When designing exercise programs, we often focus on both aerobic and strength training components. But how do we determine the right intensity for each individual? Physical therapists working with athletes aim to find the optimal level of intensity for strength training, ensuring it’s neither too much nor too little. This blog will explore evidence-based approaches to exercise prescription and offer a useful tool to improve precision when making exercise recommendations.
Exercise prescription involves key factors such as volume, exercise density, and intensity. Volume refers to the duration of exercise, including sets and repetitions, while exercise density compares the amount of work completed to the rest periods.1 Ideally, this ratio can be self-regulated by the patient, both subjectively and objectively.2 For example, an unconditioned individual may need several minutes of rest after doing lunges, while a more conditioned person may only require 30 seconds. The unconditioned person might rate their effort as 8/10 in difficulty, while the conditioned person might rate the same activity as a 3/10. This subjective perception can also be compared with objective measures, like heart rate, to more accurately assess the difficulty of the exercise.
Physical therapists can play a vital role in guiding athletes through the correct dosage of volume, density, and intensity in their exercise routines. Unfortunately, underdosing is common in clinical practice.3 A frequent issue is the unmodified use of the classic “3 sets of 10 repetitions,” which often lacks the necessary customization for individual progress. Research, such as Holten’s curve, suggests determining an athlete’s one-repetition maximum (1RM) for more precise exercise dosing.4 In 1945, DeLorme suggested using 3 sets of 10 repetitions but emphasized that progressive loading is essential for maximizing strength gains. However, this concept of progressive overload is often overlooked.
One helpful tool to assess intensity is the OMNI-RES scale.6 This simple scale helps determine how many repetitions an athlete has left in reserve before reaching exertion, offering insight into whether the load can be increased.
There are multiple ways to adjust exercise intensity, including increasing load, volume, or changing exercise order. Load refers to the weight being lifted, and volume is the total number of repetitions across a session.5 Changing the order of exercises can introduce variety and challenge the athlete in new ways. Strength progression can also be achieved through various methods, such as increasing load, volume, or the number of exercises, or by adjusting rest times and repetition speed.5
We would suggest focusing on the athlete’s perceived exertion and asking how many repetitions they have left during resistance training. This approach has been shown to enhance maximal strength by considering daily fluctuations in an athlete’s fitness, fatigue, and readiness.
The OMNI-RES scale provides an easy way to gauge intensity and track when an athlete should increase resistance. Using a scale from 0-10, the athlete rates the difficulty of their exercise. If they can perform 3 sets of 15 repetitions with an OMNI-RES score below 5, it’s time to increase the resistance, whether through weights, tubing, or bands. The athlete’s intensity should then be reassessed using the same scale to ensure the appropriate challenge.
Despite its effectiveness, the OMNI-RES scale is not commonly used in clinical settings. Many clinicians rely on habit or clinical impression when selecting resistance levels rather than using evidence-based tools. As physical therapists, we need to prioritize excellence in the care we provide. This means reflecting on how we prescribe exercise and ensuring we communicate effectively with our patients. Why is it commonplace to ask patients about their pain levels, yet we often overlook quantifying their effort and intensity during exercise?
As a clinician and educator, I believe it’s crucial to use evidence-backed tools like the OMNI-RES scale to better dose exercise for athletes. This tool offers a validated, objective way to assess subjective effort, yet it’s still underused in practice.6,7
At Southern Spine & Sport, we are committed to improving exercise prescription for our patients, especially athletes. By focusing on individualized, evidence-based exercise dosing, we can help athletes reach their full potential through more precise and effective training.