Weight training also provides functional benefits. Stronger muscles improve posture, provide better support for joints, and reduce the risk of injury from everyday activities. Older people who take up weight training can prevent some of the loss of muscle tissue that normally accompanies aging—and even regain some functional strength—and by doing so, become less frail.[33] They may be able to avoid some types of physical disability. Weight-bearing exercise also helps to prevent osteoporosis.[34] The benefits of weight training for older people have been confirmed by studies of people who began engaging in it even in their eighties and nineties.
A pre-workout may contain a variety of different ingredients, but some common ones include caffeine (energy booster), citruline malate (fatigue killer), creatine (muscle recovery), and beta-alanine (reduces fatigue and gives increased feelings of sensation). If you find you are exhausted and need a little pick me up to power through your workouts, consider implementing a pre-workout supplement into your stack.
After supplementation of creatine monohydrate (loading phase, followed by 19 weeks maintenance), creatine precursors are decreased by up to 50% (loading) or 30% (maintenance), which suggests a decrease in endogenous creatine synthesis during supplementation.[38] This appears to occur through creatine’s own positive feedback and suppression of the l-arginine:glycine amidinotransferase enzyme, the rate-limiting step in creatine synthesis, as levels of intermediates before this stage are typically elevated by up to 75%.[38]

As I mentioned earlier, the exercises that come first in your workout (aka primary compound exercises) should usually be done in the 5-8 rep range. Exercises in the middle (aka your secondary compound exercises) should usually be done in the 8-10 rep range. Exercises done at the end of your workout (which is typically where isolation exercises belong) should usually be done in the 10-15 rep range.

A commercially available pre-workout formula comprised of 2.05 g of caffeine, taurine and glucuronolactone, 7.9 g of L-leucine, L-valine, L-arginine and L-glutamine, 5 g of di-creatine citrate and 2.5 g of β-alanine mixed with 500 ml of water taken 10 minutes prior to exercise has been shown to enhance time to exhaustion during moderate intensity endurance exercise and to increase feelings of focus, energy and reduce subjective feelings of fatigue before and during endurance exercise due to a synergistic effect of the before mentioned ingredients [72]. The role of creatine in this formulation is to provide a neuroprotective function by enhancing the energy metabolism in the brain tissue, promoting antioxidant activities, improving cerebral vasculation and protecting the brain from hyperosmotic shock by acting as a brain cell osmolyte. Creatine can provide other neuroprotective benefits through stabilisation of mitochondrial membranes, stimulation of glutamate uptake into synaptic vesicles and balance of intracellular calcium homeostasis [72].
Parashos, S. A., Swearingen, C. J., Biglan, K. M., Bodis-Wollner, I., Liang, G. S., Ross, G. W., Tilley, B. C., and Shulman, L. M. Determinants of the timing of symptomatic treatment in early Parkinson disease: The National Institutes of Health Exploratory Trials in Parkinson Disease (NET-PD) Experience. Arch Neurol. 2009;66:1099-1104. View abstract.

Collectively the above investigations indicate that creatine supplementation can be an effective strategy to maintain total creatine pool during a rehabilitation period after injury as well as to attenuate muscle damage induced by a prolonged endurance training session. In addition, it seems that creatine can act as an effective antioxidant agent after more intense resistance training sessions.