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.