RESEARCH REVIEW: hanging, not always a punishment?
Researchers gauge the numerous physical effects of this popular form of bodyweight training.
Title: Physiologic and metabolic effects of a suspension training workout
Author: Drs Dudgeon and colleagues. (Dept of Health & Human Performance, College of Charleston/Citadel, South Carolina, USA)
Source: International Journal of Sports Science (2015). Volume 5(s), pp 65-72. Available free online: article.sapub.org/10.5923.j.sports.20150502.04.html
Introduction: The health and fitness industry is a vibrant, continually evolving one. We never fail to be amazed by the new trends in equipment, nutrition/diets and, of course, training techniques. Admittedly, a number (quite a number actually) of training fads have come and gone over the years, and no doubt this will continue well into the future. Those that stick around tend to be the ones that have scientifically proven benefits. One type of training that is of high interest is cross training, not the original concept of training for two or more sports, rather the type of training that includes an ‘all body’ focus and stresses a number of different components of fitness in the same workout. A significant portion of fitness enthusiasts are, unfortunately, time-poor and always looking for a novel and effective technique to train all the entities of fitness (cardiovascular, muscular strength, muscular endurance, muscular power and flexibility) in a single workout. This leads us to the topic of this Research Review: the benefits or otherwise of suspension training.
First, a brief history of this training: the term ‘suspension training’ initially referred to a system of ropes or webbing that allowed its practitioners to use their own bodyweight as the resistance. An ex-Navy seal, Randy Hetrick, is credited with developing this concept back in the 1990’s, when it was referred to as Total Resistance eXercise, now simply known as TRX. This evolved into the suspension training we know today, in which a two-strap system is used. This type of training (if you are unfamiliar) often comprises a series of exercises completed in a circuit fashion (for example 1:2 work-to-rest ratio, i.e. 30 seconds of exercise followed by 60 seconds of rest) which means minimal rest between exercises and resistance training movements which are both prolonged static and/or dynamic exercises. Suspension training circuit workouts are generally approximately 30 or 60 minutes duration. Given the popularity of this type of training, Dr Dudgeon and his colleagues chose to investigate its benefits.
Methods: A total of 12 active, trained male subjects in their early 20’s (mean body fat 13.6 per cent) volunteered to participate. All participants received two training sessions to familiarise themselves with suspension training and learn how to complete the 23 selected exercises. These covered a range of major movement patterns, involving most of the major muscles. A heparinised catheter was placed in each subject’s forearm to attain blood samples to assess blood lactate; a metabolic cart was used to assess expired gases for oxygen consumption (VO2) and caloric expenditure (kcals); while heart rate was determined using a telemetry heart rate monitor.
Results: The participants’ heart rate at rest was (on average) 70 bpm, however this rose significantly (p<0.05) to 127 bpm mid-exercise and slightly higher to 129 bpm post-exercise. The average heart rate, expressed as a percentage of age-predicted HRmax, was approximately 74 per cent for the group. Systolic blood pressure also rose significantly from rest (121 mmHg) to mid-exercise (134 mmHg), whereas diastolic blood pressure actually decreased significantly (p<0.05) from rest (79 mmHg) to mid-exercise (68 mmHg).
Blood lactate increased significantly (p<0.05) from 0.9 mmol/L at rest to 8.0 mmol/L mid-exercise, and returned to normal two hours post-exercise. Oxygen consumption (VO2) at mid-exercise was approximately 4-fold higher than at rest, caloric expenditure was 5.4 kcals/minute (~340kcals per session for the 60-minute exercise session).
The authors concluded that the suspension training routine they investigated equalled a moderate intensity workout (according to the American College of Sports Medicine guidelines) and there was only a ‘modest’ decrease in heart rate observed during the 60-second rest period. They further concluded that suspension training is suitable for most adults and is a simple and effective way to instigate cardiovascular adaptations and caloric expenditure.
Pros: This is a good initial investigation assessing the response to a single session of suspension training. The next logical study would be to conduct a longitudinal study (16 weeks) in which participants are assessed initially and at weeks 8 and 16 to determine any improvements in cardiometabolic parameters (resting heart rate, resting blood pressure and lipid profile (cholesterol)).
Cons: Although the authors made pre, mid and post-exercise measurements, it would have been beneficial if these measurements were also made just prior to the conclusion of the exercise session. Additionally, the authors claim that suspension training is a combination of unique training movements aimed at improving flexibility, though it is not apparent where this was incorporated into the workout.
Associate Professor Mike Climstein, PhD FASMF FACSM FAAESS is one of Australia’s leading Accredited Exercise Physiologists and researchers. firstname.lastname@example.org
Joe Walsh, MSc is a sport and exercise scientist. As well as working for Charles Darwin and Bond Universities, he is a director of Fitness Clinic in Five Dock, Sydney. fitnessclinic.com.au