The client was 58 and very fit. She was wearing a pulse meter on her wrist. Ninety seconds into the workout her pulse was 148 which is approaching her maximum for a person her age.
One method of determining one’s maximum heart rate is to subtract one’s age from 220 bpm. Using this method this client’s maximum heart rate would be 162 bpm.
We began the workout with the leg press using a heavy weight and slow initial movements. The leg press involves large muscle groups and can get one’s heart rate up in short order. The slow starts minimize force associated with injury and allow one to warm up safely with the heavier weights. The warm up is in effect incorporated in to the first set using a challenging weight. After a minute she was breathing hard and I told her to move faster. At this point her muscles were warmed up and appreciably weaker. Warmed-up weaker muscles are unlikely to generate enough force to cause injury as long as good form is maintained. Her attempts to move fast did not amount to much at that point in the set, but it did allow her to keep moving and achieve a deeper fatigue.
One of the goals or strength training is to expose the muscles to more work that they are used to handling. Performing a set in the manner can safely achieve that end. In most instances there is really no need to sap one’s energy to do a duplicate set. Effort, energy, and concentration can be devoted to the next exercise or muscle group.
Upon completion of the set she quickly moved on to the next exercise. Everything is pre-set; there is no need to dawdle. There is often a lot of standing around in a gym. Often times there is more time resting between sets than there is actually exercising. Not so with High Intensity Interval Training, HIIT. This is the type of training we do at both of our facilities -New Orleans Fitness Training and PersonalTraining in Austin.
As self protection the body adapts to the demands placed on it if given adequate time to recover. In her case she came back stronger and more able to withstand the sustained cardio demands. People of any age can do this workout and can build up to at their own pace. Our oldest client is 93 years old.
More information on the subject of cardio and strength training:
Cardio, anaerobic, and aerobic exercise explained
Blog entries regarding the heart healthy benefits of strength training