Muscular strength is defined as the ability to exert a force on an external object or against some type of resistance. Strength may be expressed when hitting a baseball during sport or when standing up from a low chair during everyday life. Strength is required to press a loaded barbell overhead or strength may be needed to carry groceries from the car into the home. Optimizing strength across the lifespan can have profound effects on athletic performance, quality of life, health, and longevity.
Strength & Sports Performance
During sport, athletes exert large forces against gravity (i.e., sprinting or gymnastics), against an opponent (e.g., football) or when manipulating an object (e.g., throwing a baseball). Muscular performance can be a limiting factor in performing any of these athletic endeavors. Power refers to the rate at which force is produced. Stronger athletes produce more force and often do so in much less time. Power is associated with several important sport variables such as sprinting speed, jumping, change of direction, and throwing velocity. Improving muscular strength through resistance training is a sure fire way to improve power and subsequent sports performance.
An athlete’s ability to run, jump and change direction is crucial for success in most sports. Enhancing muscular strength improves these characteristics which often transfer to sport specific skills during competition. Stronger athletes jump higher and further than weaker athletes. Strength may be expressed when an athlete elevates for a rebound in basketball, jumps to spike a ball in volleyball, or dives to catch a ground ball in baseball. Athletes, who produce large forces on the ground, are able to jump higher and further than weaker athletes. This results in a true competitive advantage in many sports.
Stronger athletes are also able to accelerate running speeds over short distances. Elite athletes are able to produce greater forces, with short ground contact times, and with greater stride lengths compared to non-elite athletes. Evidence strongly suggests a correlation between maximal strength and running speed1. Athletes who produce greater amounts of force over a shorter period of time are able to change direction at greater velocities. This is important in basketball or football when attempting elude defenders. Becoming stronger is a no-brainer for any athlete looking to jump higher, run faster, or rapidly change direction during their sport. Lateral lunge variations are an excellent way to improve strength in the frontal plane where many athletic injuries occur.
Strength transfers to performance in both strength-power sports and endurance sports. Stronger cyclists are faster than weaker cyclists. Handball players with greater strength outperform weaker handball players. Stronger sprinters have faster 100-meter times than weaker sprinters. Stronger baseball players possess greater bat speeds and throwing velocities than weaker players. Strength alone does not ensure athletic success, but the evidence is compelling that stronger athletes possess a competitive advantage over weaker athletes in most sports.
Strength & Quality of Life
There has been a steady decline in fitness and muscular strength in children and youth across the world. Research shows greater muscular fitness in school-aged youth (4-19 years)is associated with improved body composition (e.g., decreased body fat), and improved risk factor profiles for heart disease and diabetes2. There is also strong evidence for a positive association between muscle strength and bone health and self-esteem in children2. Therefore, youth physical activity programs which promote muscular strength can have many benefits related to overall health and quality of life.
Sarcopenia refers to the age-related loss of muscle size and strength in older adults. Loss of muscle mass begins at approximately age 25 and progresses to a loss of 30% or more by the age of 80. Loss of muscle mass occurs primarily in type II muscle fibers which are highly responsible for muscle strength and power. Therefore, the rate and magnitude of strength loss usually exceed that of muscle mass by 2-5 times.
Age-related loss of muscle strength and bone mass (osteopenia) are associated with impaired functional mobility, compromised balance, and increased risk of arthritis, joint replacement surgeries, falls, and fractures. All of these factors can substantially diminish the quality of life. Nearly 20% of women and 10 % of men over the age of 65 cannot lift a 10-pound weight or kneel down on the floor. The age-related loss of strength is also associated with an inability to live independently and premature death3.
Maintaining muscle strength is a key strategy that leads to healthy aging. Sedentary behavior and physical inactivity are key drivers of sarcopenia and can accelerate the loss of muscle mass and strength. Maintenance of physical activity and engagement in a regular strength training program can diminish or even prevent these age-related changes. Pulling exercises or row variations are great for strengthening the upper body and core musculature.
The Importance of Strength for Optimal Health & Longevity
It is well-known that aerobic fitness is associated with decreased risk for chronic disease and premature death. The health benefits of exercise programs which target muscular strength is less known to the general public. A 2017 study published in the American Journal of Epidemiology showed resistance training reduced the risk of all-cause and cancer-related death to a greater degree than aerobic exercise4. There is now a growing body of evidence suggesting poor muscular strength is associated with death from all causes in both healthy and diseased populations
Another review in the European Journal of Internal Medicine reported a reduced risk for all-cause mortality with increased levels of muscular strength5. This association persists even after controlling for age, body fat, smoking, alcohol intake, medications, other health conditions, physical activity, and levels of cardiorespiratory fitness. Handgrip strength has been associated with survival and long-term outcomes in patients with cancer. Muscular strength has also been shown to be associated with long-term outcomes in patients with heart disease.
The health and mortality benefits of muscular strength appear to be related to multiple physiological mechanisms. This includes improved blood pressure, blood lipids, and body composition. Reduced systemic inflammation and reduction in insulin resistance have also been linked to improved muscular strength and mortality. Based on the available evidence showing a strong association with muscular strength and mortality, adults should perform muscle-strengthening exercises at least 2 days per week in order to reduce mortality risk. For most, basic lower body exercises such as squats and hip hinges are great places to start with a strengthening program.
We continuously perform activities during sport or our daily routine which require the expression of muscular strength. To a certain extent, muscular strength can be inherited. However, strength will never be optimized and will ultimately decline with age unless strength promoting exercises are undertaken. Optimizing or preserving muscular strength is strongly associated with improved sports performance, improved quality of life, improved physical function, reduced risk for chronic disease, and reduced risk for all-cause death. This should be sufficient evidence for all individuals, regardless of age or health status, to engage in some form of resistance training today.
- Suchomel TJ, Nimphius S, Stone MH. The importance of muscular strength in athletic performance. Sports Med. 2016;46(10):1419-1449. doi:10.1007/s40279-016-0486-0.
- Smith JJ, Eather N, Morgan PJ, Plotnikoff RC, Faigenbaum AD, Lubans DR. The health benefits of muscular fitness for children and adolescents: A systematic review and meta-analysis. Sports Med. 2014;44:1209-1223. doi:10.1007/s40279-014-0196-4.
- McLeod M, Breen L, Hamilton DL, Philp A. Live strong and prosper: The importance of skeletal muscle strength for healthy aging. Biogerontology. 2016;17(3):497-510. doi:10.1007/s10522-015-9631-7.
- Stamatakis E, Lee I, Bennie J, et al. Does strength promoting exercise confer unique health benefits? A pooled analysis of eleven population cohorts with all-cause, cancer, and cardiovascular mortality endpoints. Eur J Intern Med. 2017; Ahead of P:1-37. doi:10.1093/aje/kwx345/4582884.
- Volaklis KA, Halle M, Meisinger C. Muscular strength as a strong predictor of mortality: A narrative review. Eur J Intern Med. 2017;26(5):303-310. doi:10.1016/j.ejim.2015.04.013.