Melis “Mel” Edwards, MS, creator of the H.I.T. Method™ (Hydrofit Interval Training), has spent the past 20 years promoting water fitness training both for athletes and as an athlete herself. Edwards, group fitness instructor and director of admissions at Montana State University in Bozeman, Montana, has trained both professional and recreational athletes.
Case in point, Kelcie Nice, a 33-year-old Ironman® athlete and resource engineer, was training for her first Ironman when she developed a hip imbalance. Nice discovered Edwards and trained entirely in the water for 2 months until the problem was corrected. For the next 4 months until the race, she continued hydrotraining 2–3 times per week. “I’m now a lifetime proponent of water running and walking proof that it is not only a legitimate alternative to land running but could possibly even be the way to go,” she says. “There’s no doubt that [land] running, and the constant impact that it delivers, is not easy on the body, no matter how addicting those endorphins may be.”
Water fitness has come a long way from its origin story of older women in shower caps having fun in the local pool. Ken Baldwin, director of education at Perform Better Australia, in Brisbane, Australia, says, “Aqua is the ‘go-to’ method of recovery for all Australian Football Rules teams—rugby and soccer. If they can’t get to a cold-water beach, they’ll go to an ice pool to do their walking and regeneration and recovery moves. All professional sporting teams [in Australia] are using water training from that perspective.” Experts agree that interest in deep water running and aquatic boot camp is increasing.
This article examines what’s new in aquatic training research, what’s changing in water fitness class demographics and which program trends are growing. Higher-intensity training and recovery continue to be popular throughout the fitness industry, and aquatic exercise provides options for both. If you’re looking to expand your training repertoire, check out this new wave of possibilities.
Mounting research on the benefits of aquatic exercise is changing its image and supporting the claim that it helps people of all ages and ability levels. Before diving into the research, it’s good to review why water is a complementary training medium to weight-bearing, land-based activities. For more on this, see the sidebar “The Properties of Water.”
The gold standard in research is the randomized controlled trial, but owing to lack of funding, few such trials exist in aquatic research, according to experts. Mary E. Sanders, PhD, FACSM, adjunct professor/specialist in internal medicine at the University of Nevada, Reno, school of medicine, and adjunct professor at the university’s school of community health sciences, says, “Many of us would like to see [research] protocols described better by investigators, with more emphasis on studies that extend for longer periods of time . . . If a study is published in a scientific journal or presented at a scientific meeting with peer review, then it needs to be considered. Many studies have low numbers of exercisers, examine unrealistic exercises or do not take into consideration the properties of water, which perhaps may have changed their conclusions.”
Here are some of the newer findings related to aquatic training, as identified by researchers involved in peer-reviewed studies.
Aquatic training improves ability to perform activities of daily living (ADL). The effectiveness of functional aquatic training for older adults seems well-established. Older women who participated in 60-minute shallow-water exercise classes 3 days a week for 12 weeks performed better in land-based ADL, but did not improve balance (Sanders et al. 2016). The Golden Waves® program, used in this and other studies, has proved effective in all variables except for balance, which has had inconsistent results. Sanders notes that for balance improvement, water depth is critical and shallower is better. “When water is armpit depth, it seems there’s not enough gravity ground-force reaction to challenge balance somatosensory systems (feet),” she says. See the “Resources” sidebar for additional information.
Water fitness enhances muscular strength and endurance, increasing lean body mass. Evidence shows that people of all ages and ability levels can improve strength, endurance and body composition through effective aquatic training. Postmenopausal women who trained with aquatic resistance equipment twice a week for 10 weeks gained strength, reduced fat and increased lean body mass as effectively as women who used weight machines and exercise bands in equivalent programs (Colado et al. 2012).
Fit young men who did a periodized strength training program 3 times aweek for 12 weeks significantly improved muscular strength and power and increased lean body mass (Colado et al. 2009). Healthy, untrained older women who did 60 minutes of shallow-water exercise (including 20 minutes of upper- and lower-body resistance training with equipment) 3 days a week for 24 weeks increased lean body mass by 3.4% and significantly improved muscular strength (Tsourlou et al. 2006).
Water exercise can meet cardiovascular fitness metrics. New research is settling the debate about whether upright water training is an effective way to cross-train for better cardiovascular fitness. Sanders points to recent research (she was a co-author) that showed that cardiovascular training in water is effective when appropriate protocols, speed and movements are employed. Unskilled healthy young women met ACSM ranges for cardiovascular training in a 40-minute shallow-water session while using resistance gloves. The “hover jog” achieved the greatest average intensity, at 7.3 METs (Nagle et al. 2013).
Water ameliorates running performance. In a study that compared electromyography (EMG) activity between dry-land and deep-water runners, researchers found similar but not identical muscle recruitment and concluded that, for healthy individuals, maximal velocity optimized neuromuscular responses in the legs (Alberton et al. 2015). Researchers noted that deep-water running (DWR) reduced ground-force impact by up to 85%.