ACUTE EFFECT OF HEAVY WEIGHTLIFTING ON THE PELVIC FLOOR MUSCLES - AN EXPERIMENTAL CROSSOVER STUDY

K.L. Skaug¹, M.E. Engh², K. Bø¹

¹Norwegian School of Sport Sciences, Department of Sports Medicine, Oslo, Norway, ²Akershus University Hospital, Department of Obstetrics and Gynaecology, Lørenskog, Norway

Background: Strenuous work and heavy lifting have been proposed as risk factors of pelvic floor dysfunction in women due to the increases in intraabdominal pressure and possible strain on the pelvic floor. Further, urinary and anal incontinence is commonly experienced among female weightlifters and powerlifters.

Purpose: The purpose of the study was to investigate the acute effect of heavy weightlifting on pelvic floor muscle (PFM) strength, resting pressure, and resting activity in strength trained women.

Methods: In this experimental randomized crossover study we included nulliparous women between 18-35 years who regularly performed strength training and were able to lift their own bodyweight x 1.2 in squat and 1.5 in deadlift. Participation included baseline evaluations (questionnaire of urinary incontinence (ICIQ-UI-SF), height, weight, 1 repetition maximum (1RM) tests in squat and deadlift) and one experimental day where the participants were randomized to start with either strength training (4x4 repetition at 75-80% of 1RM in squat and deadlift) or rest (in sitting position for 60 min). The PFM were measured before/after training and rest and included vaginal pressure measurements of resting pressure (cm H2O) and strength (maximal voluntary contraction in cm H2O) and sEMG-measurements of resting activity (microvolt, µV). We estimated that at a sample size of at least 42 were required to provide statistical power.

Results: Fourteen powerlifters, 4 Olympic weightlifters, 13 CrossFit exercisers and 15 recreational exercisers were included (N=46). Two were not able to attend the experimental day. Twenty-two (47,8%) reported any type of urinary incontinence. The most common type was stress urinary incontinence (involuntary leakage of urine on physical effort, coughing and/or sneezing), reported by 19 (41,3%). Mean PFM strength was 24.0 cmH2O (SD: 11.0), resting pressure 28.8 cmH2O (SD: 5.9) and resting activity 12.6 µV (SD: 8.8). There were no statistically significant correlations between PFM strength and maximum (1RM) or relative strength (1RM/bodyweight) in neither squat nor deadlift. We used paired t-tests to compare mean change in PFM strength, resting pressure and resting activity after strength training and rest. No statistically significant differences were found. Only 3 of the participants reported minor urinary leakage during the training session.

Conclusions: We found that heavy weightlifting, including squat and deadlift of 75-80% of 1RM, had no immediate effect on the PFM compared to rest in strength trained, nulliparous women. PFM strength was not correlated with either maximal strength or relative strength in squat and deadlift.

Implications: Although heavy weightlifting exercises (e.g. squat and deadlift) are assumed to produce strain on the PFM due to increases in intraabdominal pressure, our results imply that these exercises are well tolerated by the PFM in healthy, nulliparous women with experience in strength training. Since pelvic floor dysfunction is common among female powerlifters and Olympic weightlifters, long term effects of heavy weightlifting and lifting above 80% of 1RM should be further investigated. Our sample included healthy, nulliparous women with no or mild pelvic floor dysfunctions and studies comparing effects of heavy lifting on the pelvic floor in women with and without dysfunction or nulliparous vs. parous women are therefore of interest.

Funding acknowledgements: This was a university initiated and conducted study. There was no extra funding.

Keywords:
Pelvic floor
Female athlete
Women's health

Topics:
Pelvic, sexual and reproductive health
Sport & sports injuries
Musculoskeletal

Did this work require ethics approval? Yes

Institution: Norwegian School of Sport Sciences

Committee: The Regional Committees for Medical and Health Research Ethics (Sør-øst B)

Ethics number: 2018/2211