Value

Before we get into the cost of training, let's first establish the value. Why train? Without even going into the psychological benefits of improved body composition and confidence that come with training, physically, progressive strength training improves bone density in men and women of all ages in a way that running and traditional light weight training cannot match [1] [2] [3]. Not only has it been shown to improve glycemic control in patients with Type 2 diabetes [4] but also improves quality of life and function in old age [5] [6]. Both strength and muscle mass are consistently associated with lower overall mortality [7] and appear to be cardio-protective (heart-healthy) overall [8] [9]. Imagine a "magic pill" or a surgical intervention that had this kind of lifelong, positive impact on human health. People would likely wait in endless lines and empty out savings accounts to get it. There is no pill or surgery, and until that is developed training is the only way to get these physiological benefits. It goes without saying, but if you don't yet know how to train, then you need to hire someone who does.

The Typical Cost

Most independent personal trainers cost between $40-$60 per hour, with some ranging much higher. If you hire a trainer at a big-box gym or boutique studio you're going to pay closer to $70-$100 an hour.
Your body recovers from a workout within 36-48 hours. After your body is recovered, it adapts and gets stronger in case it meets the stress again. If no stress is introduced the body assumes it won't need to continue to adapt and will let go of the change.
This means you are either in a state of adaptation, maintenance, or detraining depending on the last time you trained. You can maintain progress training 1x per week and need to train 2-3x a week to see progress. If you cannot train on your own that can cost upwards of $4,000-$16,000 per year.

A different way of doing things

Not everyone can afford to pay thousands of dollars a year for a personal trainer, yet everyone needs to train if they want the benefits. As I talked about in my mission statement, I want to create independence in my clients. I am trying to kick clients "out of the nest" as soon as they are ready for it. This is accomplished by systematically integrating solo training sessions. Below is a simple example of how I would seek to do this with a new client.

What happens after you're self-sufficient and training on your own?

Once you are independent, all you need is good programming that is fun enough to adhere to and realistic to your schedule. Once you're reached an appropriate strength level, you can maintain that strength with minimal work.

There is no perfect training program

There is only a training program that is appropriate for you relative to your genetic potential. Until you reach a point that you're happy to maintain, your training program will need to change as you improve.
*Image from Mark Rippetoe's Practical Programming for Strength Training*

References

1. Andreoli, A., M. Monteleone, M. Van Loan, L. Promenzio, U. Tarantino, and A. De Lorenzo. “Effects of Different Sports on Bone Density and Muscle Mass in Highly Trained Athletes.” Medicine and Science in Sports and Exercise, 2001, 507-11. doi:10.1097/00005768-200104000-00001

2. Kelley GA., Kelley KS., Tran ZV. Resistance training and bone mineral density in women: a metaanalysis of controlled trials. Am J Phys Med Rehabil. 2001;80:65–77. doi: 10.1097/00002060- 200101000-00017.

3. Frost, H.M. “Why Do Marathon Runners Have Less Bone than Weight Lifters? A Vital-biomechanical View and Explanation.” Bone 20, no. 3 (1997): 183-89. doi:10.1016/s8756-3282(96)00311-0.

4. Castaneda C, Layne JE, Munoz-Orians L, et al. A randomized controlled trial of resistance exercise training to improve glycemic control in older adults with type 2 diabetes.Diabetes Care, 25(12):2335-41, 2002.

5. Liu CJ, Latham NK. Progressive resistance strength training for improving physical function in older adults. Cochrane Database Syst Rev3):CD002759. 2009

6. Savage P, Shaw AO, Miller MS, et al. Effect of Resistance Training on Physical Disability in Chronic Heart Failure. Medicine and science in sports and exercise. 2011;43(8):1379-1386. doi:10.1249/ MSS.0b013e31820eeea1.

7. Ruiz JR, Sui X, Lobelo F, et al. Association between muscular strength and mortality in men: prospective cohort study. BMJ 337:a439, 2008

8. Artero EG, Lee DC, Lavie CJ, España-Romero V, Sui X, Church TS, et al. Effects of muscular strength on cardiovascular risk factors and prognosis. J Cardiopulm Rehabil Prev. 2012;32(6):351–8. doi: 10.1097/HCR.0b013e3182642688

9. Ramírez-Vélez R, Correa-Bautista JE, Lobelo F, et al. High muscular fitness has a powerful protective cardiometabolic effect in adults: influence of weight status. BMC Public Health. 2016;16:1012. doi:10.1186/s12889-016-3678-5.