Hi welcome to HCm I have gone thru your query regarding bradycardia, tiredness and back aches . It is of course a matter of concern ,bur there is reason for every symptom we experience while doing any activity . I would like to know your pulse rate , as Bradycardia is strictly defined in adults as a pulse rate below 60 beats per minute (bpm). However, few individuals are symptomatic unless the heart rate is below 50 bpm . A resting bradycardia can be normal , in trained athlet . Tiredness and back aches are natural if we over do our workuts . Limit of workouts depend upon our health , age , quality & quantity , environment , weather and even your intake of diet and your life style . When you started 15 years back , you were young . But with time you should set new limit and carry on . For your info Every day, we are bombarded with toxins in our environment and in our food which is why detoxification is such a critical process in your body & weakened immunity . If the detox process is hindered, toxins will build up in your body eventually causing acidity and toxemia. These are the root causes of nearly all diseases ,requiring modification of life style and food habits . Gulping on only medicines will not help if you don t modify your life style and food habits . By following some simple steps, you can be back in the swing of things in just a few days. Slow motion action is permitted till the problem persists . There is no better option than physical exercise. Walking is the best exercise to begin with also gives you well shaped body . .Do yoga .Stretch your back to keep it loose and avoid injury. Slow motion action is permitted till the problem persists . Exercises from left to right stretching , while standing & lying on your back ,on the ground or on hard bed , or any posture which gives you relief. Front bending not allowed.Only back bending action will help alley pains . Take balanced diet containing all essential nutrients and supplements like fiber ,protien , vitamins , minerals in natural form and antioxidant coco nut water , lemon juice , ginger ,garlic aloe vera juice ,Turmeric powder with a cup of hot milk at bed time , All help gain strong immune system & give resistance from dieases and relieve you from all pains . Take Homeo pathic Arnica 30 dose in then morning & evening / 3 days and Chammomila 30 / 1 dose at bed time. Massage with heated olive oil or an analgesic ointment and Keep good straight posture while walking . Avoid processed foods carbs , sugar , fried ,fast foods , Tea , coffee , alcohol and smoking , stress and Constipation , sleeplessnesswill produce biochemical and metabolic conditions in your body that will decrease your immunity . So avoiding is definitely the first step in the right direction to detoxing the body, boosting the immune system . All are the pillers of our strong immune system responsible for healthy disease free life. Always remember, if pain is severe or incapacitating, take rest for few seconds in between every posture . Please see your doctor / professional if problem persists . Hope this helps solves your query .Take care .All the best .Get well soon Don t hesitate to come back in case of any further query .