Most basic strength training programs (Starting Strength, 5x5, and more) recommend for optimal growth 3 training sessions per week and never train on consecutive days. This is assuming total body work outs and lifting 5RM (80-90% of 1RM) for 3 to 5 sets for each exercise.
Progress and strength gains are governed by your recovery time. You recovery time can be effected by your age, diet, fitness level, sleep, and a multitude of other factors.
If you are older (45+ or so), you might only be able to recover in enough time for 2 work outs per week.
If you are not consuming enough overall calories and protein, giving your body the building blocks to synthesize muscle, that will lengthen your recovery time.
If you are relatively new to strength training, it will take some time for your tendons, ligaments, and bones to adapt to the new stress you are placing on them. These adaptations are slower than muscle synthesis (something to do with less blood flow).
Are you getting 8 hours of sleep every night? That can make a HUGE difference.
Protocol used to optimize muscle synthesis and mitigate catabolism for workouts: Pre-workout: Consume Whey protein and Creatine 30-45 minutes before workout Workout: Consume BCAA's (add to water) during workout Post-workout: Consume mix of carbs and protein 15 minutes or so after workout.
Hope this helps! People more qualified than me can tell you the why's (glycogen, catabolism, and more). Hope you keep with the strength training and always listen to your body!
Because you're doing it right?
Seriously, lifting heavy is hard and should only be done rarely. I do high volume, heavy days once every two weeks. Other days are lower volume or lower weight. As long as you're not actually injuring yourself, soreness is ok.
A couple of suggestions, but depends on your current situation as well. 1. Get more sleep. This is absolutely key, especially if you are working out everyday. Your body needs to recover and if you aren't sleeping enough then you won't recover quickly. I'm not talking about getting 8 hours here, I'm talking about making a conscious effort to start going to bed early every night until you can wake up before your alarm every day. 2. Stretch and foam roll a lot after your heavy lift and throughout the week. After every workout is preferable.
Other things to consider- your diet (are you eating Paleo?), how many times a week do you work out, how much sleep are you currently getting?
Also, I cannot say that my answers are right or close to right but they won't hurt you and you could reap great benefits. Ask your coach for advice if you have one. Are you sure that it is DOMS and not injuries?
How long have you been lifting? If you are just getting started, you will experience DOMS (delayed onset muscle soreness) more often. Also, lifting to failure and doing eccentric lifting will cause DOMS more. Also, what are your absolute goals for lifting, and what is your current pattern? As far as what is optimum, depends on your goals. When I want to increase my bench press 1RM I only lift chest/triceps once every 5-6 days, and can easily build from 290 up to 305 or so. (I weigh 144 for reference). If I lift more often, my 1RM goes down.