minimum effective dose

Exercise that will strengthen tendons and connective tissue


Too much tendon stress results in tears and overuse conditions such as tendinitis. These injuries often occur as a result of exercise. Injuries sustained in the pursuit of fitness can come back to haunt you.  They present themselves as nagging aches and pains that compromise your fitness as you get older. 

One of the objectives of exercise is to prevent injuries, not cause them. Proper strength training, by increasing bone density and muscle strength, gives one an added measure of protection from injuries. The same applies to tendons and other connective tissue - “Research indicates that resistance training promotes growth and/or increases in the strength of ligaments, tendons, tendon to bone and ligament to bone junction strength, joint cartilage and the connective tissue sheaths within muscle”.1

To minimize risk of injury, the goal is to exercise enough to produce positive change in your your muscles, joints, and connective tissue, not to see how much stress they can withstand . At our Austin Strength Training facility, we have years of experience determining the minimum effective dose of exercise (the amount that safely produces ongoing optimal improvement). Anything beyond that will at best result in a diminishing marginal return and at worst result in injury.

If you do nothing your muscles, bones, and connective tissue will become weaker and make an injury more likely. Is it worth a half hour of strength training each week to help avoid injuries and to live an active life?  We think it is.


36 minutes of vigorous exercise over 5 1/2 months, the results.


To get more out of exercise it is essential to accurately determine the minimum effective dose and the amount of recovery time needed to produce improvement.  Perry, age 69, does his weekly 30 minute strength training sessions at our Austin strength training facility.  He recently began sprint training on one of our stationary bikes about three times a month. 

For the strength training we measure Perry’s time under load (TUL) for each exercise.  When the TUL increases to a certain point we raise the weight the next session.  Perry has been training for four years and continues to improve.  We keep accurate records.

We do the same for sprint training. To accurately measure improvement we control the variables:

  • ·         Same difficulty level

  • ·         Same number of sprints(6)

  • ·         Same sprinting interval (22 Seconds)

  • ·         Same recovery level (heart rate) before beginning the next sprint.

In May it took Perry 28 minutes to do six sprints.  Five and half months later his time had gone down to 18:30 minutes. That is a 9 ½ minute improvement - the same work in far less time.  Adding up all the twenty-two second sprints that comes out to a total of 36 minutes of sprinting time over 5 ½ months.

With 330,000 workout sessions under our belts working with a wide range of ages and abilities, we have a good idea of what constitutes an effective dose of exercise (it is not that much) and the recovery time needed to produce ongoing improvement.The sprints are demanding - that is what stimulates change – but the time commitment is small, and the benefits are worth it.



Study shows how people waste time exercising

In a study, one group lifted weights for nine weeks (Continuous resistance training – CRT), while another group lifted for six weeks followed by a three weeks rest (Periodic resistance training - PTR). After the first nine week cycle the groups’ results were similar. The cycle was repeated for nine more weeks, and PTR group’s results were significantly higher.

A quote from the study, Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training: “Increase in muscle cross-sectional area [of muscle] and strength during the second 3-week detraining/6-week retraining cycle were significantly higher in the PTR group than in the CTR group.” Consider that CTR group trained six weeks more and achieved inferior results - wasted time and effort.  

At the end of 27 weeks, both groups’ results were similar, but continuous training group trained six extra weeks to get that same result. If you start from the premise of finding out how little exercise you actually require your marginal return for your time in the gym will be higher and you will be less likely to over-train. When rest is inadequate over-training results and improvement stops. At Austin Personal Trainers and New Orleans Personal Trainers we take great care in measuring exercise performance to be sure that the client is fully recovered. With full recovery you will continue to improve.