no previous experience in regular resistance-training, volunteered to participate in this pre-experimental one group pre-test post-test study. Frequency and severity of UI was measured before and after the intervention using the Incontinence Severity Index tool. Furthermore, the strength of pelvic floor muscles, and physical parameters including body composition and maximum strength were carried out before and after the intervention. 

Participant’s ability to effectively contract their pelvic floor muscles was assessed using Perineometry and palpation. The tension and maximum strength of participant’s pelvic floor muscles was assessed at rest and during maximal contraction in a supine position using vaginal pressure probes connected to a Peritron perineometer. 

Body composition of participants was assessed using a segmental body composition analyser (TANITA BC-418, TANITA, Japan). Maximum strength was assessed following a 5 Repetition Maximum (5-RM) protocol in seated leg press and lateral pull-down. Upper body strength was assessed during maximum incline pull-ups and push-ups on knees. 

Exclusion criteria included history of bladder surgery, active urinary tract infection, experience in resistance training and/or an inability to effectively activate the pelvic floor muscles during their assessment by a women’s health physiotherapist. Three women were excluded from the study; two women did not complete 80% of the training sessions and the other was injured during other recreational activities. 

The intervention consisted of a twelve-week progressive resistance training program including back squats, deadlifts, push-ups, and incline pull-ups. The participants completed two training sessions per week under the supervision of a qualified powerlifting coach. Individual assistance exercises were recommended by the coach and implemented to develop the participant’s mobility, flexibility and stability. Each training session started with warm-up exercises including hip mobility, hamstring and quadriceps flexing for a full range of motion, followed by stability work and individualised assistance activities. Specific warm-up exercises included 2-3 sets of squats and deadlifts with a progressive load until participants reached their working weight. The working weight consisted of 3 sets of 10 repetitions in the first week; this was reduced to 2 sets of 2 repetitions in week twelve in response to increasing intensity. The rest period between the working sets was five minutes, increasing to twelve minutes in the final week. Correct breathing and bracing techniques were practised with emphasis on the activation of pelvic floor muscles during a lift using the pebble analogy. Following lifting, 3 sets of 10 push-ups and incline pull-ups were completed, and each session was finished with a cool-down including stretches and foam rolling.

Due to the small sample size of the study, and violation of the normal distribution of data, a Wilcoxon Signed Rank Test (WSRT) was used to assess the effect of resistance training on urinary continence and physiological changes. The probability level of statistical significance was set at p ≤ 0.05, and descriptive statistics were expressed as means ± SD. Effect size (ES; Cohen’s d) was calculated to examine the magnitude of differences in the dependent measures before and after the intervention, with 0.2 considered as a small ES, 0.5 as a moderate ES and > 0.8 as a large ES (1).

A statistically significant reduction was observed in the frequency of urinary incontinence, but there was no statistically significant effect on the severity of urinary incontinence as measured by the Incontinence Severity Index. There was a significant increase in maximum pelvic floor strength and physical strength, but no correlation was found between pelvic floor strength and urinary incontinence. A strong positive effect of resistance training on urinary incontinence was demonstrated in ten out of twelve women who reported some level of urinary incontinence prior to commencement of the training program.

The exact mechanisms responsible for a reduction in the frequency of urinary incontinence experienced by the participants are not fully understood. However, increased pelvic floor strength and an improved ability to counteract intra-abdominal pressure during physical stress may have resulted in less frequent leakage. Anecdotally, participants reported applying techniques learned during training sessions, such as activating their core and pelvic floor muscles prior to lifting, to everyday activities like sneezing, coughing and picking up the shopping or washing. It is possible that an improvement in the ability to consciously activate the pelvic floor muscles in a timely manner resulted in a decrease in the frequency of urine leakage. In addition, an improvement in overall strength and an increase in fat free mass, especially in the abdominal area, may also have contributed to a reduction in the incidence of urinary incontinence.

The results from this study suggest that resistance exercises can improve the strength of pelvic floor muscles and reduce the frequency of urinary incontinence in women. Additionally, resistance training provided valuable health benefits to the participants of this study. Further research into the relationship between urinary incontinence, pelvic floor strength and resistance training is warranted.

Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences. New York, NY: Routledge Academic.