Strength: What, Why, How

Life puts our bodies through many physical forces and pressures. To withstand them, we need to be strong; to become strong, one must understand what strength is, why it’s important, and how to increase it.

Strength is defined in the Oxford Dictionary as the “quality or state of being physically strong” or the “capacity of an object or substance to withstand a great force or pressure” (8). How can we increase our “state of being physically strong”? We increase the amount of work we can do by increasing our ability to exert force. Scientifically, strength is defined as the ability to do work. Work = force x distance. Distance is the range of motion (ROM) e.g. limb length, distance the bar travels, etc. Force is the mass, or weight, we put on the bar or other piece of exercise equipment. By adding more mass, we get stronger.

Why is getting stronger important? As we age, being strong is extremely important. Frailty and weakness are major causes of complications in illness and hastens death among the elderly. Diseases like osteoporosis and sarcopenia can be mitigated and potentially be prevented by strength training (3).

In individuals not at risk for sarcopenia and osteoporosis, strength training, or as the research calls it “resistance training”, decreases the risk of all-cause mortality. “The meta-analysis showed that, compared with no exercise, resistance training was associated with 21% (hazard ratio (95% confidence interval (CI)), 0.79 (0.69-0.91)) and 40% (hazard ratio (95% CI), 0.60 (0.49-0.72)) lower all-cause mortality alone and when combined with aerobic exercise, respectively. Furthermore, resistance training had a borderline association with lower cardiovascular mortality (hazard ratio (95% CI), 0.83 (0.67-1.03))…One cohort study looked at the effect of resistance training on coronary heart disease events in men and found a 23% risk reduction (risk ratio, 0.77, CI: 0.61-0.98).” (9)

Another meta-analysis used handgrip and knee extension strength to assess men’s and women’s upper and lower body strength. “Thirty-eight studies with 1,907,580 participants were included in the meta-analysis. The included studies had a total of 63,087 deaths. Higher levels of handgrip strength were associated with a reduced risk of all-cause mortality (HR=0.69; 95% CI, 0.64-0.74) compared with lower muscular strength, with a slightly stronger association in women (HR=0.60; 95% CI, 0.51-0.69) than men (HR=0.69; 95% CI, 0.62-0.77) (all P<.001). Also, adults with higher levels of muscular strength, as assessed by knee extension strength test, had a 14% lower risk of death (HR=0.86: 95% CI, 0.80-0.93; P<.001) compared with adults with lower muscular strength.” (5)

In addition to health, increasing strength obviously improves performance. Remember that increasing the value of force increases the amount of work someone can do. A person who can do more work is more physically capable than the person who cannot. Who do you want to be on your football team, the guy who squats 135lbs or the same guy who now squats 315lbs? You can only pick one. In addition to this anecdote, the research supports this.

Several studies highlite the importance of strength training in athletics. One was a study of elite soccer players. The researchers made them squat, pull a weight sled, and do some plyometric training. They tested them using two countermovement jumps with sprints and a zig-zag test. After the training regimen, they improved their test performance (4). Another study, showed resistance training improves endurance runners’ performance (1). Resistance training can improve muscular power and sports performance. The researchers compiled data on adolescent athletes who lifted weights and found performance improvements. “There is sufficient evidence to conclude that resistance-training interventions can improve muscular power in adolescent athletes” (7). The vertical jump test (VJ) is often used to determine an athlete’s athletic ability/power. The researchers found Olympic weightlifting improved VJ performance (6). In order to become a better athlete, getting stronger, or in other words, doing more work, is a key component.

How does one become stronger? This requires increasing force. Context or the goal determines the type of training. Increasing mass of a 1 rep max (RM) or 10RM are very different adaptations but both require increasing force. The specificity principle dictates exercise and repetition selection. One should train by using the exercises and rep ranges which provide the greatest transfer to their sport/activity. For example, a bodybuilder’s goal is to increase their muscle mass for aesthetic purposes. In order to do this, these lifters must increase their ability to produce force. Exercise selection is oriented towards this goal and allows for quite a bit of variety as long as the performed exercises contribute to the goal. Rep ranges are generally in the 6-10 range. These have been shown to increase muscle mass the most and contribute towards the goal. In contrast, a powerlifter’s exercise selection is more strict. The squat, bench and deadlift are the competition exercises. Powerlifting training should be comprised mostly of these exercises and their close variations. In terms of rep ranges it does incorporate exercises in the 6-10 range during certain timeframes, aka blocks. However, reps in the 1-5 range will need to be included in later blocks.

Once the training context has been determined, it’s time to write a program. The key to any program is understand the SRA curve. Hans Selye developed the SRA model. SRA means Stress, Recovery, Adaptation. An organism who experiences a stress which doesn’t kill it, will recover from and adapt to the stressor. In strength training, stress is any form of work i.e. exercise type and number of, sets, reps, and weight. Managing stress is important for continual progress. Stress HAS to increase e.g. adding weight to the bar in 5lb increments. However, too much stress, e.g. too much weight on the bar, can cause overreaching, overtraining, and injury. Adding the right amount of increasing stress over time, aka progressive overload, is fundamental to any strength training program. Finding what works requires knowledge via experience and other forms of learning. Programming can be tricky business. It’s important to try different exercises and set/rep schemes to find what keeps increasing strength. There’s a somewhat delicate balance which must be found via trial and error.

