Did you / do you have times when you feel exhausted from the practice?
Or should it be energizing all way round?
Practice should leave one feeling energized. When we feel exhausted after practice, which we all have at some point, it is a good time to pause and closely examine how we are practicing. Here are some things to consider:
What is your breath like during practice? Ideally, the breath is steady and equally lengthened on either ends. When the breath becomes restrained or uneven it is important to stop and assess whether to close practice or begin again with steadiness.
What is the balance between effort and ease? When practice is done correctly (meaning you are not doing too much and are focused in the present moment) the movement should feel easefull. There is a certain amount of effort in the form of tapas that we put into the practice, but it should be embraced by ease and freedom of movement both in the body and in the breath. If you experience more effort then ease, I would suggest scaling back on the number of asanas you do and focus on mastering each one before moving on. Sometimes taking 8 breaths instead of 5 can help build more stamina and stability.
How is your sleep? Rest is an important part of the yogic path. It's not about the number of hours of rest that you get, but the quality. Making sure that you begin to slow down at around the same time every day, perhaps having an evening meditation or pranayama practice to soothe the nervous system. Leaving enough time between your last meal and the time you go to bed. Signing off your electronic devices a few hours before bedtime. Having a soft atmosphere in your place of rest. These are all important aspects of rest. We are so good at working hard, we must be equally good at giving our minds and bodies a chance to regroup.
What's your diet like? Keeping a clean, simple, vegetarian diet, or a diet that suits your body's needs is essential for proper energy levels. No matter how much ease you experience in your practice if your diet is off it will manifest through exhaustion at some point in time. According to Ayurveda, your biggest meal should be in the pitta time of day between 10 am and 2 pm, ending your day with a lighter meal will help your body rest, digest, and clear out any toxins accumulated in your colon. A healthy gut means a healthy you! Learn to listen to your body's nutritional needs and make sure you meet them accordingly.
How are your relationships? Keeping nourishing, healthy relationships is also an important part of feeling alive. We have all experienced what it's like to feel drained by someone. Try to surround yourself with people of all paths of life who will challenge you to grow in a positive way, or where it feels like the exchange is equal. There will always be a friend or a family member in need of your love, so its important to be nourished by many positive relationships so we can show up for those who need us during hard times. Only giving will eventually drain you. Speak good words, think good thoughts, and do good actions. When you don't, acknowledge it and learn from it.
All these things will affect your energy level and will seep into how you feel after practice. Let practice be a mirror of truth, where you can observe where you need to make changes so that you can feel at your best.