Stress is balanced by recovery. Too much recovery and no progress occurs. Recovery from training sessions means getting enough sleep, eating properly, and eating enough. Everyone should get 7+ hours of sleep a night (2). Nutrition plays an extremely important role in recovery as well. Macronutrients (macros) are protein, carbohydrates (carbs), and fat. A healthy person should have a BMI of 18.5-24.9 and waist circumference less than 40in. for men and 35in. for women (10). Potential starting points for macro amounts follow. Protein intake should be 1g of protein per lb of bodyweight (BW), 2g of carbs per lb of BW, and .5g of fat per lb of BW. Using a diary, like myfitnesspal, is necessary to making sure calories and macros are met. Foods to consume to meet these goals are single ingredient foods that once had eyes or grew in the ground. Lean meats like chicken, fish, beef, some cuts of pork and fruits, vegetables and some grains should make up the majority of one’s diet, no matter the goal. They should be unprocessed or minimally processed. E.g. steak is minimally processed whereas summer sausage is highly processed. This is a good start for increasing muscle mass. However, less can be eaten and recovery can still occur. These macronutrient recommendations may not be appropriate for everyone and are anecdotal. They represent examples but are basics for almost every nutrition program. The most important thing of any nutrition program is being able to stick to it. If one is recovering properly from their stressors by sleeping and eating properly, they will adapt. In this context, they will get stronger.

If the stress is increased in manageable amounts and the means of recovery are adequately met, adaptation will occur. Adaptation to the stresses in this context mean getting stronger. It doesn’t matter if your goals are powerlifting or general strength training. If they’re bodybuilding or increasing muscle just a little bit. All require increases in strength. This takes time but adaptation will occur if stress and recovery are made.

In summary, getting stronger means increasing one’s ability to produce force in a given context, thereby increasing their ability to do more work. Increasing work is incredibly important for health and performance. Force is increased via the SRA curve. Stress and recovery will result in adaptation. The goals of the athlete will dictate the context. Context will dictate programming. Gaining strength is inevitable under this formula.

References

1.Alcaraz-Ibañez M, Rodríguez-Pérez M. (2018). Effects of resistance training on performance in previously trained endurance runners: A systematic review. J Sports Sci. doi:10.1080/02640414.2017.1326618.

2. American Academy of Sleep Medicine and Sleep Research Society. (2015). Recommended  Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep.

3. Chang KV, Chen JD, Wu WT, Huang KC, Hsu CT, Han DS. (2018). Association between Loss of Skeletal Muscle Mass and Mortality and Tumor Recurrence in Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis. Liver Cancer. 7(1):90-103. doi: 10.1159/000484950.

4. de Hoyo M, Gonzalo-Skok O, Sañudo B, Carrascal C, Plaza-Armas JR, Camacho-Candil F, Otero-Esquina C. (2016). Comparative Effects of In-Season Full-Back Squat, Resisted Sprint Training, and Plyometric Training on Explosive Performance in U-19 Elite Soccer Players. J Strength Cond Res. doi: 10.1519/JSC.0000000000001094.

5. García-Hermoso A, Cavero-Redondo I, Ramírez-Vélez R, Ruiz JR, Ortega FB, Lee DC, Martínez-Vizcaíno V. (2018). Muscular Strength as a Predictor of All-Cause Mortality in an Apparently Healthy Population: A Systematic Review and Meta-Analysis of Data From Approximately 2 Million Men and Women. Arch Phys Med Rehabil. doi: 10.1016/j.apmr.2018.01.008.

6. Hackett D, Davies T, Soomro N, Halaki M. (2016). Olympic weightlifting training improves vertical jump height in sportspeople: a systematic review with meta-analysis. Br J Sports Med. doi: 10.1136/bjsports-2015-094951.

7. Harries SK, Lubans DR, Callister R. (2012). Resistance training to improve power and sports performance in adolescent athletes: a systematic review and meta-analysis. J Sci Med Sport. doi: 10.1016/j.jsams.2012.02.005.

8. Oxford Dictionary, (2019). https://www.lexico.com/en/definition/strength

9. Saeidifard F, Medina-Inojosa JR, West CP, Olson TP, Somers VK, Bonikowske AR, Prokop LJ, Vinciguerra M, Lopez-Jimenez F. (2019). The association of resistance training with mortality: A systematic review and meta-analysis. Eur J Prev Cardiol. doi: 10.1177/2047487319850718.

10. U.S. Department of Health & Human Services. (2019). Assessing Your Weight and Health Risk. https://www.nhlbi.nih.gov/health/educational/lose_wt/risk.htm